Sample records for atomic force microscopy

  1. Accurate capacitive metrology for atomic force microscopy

    E-Print Network [OSTI]

    Mazzeo, Aaron D. (Aaron David), 1979-

    2005-01-01T23:59:59.000Z

    This thesis presents accurate capacitive sensing metrology designed for a prototype atomic force microscope (AFM) originally developed in the MIT Precision Motion Control Lab. The capacitive measurements use a set of ...

  2. Atomic force microscopy of biochemically tagged DNA

    SciTech Connect (OSTI)

    Ogletree, D.F.; Kolbe, W.; Spengler, S.; Salmeron, M. (Lawrence Berkeley Laboratory, CA (United States)); Hansma, H.G.; Bezanilla, M. (Univ. of California, Santa Barbara (United States)); Sano, T.; Smith, C.S.; Cantor, C.R. (Boston Univ., MA (United States))

    1993-05-01T23:59:59.000Z

    Small fragments of DNA of known length were made with the polymerase chain reaction. These fragments had biotin molecules covalently attached at their ends. They were subsequently labeled with a chimeric protein fusion between streptavidin and two immunoglobulin G-binding domains of staphyloccocal protein A. This tetrameric species was expected to bind up to four DNA molecules via their attached biotin moieties. The DNA-protein complex was deposited on mica and imaged with an atomic force microscope. The images revealed the protein chimera at the expected location at the ends of the strands of DNA as well as the expected dimers, trimers, and tetramers of DNA bound to a single protein. 25 refs., 5 figs.

  3. Non-contact atomic-level interfacial force microscopy

    SciTech Connect (OSTI)

    Houston, J.E.; Fleming, J.G.

    1997-02-01T23:59:59.000Z

    The scanning force microscopies (notably the Atomic Force Microscope--AFM), because of their applicability to nearly all materials, are presently the most widely used of the scanning-probe techniques. However, the AFM uses a deflection sensor to measure sample/probe forces which suffers from an inherent mechanical instability that occurs when the rate of change of the force with respect to the interfacial separation becomes equal to the spring constant of the deflecting member. This instability dramatically limits the breadth of applicability of AFM-type techniques to materials problems. In the course of implementing a DOE sponsored basic research program in interfacial adhesion, a self-balancing force sensor concept has been developed and incorporated into an Interfacial Force Microscopy (IFM) system by Sandia scientists. This sensor eliminates the instability problem and greatly enhances the applicability of the scanning force-probe technique to a broader range of materials and materials parameters. The impact of this Sandia development was recognized in 1993 by a Department of Energy award for potential impact on DOE programs and by an R and D 100 award for one of the most important new products of 1994. However, in its present stage of development, the IFM is strictly a research-level tool and a CRADA was initiated in order to bring this sensor technology into wide-spread availability by making it accessible in the form of a commercial instrument. The present report described the goals, approach and results of this CRADA effort.

  4. Detection of Percolating Paths in PMMA/CB Segregated Network Composites Using Electrostatic Force Microscopy and Conductive Atomic Force Microscopy

    SciTech Connect (OSTI)

    Waddell, J. [Georgia Institute of Technology; Ou, R. [Georgia Institute of Technology; Gupta, S. [Georgia Institute of Technology; Parker, A. [Georgia Institute of Technology; Gerhardt, Dr. Rosario [Georgia Institute of Technology; Seal, Katyayani [ORNL; Kalinin, Sergei V [ORNL; Baddorf, Arthur P [ORNL

    2009-01-01T23:59:59.000Z

    Composite specimens possessing polyhedral segregated network microstructures require a very small amount of nanosize filler, <1 vol %, to reach percolation because percolation occurs by accumulation of the fillers along the edges of the deformed polymer matrix particles. In this paper, electrostatic force microscopy (EFM) and conductive atomic force microscopy (C-AFM) were used to confirm the location of the nanosize fillers and the corresponding percolating paths in polymethyl methacrylate/carbon black composites. The EFM and C-AFM images revealed that the polyhedral polymer particles were coated with filler, primarily on the edges as predicted by the geometric models provided.

  5. Size effects in bimetallic nickelgold nanowires: Insight from atomic force microscopy nanoindentation

    E-Print Network [OSTI]

    Sansoz, Frederic

    Size effects in bimetallic nickel­gold nanowires: Insight from atomic force microscopy the local plastic behavior and hardness properties of electrodeposited bimetallic Ni­Au NWs ranging from 60 rights reserved. Keywords: Atomic force microscopy (AFM); Nanowire; Nickel; Gold; Nanoindentation 1

  6. Noninvasive determination of optical lever sensitivity in atomic force microscopy

    SciTech Connect (OSTI)

    Higgins, M.J.; Proksch, R.; Sader, J.E.; Polcik, M.; Mc Endoo, S.; Cleveland, J.P.; Jarvis, S.P. [Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland); Asylum Research, 6310 Hollister Ave, Santa Barbara, California 93117 (United States); Department of Mathematics and Statistics, University of Melbourne Victoria, 3010 (Australia); Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland); Asylum Research, 6310 Hollister Ave, Santa Barbara, California 93117 (United States); Centre for Research on Adaptive Nanodevices and Nanostructures (CRANN), University of Dublin, Trinity College, Dublin 2 (Ireland)

    2006-01-15T23:59:59.000Z

    Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. [Rev. Sci. Instrum. 70, 3967 (1999)] to calibrate the spring constant of the cantilever in combination with the equipartition theorem [J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 (1993)] to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity.

  7. Thermal calibration of photodiode sensitivity for atomic force microscopy

    SciTech Connect (OSTI)

    Attard, Phil; Pettersson, Torbjoern; Rutland, Mark W. [School of Chemistry F11, University of Sydney, NSW 2006 Australia (Australia); Department of Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden and Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm (Sweden)

    2006-11-15T23:59:59.000Z

    The photodiode sensitivity in the atomic force microscope is calibrated by relating the voltage noise to the thermal fluctuations of the cantilever angle. The method accounts for the ratio of the thermal fluctuations measured in the fundamental vibration mode to the total, and also for the tilt and extended tip of the cantilever. The method is noncontact and is suitable for soft or deformable surfaces where the constant compliance method cannot be used. For hard surfaces, the method can also be used to calibrate the cantilever spring constant.

  8. Contribution to crystallographic slip assessment by means of topographic measurements achieved with atomic force microscopy

    SciTech Connect (OSTI)

    Kahloun, C. [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Badji, R. [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Welding and NDT Research Centre, B. P. 64, Cheraga (Algeria); Bacroix, B., E-mail: bacroix@lpmtm.univ-paris13.fr [LPMTM - CNRS, Universite Paris 13, 99 av. J.B. Clement, 93430 Villetaneuse (France); Bouabdallah, M. [E.N.P, 10 av. Hassan Badi, 16200 El Harrah Alger (Algeria)

    2010-09-15T23:59:59.000Z

    In this paper, atomic force microscopy (AFM) is used to quantitatively characterize the plastic glide occurring during tensile deformation of a duplex 2205 stainless steel sample. We demonstrate that an appropriate treatment of the topographic image issued from AFM measurements allows precise and quantitative information about the characteristics of plastic deformation and especially the amount of crystallographic slip.

  9. Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy and ultra-small angle

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy of silica aerogels has been extensively studied mainly by scattering techniques (neutrons, X-rays, light) and atomic force microscopy (AFM) experiments have been carried out on aerogels at dierent steps of densi

  10. Topography and Mechanical Property Mapping of International Simple Glass Surfaces with Atomic Force Microscopy

    SciTech Connect (OSTI)

    Hopf, Juliane [ORNL; Pierce, Eric M [ORNL

    2014-01-01T23:59:59.000Z

    Quantitative Nanomechanical Peak Force (PF-QNM) TappingModeTM atomic force microscopy measurements are presented for the first time on polished glass surfaces. The PF-QNM technique allows for topography and mechanical property information to be measured simultaneously at each pixel. Results for the international simple glass which represents a simplified version of SON68 glass suggests an average Young s modulus of 78.8 15.1 GPa is within the experimental error of the modulus measured for SON68 glass (83.6 2 GPa) with conventional approaches. Application of the PF-QNM technique will be extended to in situ glass corrosion experiments with the goal of gaining atomic-scale insights into altered layer development by exploiting the mechanical property differences that exist between silica gel (e.g., altered layer) and pristine glass surface.

  11. Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function

    SciTech Connect (OSTI)

    Tung, Ryan C., E-mail: ryan.tung@nist.gov; Killgore, Jason P.; Hurley, Donna C. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2014-06-14T23:59:59.000Z

    We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.

  12. In situ atomic force microscopy imaging of electroprecipitated nickel hydrous oxide films in alkaline electrolytes

    SciTech Connect (OSTI)

    Chen, R.; Mo, Y.; Scherson, D.A. (Case Western Reserve Univ., Cleveland, OH (United States))

    1994-11-01T23:59:59.000Z

    In situ atomic force microscopy images of nickel hydrous oxide films electrodeposited on the basal plane of highly oriented pyrolytic graphite in alkaline electrolytes have shown that a stepwise oxidation leads to irreversible formation of wide crevices throughout the material. Upon subsequent stepwise reduction, the gaps close leaving a hairline type crack which follows the profile of the crevice. These potential induced structural rearrangements have been attributed to stresses induced by differences in the densities of the nickel hydrous oxide in the two oxidation states. 9 refs., 5 figs.

  13. Nanosecond switching in GeSe phase change memory films by atomic force microscopy

    SciTech Connect (OSTI)

    Bosse, James L.; Huey, Bryan D., E-mail: bhuey@ims.uconn.edu [Department of Materials Science and Engineering, 97 North Eagleville Road, Unit 3136, Storrs, Connecticut 06269-3136 (United States); Grishin, Ilya; Kolosov, Oleg V. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Gyu Choi, Yong [Department of Materials Science and Engineering, Korea Aerospace University, Goyang-si, Gyeonggi-do, 412-791 (Korea, Republic of); Cheong, Byung-ki; Lee, Suyoun [Electronic Materials Research Center, Korea Institute of Science and Technology, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-02-03T23:59:59.000Z

    Nanosecond scale threshold switching is investigated with conducting atomic force microscopy (AFM) for an amorphous GeSe film. Switched bits exhibit 2–3 orders of magnitude variations in conductivity, as demonstrated in phase change based memory devices. Through the nm-scale AFM probe, this crystallization was achieved with pulse durations of as low as 15?ns, the fastest reported with scanning probe based methods. Conductance AFM imaging of the switched bits further reveals correlations between the switched volume, pulse amplitude, and pulse duration. The influence of film heterogeneities on switching is also directly detected, which is of tremendous importance for optimal device performance.

  14. Switching surface polarization of atomic force microscopy probe utilizing photoisomerization of photochromic molecules

    SciTech Connect (OSTI)

    Aburaya, Yoshihiro; Nomura, Hikaru; Kageshima, Masami; Naitoh, Yoshitaka; Li, Yan Jun; Sugawara, Yasuhiro [Department of Applied Physics, Graduate School of Engineering, Osaka University 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2011-03-15T23:59:59.000Z

    An attempt to develop an atomic force microscopy (AFM) probe with optically switchable polarization is described. Modification with a single molecular layer of photochromic molecules was attempted onto a Si substrate that is a prototype for a probe surface. Polarization switching caused by alternate irradiation of UV and visible lights were detected using the electrostatic force?>spectroscopy (EFS) technique. Si substrates modified with spiropyran and azobenzene exhibited reversible polarization switching that caused changes in CPD of about 100 and 50 mV, respectively. Modification with spiropyran was also attempted onto a Si probe and resulted in a CPD change of about 100 mV. It was confirmed that modification of an AFM probe or substrate with a single molecular layer of photochromic molecules can generate surface polarization switching of a mechanically detectable level.

  15. Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy

    SciTech Connect (OSTI)

    Loganathan, Muthukumaran; Bristow, Douglas A., E-mail: dbristow@mst.edu [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri 65401 (United States)

    2014-04-15T23:59:59.000Z

    This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

  16. A serial-kinematic nanopositioner for high-speed atomic force microscopy

    SciTech Connect (OSTI)

    Wadikhaye, Sachin P., E-mail: sachin.wadikhaye@uon.edu.au; Yong, Yuen Kuan; Reza Moheimani, S. O. [School of Electrical Engineering and Computer Science, The University of Newcastle, Callaghan, NSW (Australia)

    2014-10-15T23:59:59.000Z

    A flexure-guided serial-kinematic XYZ nanopositioner for high-speed Atomic Force Microscopy is presented in this paper. Two aspects influencing the performance of serial-kinematic nanopositioners are studied in this work. First, mass reduction by using tapered flexures is proposed to increased the natural frequency of the nanopositioner. 25% increase in the natural frequency is achieved due to reduced mass with tapered flexures. Second, a study of possible sensor positioning in a serial-kinematic nanopositioner is presented. An arrangement of sensors for exact estimation of cross-coupling is incorporated in the proposed design. A feedforward control strategy based on phaser approach is presented to mitigate the dynamics and nonlinearity in the system. Limitations in design approach and control strategy are discussed in the Conclusion.

  17. Investigation of leakage current paths in n-GaN by conductive atomic force microscopy

    SciTech Connect (OSTI)

    Kim, Bumho; Park, Yongjo, E-mail: yp0520@snu.ac.kr, E-mail: eyoon@snu.ac.kr [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of)] [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Moon, Daeyoung; Nanishi, Yasushi [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)] [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Joo, Kisu [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of) [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Oh, Sewoung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Young Kuk [Korea Research Institute of Chemical Technology, Daejon 305-600 (Korea, Republic of)] [Korea Research Institute of Chemical Technology, Daejon 305-600 (Korea, Republic of); Yoon, Euijoon, E-mail: yp0520@snu.ac.kr, E-mail: eyoon@snu.ac.kr [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of) [Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-03-10T23:59:59.000Z

    We have investigated electrical characteristics of leakage current paths in n-GaN layer grown by metal-organic chemical vapor deposition with conductive-atomic force microscopy (C-AFM). The C-AFM mapping shows two kinds of leakage current paths existing in the n-GaN layer: open-core dislocation and pure screw dislocation. From the localized I-V curves measured by C-AFM, we confirmed that the open-core screw dislocation shows more significant leakage current. We explained these results in terms of a modified Schottky band model based on donor states formed by oxygen segregation at the (10?10) sidewall of the open-core screw dislocation.

  18. Advances in quantitative nanoscale subsurface imaging by mode-synthesizing atomic force microscopy

    SciTech Connect (OSTI)

    Vitry, P.; Bourillot, E.; Plassard, C.; Lacroute, Y.; Lesniewska, E. [ICB, UMR CNRS 6303 CNRS-University of Bourgogne, Dijon F-21078 (France); Tetard, L. [Nanoscience Technology Center, University of Central Florida, Orlando, Florida 32826 (United States)

    2014-08-04T23:59:59.000Z

    This paper reports on advances toward quantitative non-destructive nanoscale subsurface investigation of a nanofabricated sample based on mode synthesizing atomic force microscopy with heterodyne detection, addressing the need to correlate the role of actuation frequencies of the probe f{sub p} and the sample f{sub s} with depth resolution for 3D tomography reconstruction. Here, by developing a simple model and validating the approach experimentally through the study of the nanofabricated calibration depth samples consisting of buried metallic patterns, we demonstrate avenues for quantitative nanoscale subsurface imaging. Our findings enable the reconstruction of the sample depth profile and allow high fidelity resolution of the buried nanostructures. Non-destructive quantitative nanoscale subsurface imaging offers great promise in the study of the structures and properties of complex systems at the nanoscale.

  19. On single-molecule DNA sequencing with atomic force microscopy using functionalized carbon nanotube probes

    E-Print Network [OSTI]

    Burns, Daniel James

    2004-01-01T23:59:59.000Z

    A novel DNA sequencing method is proposed based on the specific binding nature of nucleotides and measured by an atomic force microscope (AFM). A single molecule of DNA is denatured and immobilized on an atomically fiat ...

  20. Imaging and quantitative data acquisition of biological cell walls with Atomic Force Microscopy and Scanning Acoustic Microscopy

    SciTech Connect (OSTI)

    Tittmann, B. R. [Penn State; Xi, X. [Penn State

    2014-09-01T23:59:59.000Z

    This chapter demonstrates the feasibility of Atomic Force Microscopy (AFM) and High Frequency Scanning Acoustic Microscopy (HF-SAM) as tools to characterize biological tissues. Both the AFM and the SAM have shown to provide imaging (with different resolution) and quantitative elasticity measuring abilities. Plant cell walls with minimal disturbance and under conditions of their native state have been examined with these two kinds of microscopy. After descriptions of both the SAM and AFM, their special features and the typical sample preparation is discussed. The sample preparation is focused here on epidermal peels of onion scales and celery epidermis cells which were sectioned for the AFM to visualize the inner surface (closest to the plasma membrane) of the outer epidermal wall. The nm-wide cellulose microfibrils orientation and multilayer structure were clearly observed. The microfibril orientation and alignment tend to be more organized in older scales compared with younger scales. The onion epidermis cell wall was also used as a test analog to study cell wall elasticity by the AFM nanoindentation and the SAM V(z) feature. The novelty in this work was to demonstrate the capability of these two techniques to analyze isolated, single layered plant cell walls in their natural state. AFM nanoindentation was also used to probe the effects of Ethylenediaminetetraacetic acid (EDTA), and calcium ion treatment to modify pectin networks in cell walls. The results suggest a significant modulus increase in the calcium ion treatment and a slight decrease in EDTA treatment. To complement the AFM measurements, the HF-SAM was used to obtain the V(z) signatures of the onion epidermis. These measurements were focused on documenting the effect of pectinase enzyme treatment. The results indicate a significant change in the V(z) signature curves with time into the enzyme treatment. Thus AFM and HF-SAM open the door to a systematic nondestructive structure and mechanical property study of complex biological cell walls. A unique feature of this approach is that both microscopes allow the biological samples to be examined in their natural fluid (water) environment.

  1. A system dynamics approach to user independence in high speed atomic force microscopy

    E-Print Network [OSTI]

    Burns, Daniel James

    2010-01-01T23:59:59.000Z

    As progress in molecular biology and nanotechnology continues, demand for rapid and high quality image acquisition has increased to the point where the limitations of atomic force microscopes (AFM) become impediments to ...

  2. Nanomechanical and topographical imaging of living cells by Atomic Force Microscopy with colloidal probes

    E-Print Network [OSTI]

    Luca Puricelli; Massimiliano Galluzzi; Carsten Schulte; Alessandro Podestà; Paolo Milani

    2015-02-05T23:59:59.000Z

    Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells' fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cell elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured elastic modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in cell elasticity induced by the action of a cytoskeleton-targeting drug.

  3. Dielectric spectroscopy at the nanoscale by atomic force microscopy: A simple model linking materials properties and experimental response

    SciTech Connect (OSTI)

    Miccio, Luis A., E-mail: luisalejandro-miccio@ehu.es; Colmenero, Juan [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Donostia International Physics Center, P. M. de Lardizabal 4, 20018 San Sebastián (Spain); Departamento de Física de Materiales (UPV/EHU), 20080 San Sebastián (Spain); Kummali, Mohammed M.; Alegría, Ángel [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Departamento de Física de Materiales (UPV/EHU), 20080 San Sebastián (Spain); Schwartz, Gustavo A. [Centro de Física de Materiales (CSIC-UPV/EHU), P. M. de Lardizabal 5, 20018 San Sebastián (Spain); Donostia International Physics Center, P. M. de Lardizabal 4, 20018 San Sebastián (Spain)

    2014-05-14T23:59:59.000Z

    The use of an atomic force microscope for studying molecular dynamics through dielectric spectroscopy with spatial resolution in the nanometer scale is a recently developed approach. However, difficulties in the quantitative connection of the obtained data and the material dielectric properties, namely, frequency dependent dielectric permittivity, have limited its application. In this work, we develop a simple electrical model based on physically meaningful parameters to connect the atomic force microscopy (AFM) based dielectric spectroscopy experimental results with the material dielectric properties. We have tested the accuracy of the model and analyzed the relevance of the forces arising from the electrical interaction with the AFM probe cantilever. In this way, by using this model, it is now possible to obtain quantitative information of the local dielectric material properties in a broad frequency range. Furthermore, it is also possible to determine the experimental setup providing the best sensitivity in the detected signal.

  4. Study of anion adsorption at the gold--aqueous solution interface by atomic force microscopy

    SciTech Connect (OSTI)

    Biggs, S.; Mulvaney, P.; Grieser, F. (Univ. of Melbourne (Australia)); Zukoski, C.F. (Univ. of Illinois, Urbana, IL (United States))

    1994-10-05T23:59:59.000Z

    The forces between a gold coated colloidal silica sphere and a pure gold plate have been measured in aqueous solution as a function of electrolyte concentration using an atomic force microscope (AFM). Forces in the presence of gold(III) chloride (HAuCl[sub 4]), sodium chloride, and trisodium citrate were recorded as a function of concentration. Each of these anion species is present during the formation of colloidal gold by the reduction of gold(III) chloride with trisodium citrate. In pure water the force between the gold surfaces was exclusively attractive. In sodium chloride or trisodium citrate solution a repulsive interaction was observed which is attributed to the adsorption of these anions at the gold/water interface. The observed interaction force in gold(III) chloride solution was always attractive, the surface potential never exceeding 20 mV. Data taken in aqueous solutions of citrate and chloride ions together suggested that the citrate ions were preferentially adsorbed to the surface of the gold. Addition of gold(III) chloride to the AFM liquid cell after the pre-adsorption of citrate anions caused the force of interaction to change from a repulsvie force to an attractive one initially as the gold(III) chloride was reduced to gold by the citrate anions. 33 refs., 11 figs.

  5. Electrical transport and mechanical properties of alkylsilane self-assembled monolayers on silicon surfaces probed by atomic force microscopy

    SciTech Connect (OSTI)

    Park, Jeong Young; Qi, Yabing; Ashby, Paul D.; Hendriksen, Bas L.M.; Salmeron, Miquel

    2009-02-06T23:59:59.000Z

    The correlation between molecular conductivity and mechanical properties (molecular deformation and frictional responses) of hexadecylsilane self-assembled monolayers was studied with conductive probe atomic force microscopy/friction force microscopy in ultrahigh vacuum. Current and friction were measured as a function of applied pressure, simultaneously, while imaging the topography of self-assembled monolayer molecule islands and silicon surfaces covered with a thin oxide layer. Friction images reveal lower friction over the molecules forming islands than over the bare silicon surface, indicating the lubricating functionality of alkylsilane molecules. By measuring the tunneling current change due to changing of the height of the molecular islands by tilting the molecules under pressure from the tip, we obtained an effective conductance decay constant ({beta}) of 0.52/{angstrom}.

  6. Noncontact atomic force microscopy simulator with phase-locked-loop controlled frequency detection and excitation

    E-Print Network [OSTI]

    Nony, L; Schaer, D; Pfeiffer, O; Wezel, A; Meyer, E; Nony, Laurent; Baratoff, Alexis Prof.; Schaer, Dominique; Pfeiffer, Oliver; Wezel, Adrian; Meyer, Ernst

    2006-01-01T23:59:59.000Z

    A simulation of an atomic force microscope operating in the constant amplitude dynamic mode is described. The implementation mimics the electronics of a real setup including a digital phase-locked loop (PLL). The PLL is not only used as a very sensitive frequency detector, but also to generate the time-dependent phase shifted signal driving the cantilever. The optimum adjustments of individual functional blocks and their joint performance in typical experiments are determined in detail. Prior to testing the complete setup, the performances of the numerical PLL and of the amplitude controller were ascertained to be satisfactory compared to those of the real components. Attention is also focused on the issue of apparent dissipation, that is, of spurious variations in the driving amplitude caused by the nonlinear interaction occurring between the tip and the surface and by the finite response times of the various controllers. To do so, an estimate of the minimum dissipated energy that is detectable by the instru...

  7. On the use of peak-force tapping atomic force microscopy for quantification of the local elastic modulus in hardened cement paste

    SciTech Connect (OSTI)

    Trtik, Pavel, E-mail: pavel.trtik@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland); Kaufmann, Josef [Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland); Volz, Udo [Bruker Nano GmbH, Mannheim (Germany)

    2012-01-15T23:59:59.000Z

    A surface of epoxy-impregnated hardened cement paste was investigated using a novel atomic force microscopy (AFM) imaging mode that allows for the quantitative mapping of the local elastic modulus. The analyzed surface was previously prepared using focussed ion beam milling. The same surface was also characterized by electron microscopy and energy-dispersive X-ray spectroscopy. We demonstrate the capability of this quantitative nanomechanical mapping to provide information on the local distribution of the elastic modulus (from about 1 to about 100 GPa) with a spatial resolution in the range of decananometers, that corresponds to that of low-keV back-scattered electron imaging. Despite some surface roughness which affects the measured nanomechanical properties it is shown that topography, adhesion and Young's modulus can be clearly distinguished. The quantitative mapping of the local elastic modulus is able to discriminate between phases in the cement paste microstructure that cannot be distinguished from the corresponding back-scattered electron images.

  8. Investigations into Protein-Surface Interactions via Atomic Force Microscopy and Surface Plasmon Resonance

    E-Print Network [OSTI]

    Settle, Jenifer Kaye

    2012-08-31T23:59:59.000Z

    microscopy and surface plasmon resonance. Chapter one provides background information on protein surfaces interactions. Chapter 2 summarizes the techniques and surfaces utilized in the investigations in the following chapters. Chapter 3 provides background...

  9. Imaging and measuring the biophysical properties of Fc gamma receptors on single macrophages using atomic force microscopy

    SciTech Connect (OSTI)

    Li, Mi [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China) [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Lianqing, E-mail: lqliu@sia.cn [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China)] [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xi, Ning [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China)] [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong (China); Wang, Yuechao [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China)] [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Xiao, Xiubin [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)] [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China); Zhang, Weijing, E-mail: zhangwj3072@163.com [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)] [Department of Lymphoma, Affiliated Hospital of Military Medical Academy of Sciences, Beijing 100071 (China)

    2013-09-06T23:59:59.000Z

    Highlights: •Nanoscale cellular ultra-structures of macrophages were observed. •The binding affinities of Fc?Rs were measured directly on macrophages. •The nanoscale distributions of Fc?Rs were mapped on macrophages. -- Abstract: Fc gamma receptors (Fc?R), widely expressed on effector cells (e.g., NK cells, macrophages), play an important role in clinical cancer immunotherapy. The binding of Fc?Rs to the Fc portions of antibodies that are attached to the target cells can activate the antibody-dependent cell-mediated cytotoxicity (ADCC) killing mechanism which leads to the lysis of target cells. In this work, we used atomic force microscopy (AFM) to observe the cellular ultra-structures and measure the biophysical properties (affinity and distribution) of Fc?Rs on single macrophages in aqueous environments. AFM imaging was used to obtain the topographies of macrophages, revealing the nanoscale cellular fine structures. For molecular interaction recognition, antibody molecules were attached onto AFM tips via a heterobifunctional polyethylene glycol (PEG) crosslinker. With AFM single-molecule force spectroscopy, the binding affinities of Fc?Rs were quantitatively measured on single macrophages. Adhesion force mapping method was used to localize the Fc?Rs, revealing the nanoscale distribution of Fc?Rs on local areas of macrophages. The experimental results can improve our understanding of Fc?Rs on macrophages; the established approach will facilitate further research on physiological activities involved in antibody-based immunotherapy.

  10. Atomic force and scanning tunneling microscopy analysis of palladium and silver nanophase materials

    E-Print Network [OSTI]

    Sattler, Klaus

    . INTRODUCTION Nanophase materials consolidated from atom clusters produced by the gas condensation method be made by gas condensation, not only at the labo- ratory scale but also in commercial production and properties of nano- phase materials assembled by consolidating gas-condensed atom clusters in vacuum have

  11. Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P. Rokhinson, Haizhou Yin, D. C. Tsui, and J. C. Sturm

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P features in strained SiGe alloys. When directly oxidizing SiGe alloys, minimum line widths of 20nm were on SiGe alloys is slightly less than that on Si. Finally, this method was used to successfully cut

  12. An in-vivo study of electrical charge distribution on the bacterial cell wall by Atomic Force Microscopy in vibrating force mode

    E-Print Network [OSTI]

    Christian Marliere; Samia Dhahri

    2015-04-13T23:59:59.000Z

    We report an in-vivo electromechanical Atomic Force Microscopy (AFM) study of charge distribution on the cell wall of Gram plus Rhodococcus wratislaviensis bacteria, naturally adherent to a glass substrate, in physiological conditions. The method presented in this paper relies on a detailed study of AFM approach-retract curves giving the variation of the interaction force versus distance between tip and sample. In addition to classical height and mechanical (as stiffness) data, mapping of local electrical properties, as bacterial surface charge, was proved to be feasible at a spatial resolution better than few tens of nanometers. This innovative method relies on the measurement of the cantilever's surface stress through its deflection far from (higher than 10nm) the repulsive contact zone. The variations of surface stress come from modification of electrical surface charge of the cantilever (as in classical electrocapillary measurements) likely stemming from its charging during contact of both tip and sample electrical double layers. This method offers an important improvement in local electrical and electrochemical measurements at the solid-liquid interface particularly in high-molarity electrolytes when compared to technics focused on the direct use of electrostatic force. It thus opens a new way to directly investigate in-situ biological electrical surface processes involved in numerous practical and fundamental problems as bacterial adhesion, biofilm formation, microbial fuel cell, etc.

  13. Effect of plasma CVD operating temperature on nanomechanical properties of TiC nanostructured coating investigated by atomic force microscopy

    SciTech Connect (OSTI)

    Shanaghi, Ali, E-mail: alishanaghi@gmail.com [Materials Engineering Department, Faculty of Engineering, Malayer University, P.O. Box: 95863-65719, Malayer (Iran, Islamic Republic of)] [Materials Engineering Department, Faculty of Engineering, Malayer University, P.O. Box: 95863-65719, Malayer (Iran, Islamic Republic of); Rouhaghdam, Ali Reza Sabour, E-mail: sabour01@modares.ac.ir [Surface Engineering Laboratory, Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Ahangarani, Shahrokh, E-mail: sh.ahangarani@gmail.com [Advanced Materials and Renewable Energies Department, Iranian Research Organization for Science and Technology, P.O. Box 15815-3538, Tehran (Iran, Islamic Republic of)] [Advanced Materials and Renewable Energies Department, Iranian Research Organization for Science and Technology, P.O. Box 15815-3538, Tehran (Iran, Islamic Republic of); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2012-09-15T23:59:59.000Z

    Highlights: ? The TiC{sub x} nanostructure coatings have been deposited by PACVD method. ? Dominant mechanism of growth structure at 490 °C is island-layer type. ? TiC{sub x} nanostructure coating applied at 490 °C, exhibits lowest friction coefficient. ? Young's moduli are 289.9, 400 and 187.6 GPa for 470, 490 and 510 °C, respectively. ? This higher elastic modulus and higher hardness of nanocoating obtain at 490 °C. -- Abstract: The structure, composition, and mechanical properties of nanostructured titanium carbide (TiC) coatings deposited on H{sub 11} hot-working tool steel by pulsed-DC plasma assisted chemical vapor deposition at three different temperatures are investigated. Nanoindentation and nanoscratch tests are carried out by atomic force microscopy to determine the mechanical properties such as hardness, elastic modulus, surface roughness, and friction coefficient. The nanostructured TiC coatings prepared at 490 °C exhibit lower friction coefficient (0.23) than the ones deposited at 470 and 510 °C. Increasing the deposition temperature reduces the Young's modulus and hardness. The overall superior mechanical properties such as higher hardness and lower friction coefficient render the coatings deposited at 490 °C suitable for wear resistant applications.

  14. Calibration of measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy using a contact detection method

    SciTech Connect (OSTI)

    Liu Zhen; Jeong, Younkoo; Menq, Chia-Hsiang [Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2013-02-15T23:59:59.000Z

    An accurate experimental method is proposed for on-spot calibration of the measurement sensitivities of multiple micro-cantilever dynamic modes in atomic force microscopy. One of the key techniques devised for this method is a reliable contact detection mechanism that detects the tip-surface contact instantly. At the contact instant, the oscillation amplitude of the tip deflection, converted to that of the deflection signal in laser reading through the measurement sensitivity, exactly equals to the distance between the sample surface and the cantilever base position. Therefore, the proposed method utilizes the recorded oscillation amplitude of the deflection signal and the base position of the cantilever at the contact instant for the measurement sensitivity calibration. Experimental apparatus along with various signal processing and control modules was realized to enable automatic and rapid acquisition of multiple sets of data, with which the calibration of a single dynamic mode could be completed in less than 1 s to suppress the effect of thermal drift and measurement noise. Calibration of the measurement sensitivities of the first and second dynamic modes of three micro-cantilevers having distinct geometries was successfully demonstrated. The dependence of the measurement sensitivity on laser spot location was also experimentally investigated. Finally, an experiment was performed to validate the calibrated measurement sensitivity of the second dynamic mode of a micro-cantilever.

  15. Selection of higher eigenmode amplitude based on dissipated power and virial contrast in bimodal atomic force microscopy

    SciTech Connect (OSTI)

    Diaz, Alfredo J.; Eslami, Babak; López-Guerra, Enrique A.; Solares, Santiago D., E-mail: ssolares@gwu.edu [Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-09-14T23:59:59.000Z

    This paper explores the effect of the amplitude ratio of the higher to the fundamental eigenmode in bimodal atomic force microscopy (AFM) on the phase contrast and the dissipated power contrast of the higher eigenmode. We explore the optimization of the amplitude ratio in order to maximize the type of contrast that is most relevant to the particular study. Specifically, we show that the trends in the contrast range behave differently for different quantities, especially the dissipated power and the phase, with the former being more meaningful than the latter (a similar analysis can be carried out using the virial, for which we also provide a brief example). Our work is based on numerical simulations using two different conservative-dissipative tip-sample models, including the standard linear solid and the combination of a dissipation coefficient with a conservative model, as well as experimental images of thin film Nafion{sup ®} proton exchange polymers. We focus on the original bimodal AFM method, where the higher eigenmode is driven with constant amplitude and frequency (i.e., in “open loop”).

  16. Frequency-modulated atomic force microscopy operation by imaging at the frequency shift minimum: The dip-df mode

    SciTech Connect (OSTI)

    Rode, Sebastian; Schreiber, Martin; Kühnle, Angelika; Rahe, Philipp, E-mail: rahe@uni-mainz.de [Institut für Physikalische Chemie, Fachbereich Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz (Germany)] [Institut für Physikalische Chemie, Fachbereich Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz (Germany)

    2014-04-15T23:59:59.000Z

    In frequency modulated non-contact atomic force microscopy, the change of the cantilever frequency (?f) is used as the input signal for the topography feedback loop. Around the ?f(z) minimum, however, stable feedback operation is challenging using a standard proportional-integral-derivative (PID) feedback design due to the change of sign in the slope. When operated under liquid conditions, it is furthermore difficult to address the attractive interaction regime due to its often moderate peakedness. Additionally, the ?f signal level changes severely with time in this environment due to drift of the cantilever frequency f{sub 0} and, thus, requires constant adjustment. Here, we present an approach overcoming these obstacles by using the derivative of ?f with respect to z as the input signal for the topography feedback loop. Rather than regulating the absolute value to a preset setpoint, the slope of the ?f with respect to z is regulated to zero. This new measurement mode not only makes the minimum of the ?f(z) curve directly accessible, but it also benefits from greatly increased operation stability due to its immunity against f{sub 0} drift. We present isosurfaces of the ?f minimum acquired on the calcite CaCO{sub 3}(101{sup ¯}4) surface in liquid environment, demonstrating the capability of our method to image in the attractive tip-sample interaction regime.

  17. Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy

    E-Print Network [OSTI]

    Bristol, University of

    .1063/1.3475506 Direct observation of electron emission site on boron-doped polycrystalline diamond thin films using or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force

  18. Topography, complex refractive index, and conductivity of graphene layers measured by correlation of optical interference contrast, atomic force, and back scattered electron microscopy

    SciTech Connect (OSTI)

    Vaupel, Matthias, E-mail: Matthias.vaupel@zeiss.com; Dutschke, Anke [Training Application Support Center, Carl Zeiss Microscopy GmbH, Königsallee 9-21, 37081 Göttingen (Germany); Wurstbauer, Ulrich; Pasupathy, Abhay [Department of Physics, Columbia University New York, 538 West 120th Street, New York, New York 10027 (United States); Hitzel, Frank [DME Nanotechnologie GmbH, Geysostr. 13, D-38106 Braunschweig (Germany)

    2013-11-14T23:59:59.000Z

    The optical phase shift by reflection on graphene is measured by interference contrast microscopy. The height profile across graphene layers on 300?nm thick SiO{sub 2} on silicon is derived from the phase profile. The complex refractive index and conductivity of graphene layers on silicon with 2?nm thin SiO{sub 2} are evaluated from a phase profile, while the height profile of the layers is measured by atomic force microscopy. It is observed that the conductivity measured on thin SiO{sub 2} is significantly greater than on thick SiO{sub 2}. Back scattered electron contrast of graphene layers is correlated to the height of graphene layers.

  19. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C.; Wang, Chengpu

    2006-08-22T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  20. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V.; Wang, Chengpu

    2004-11-16T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  1. True atomic-scale imaging of a spinel Li{sub 4}Ti{sub 5}O{sub 12}(111) surface in aqueous solution by frequency-modulation atomic force microscopy

    SciTech Connect (OSTI)

    Kitta, Mitsunori, E-mail: m-kitta@aist.go.jp; Kohyama, Masanori [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Onishi, Hiroshi [Department of Chemistry, Graduate School of Science, Kobe University 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-09-15T23:59:59.000Z

    Spinel-type lithium titanium oxide (LTO; Li{sub 4}Ti{sub 5}O{sub 12}) is a negative electrode material for lithium-ion batteries. Revealing the atomic-scale surface structure of LTO in liquid is highly necessary to investigate its surface properties in practical environments. Here, we reveal an atomic-scale image of the LTO(111) surface in LiCl aqueous solution using frequency-modulation atomic force microscopy. Atomically flat terraces and single steps having heights of multiples of 0.5?nm were observed in the aqueous solution. Hexagonal bright spots separated by 0.6?nm were also observed on the flat terrace part, corresponding to the atomistic contrast observed in the ultrahigh vacuum condition, which suggests that the basic atomic structure of the LTO(111) surface is retained without dramatic reconstruction even in the aqueous solution.

  2. Atomic Force Microscope

    SciTech Connect (OSTI)

    Day, R.D.; Russell, P.E.

    1988-12-01T23:59:59.000Z

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  3. Study of structural order in porphyrin-fullerene dyad ZnDHD6ee monolayers by electron diffraction and atomic force microscopy

    SciTech Connect (OSTI)

    D'yakova, Yu. A.; Suvorova, E. I.; Orekhov, Andrei S.; Orekhov, Anton S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Alekseev, A. S. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)] [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Gainutdinov, R. V.; Klechkovskaya, V. V., E-mail: klechvv@ns.crys.ras.ru; Tereschenko, E. Yu. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Tkachenko, N. V.; Lemmetyinen, H. [Tampere University of Technology (Finland)] [Tampere University of Technology (Finland); Feigin, L. A.; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15T23:59:59.000Z

    The structure of porphyrin-fullerene dyad ZnDHD6ee monolayers formed on the surface of aqueous subphase in a Langmuir trough and transferred onto solid substrates has been studied. The data obtained are interpreted using simulation of the structure of isolated molecules and their packing in monolayer and modeling of diffraction patterns from molecular aggregates having different sizes and degrees of order. Experiments on the formation of condensed ZnDHD6ee monolayers are described. The structure of these monolayers on a water surface is analyzed using {pi}-A isotherms. The structure of the monolayers transferred onto solid substrates is investigated by electron diffraction and atomic force microscopy. The unit-cell parameters of two-dimensional domains, which are characteristic of molecular packing in monolayers and deposited films, are determined. Domains are found to be organized into a texture (the molecular axes are oriented by the [001] direction perpendicular to the substrate). The monolayers contain a limited number of small 3D domains.

  4. On advancement of high speed atomic force microscope technology

    E-Print Network [OSTI]

    SooHoo, Kimberly E

    2008-01-01T23:59:59.000Z

    High speed atomic force microscopy (AFM) is a developing process in which nanoscale objects, such as crystal structures or strands of DNA, can be imaged at rates fast enough to watch processes as they occur. Although current ...

  5. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    SciTech Connect (OSTI)

    Koffas, Telly Stelianos

    2004-05-15T23:59:59.000Z

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to the surface in order to minimize the total surface energy. With an understanding of the structural and environmental parameters which govern polymer surface structure, SFG is then used to explore the effects of surface hydrophobicity and solvent polarity on the orientation and ordering of amphiphilic neutral polymers adsorbed at the solid/liquid interface. SFG spectra show that poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) adsorb with their hydrophobic moieties preferentially oriented toward hydrophobic polystyrene surfaces. These same moieties, however, disorder when adsorbed onto a hydrophilic silica/water interface. Water is identified as a critical factor for mediating the orientation and ordering of hydrophobic moieties in polymers adsorbed at hydrophobic interfaces. The role of bulk water content and water vapor, as they influence hydrogel surface structure and mechanics, continues to be explored in the next series of experiments. A method was developed to probe the surface viscoelastic properties of hydroxylethyl methacrylate (HEMA) based contact lens materials by analyzing AFM force-distance curves. AFM analysis indicates that the interfacial region is dehydrated, relative to the bulk. Experiments performed on poly(HEMA+MA) (MA = methacrylic acid), a more hydrophilic copolymer with greater bulk water content, show even greater water depletion at the surface. SFG spectra, as well as surface energy arguments, suggest that the more hydrophilic polymer component (such as MA) is not favored at the air interface; this may explain anomalies in water retention at the hydrogel surface. Adsorption of lysozyme onto poly(HEMA+MA) was found to further reduce near-surface viscous behavior, suggesting lower surface water content. Lastly, protein adsorption is studied using a model polymer system of polystyrene covalently bound with a monolayer of bovine serum albumin. SFG results indicate that some amino acid residues in proteins adopt preferred orientations. SFG spectra also show that the phenyl rings of the bare polystyrene substrate in contact with air or

  6. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C. (Port Jefferson, NY); Wang, Chengpu (Upton, NY)

    2003-01-01T23:59:59.000Z

    An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

  7. Detection of secondary phases in duplex stainless steel by magnetic force microscopy and scanning Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Ramírez-Salgado, J. [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Domínguez-Aguilar, M.A., E-mail: madoming@imp.mx [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Castro-Domínguez, B. [University of Tokyo, Department of Chemical System Engineering, Faculty of Engineering Bldg. 5, 7F 722, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113–8656 (Japan); Hernández-Hernández, P. [Instituto Mexicano del Petróleo, Dirección de Investigación y Posgrado, Eje Central Norte Lázaro Cárdenas, No. 152, 07730 D.F., México (Mexico); Newman, R.C. [University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College Street, Toronto M5S 3E5 (Canada)

    2013-12-15T23:59:59.000Z

    The secondary phase transformations in a commercial super duplex stainless steel were investigated by micro-chemical analyses and high resolution scanning probe microscopy. Energy dispersive X-ray and electron probe detected ferrite and austenite as well as secondary phases in unetched aged duplex stainless steel type 25Cr-7Ni-3Mo. Volta potential indicated that nitride and sigma appeared more active than ferrite, while secondary austenite and austenite presented a nobler potential. Reversal order in nobility is thought to be attributable to the potential ranking provided by oxide nature diversity as a result of secondary phase surface compositions on steel. After eutectoid transformation, secondary austenite was detected by electron probe microanalysis, whereas atomic force microscopy distinguished this phase from former austenite by image contrast. Magnetic force microscopy revealed a “ghosted” effect on the latter microstructure probably derived from metal memory reminiscence of mechanical polishing at passivity and long range magnetic forces of ferrite phase. - Highlights: • Nobility detection of secondary phases by SKPFM in DSS particles is not a straightforward procedure. • As Volta potential and contrast are not always consistent SKPFM surface oxides is thought played an important role in detection. • AFM distinguished secondary austenite from former austenite by image contrast though SEM required EPMA.

  8. Polymer Filler Aging and Failure Studied by Lateral Force Microscopy

    SciTech Connect (OSTI)

    Ratto, T; Saab, A P

    2009-05-27T23:59:59.000Z

    In the present work, we study, via force microscopy, the basic physical interactions of a single bead of silica filler with a PDMS matrix both before and after exposure to gamma radiation. Our goal was to confirm our results from last year, and to explore force microscopy as a means of obtaining particle-scale polymer/filler interactions suitable for use as empirical inputs to a computational model consisting of an ensemble of silica beads embedded in a PDMS matrix. Through careful calibration of a conventional atomic force microscope, we obtained both normal and lateral force data that was fitted to yield adhesion, surface shear modulus, and friction of a 1 {micro}m silica bead in contact with PDMS layers of various thickness. Comparison of these terms before and after gamma exposure indicated that initially, radiation exposure lead to softening of the PDMS, but eventually resulted in stiffening. Simultaneously, adhesion between the polymer and silica decreased. This could indicate a serious failure path for filled PDMS exposed to radiation, whereby stiffening of the bulk polymer leads to loss of compressive elastic behavior, while a decrease in polymer filler adhesion results in an increased likelihood of stress failure under load. In addition to further testing of radiation damaged polymers, we also performed FEA modeling of silica beads in a silicone matrix using the shear modulus and adhesion values isolated from the force microscopy experiments as model inputs. The resulting simulation indicated that as a polymer stiffens due to impinging radiation, it also undergoes weakening of adhesion to the filler. The implication is that radiation induces a compound failure mode in filled polymer systems.

  9. Stress-enhanced ion diffusion at the vicinity of a crack tip as evidenced by atomic force microscopy in silicate glasses

    E-Print Network [OSTI]

    Demouchy, Sylvie

    microscopy in silicate glasses F. Ce´larie´ a , M. Ciccotti b , C. Marlie`re c,* a Institute of Non The slow advance of a crack in soda-silicate glasses was studied at nanometer scale by in-situ and real in the silicate structure [A. Meyer et al., Phys. Rev. Let. 93 (2004) 027801]. � 2006 Elsevier B.V. All rights

  10. PAPER www.rsc.org/loc | Lab on a Chip Open micro-fluidic system for atomic force microscopy-guided in situ

    E-Print Network [OSTI]

    by light harvesting complexes, which funnel that energy into the reaction centers of the photosynthetic electron transport chain, causing a charge separation that provides the driving force to split water cells and has the potential to be exploited by direct extraction of energetic electrons from

  11. High-speed force mapping on living cells with a small cantilever atomic force microscope

    SciTech Connect (OSTI)

    Braunsmann, Christoph; Seifert, Jan; Rheinlaender, Johannes; Schäffer, Tilman E., E-mail: Tilman.Schaeffer@uni-tuebingen [Institute of Applied Physics and LISA, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen (Germany)

    2014-07-15T23:59:59.000Z

    The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ?10?100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed.

  12. High-temperature piezoresponse force microscopy B. Bhatia,1

    E-Print Network [OSTI]

    King, William P.

    High-temperature piezoresponse force microscopy B. Bhatia,1 J. Karthik,2 D. G. Cahill,1,2 L. W September 2011; published online 24 October 2011) We report high temperature piezoresponse force microscopy resistive heater allows local temperature control up to 1000 C with minimal electrostatic interactions

  13. Atomic force microscopy and x-ray photoelectron spectroscopy investigations of the morphology and chemistry of a PdCl{sub 2}/SnCl{sub 2} electroless plating catalysis system adsorbed onto shape memory alloy particles

    SciTech Connect (OSTI)

    Silvain, J.F.; Fouassier, O.; Lescaux, S. [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB) - CNRS, Universite de Bordeaux 1, 87 Avenue du Dr A. Schweitzer, F-33608 PESSAC (France); Veeco, Z.I. de la Gaudree, 11 Rue Marie Poussepin, F-91412 Dourdain (France)

    2004-11-01T23:59:59.000Z

    A study of the different stages of the electroless deposition of copper on micronic NiTi shape memory alloy particles activated by one-step and two-step methods has been conducted from both a chemical and a morphological point of view. The combination of x-ray photoelectron spectroscopy (XPS) measurements and atomic force microscopy (AFM) imaging has allowed detection of the distribution of the formed compounds and depth quantification and estimation of the surface topographic parameters. For the two-step method, at the sensitization of the early stages, it is observed by AFM that Sn is absorbed in form of clusters that tend to completely cover the surface and form a continuous film. XPS analysis have shown that Sn and Pd are first absorbed in form of oxide (SnO{sub 2} and PdO) and hydroxide [Sn(OH){sub 4}]. After the entire sensitization step, the NiTi substrate is covered with Sn-based compounds. After the sensitization and the activation steps the powder roughness increases. Behavior of the Sn and Pd growth for the one-step method does not follow the behavior found for the two-step method. Indeed, XPS analysis shows a three-dimensional (3D) growth of Pd clusters on top of a mixture of metallic tin, oxide (SnO) and hydroxide [Sn(OH){sub 2}]. These Pd clusters are covered with a thin layer of Pd-oxide contamination induced by the electroless process. The mean roughness for the one-step and two-step processes are equivalent. After copper deposition, the decrease of mean roughness is attributed to a filling of surface valleys, observed after the Sn-Pd coating step.

  14. VOLUME 76, NUMBER 8 P H Y S I C A L R E V I E W L E T T E R S 19 FEBRUARY 1996 Compliance Measurements of Confined Polystyrene Solutions by Atomic Force Microscopy

    E-Print Network [OSTI]

    of Chemistry, McGill University, Montreal, Canada H3A 2K6 4 Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131-1096 (Received 16 August 1995) The use of the atomic force microscope (AFM) as a local probe for elastohydrodynamic lubrication is discussed. Compliances are measured with a modified

  15. Trapping atoms using nanoscale quantum vacuum forces

    E-Print Network [OSTI]

    D. E. Chang; K. Sinha; J. M. Taylor; H. J. Kimble

    2013-10-22T23:59:59.000Z

    Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here, we show that it is possible to tailor the vacuum forces themselves to provide strong trapping potentials. The trapping scheme takes advantage of the attractive ground state potential and adiabatic dressing with an excited state whose potential is engineered to be resonantly enhanced and repulsive. This procedure yields a strong metastable trap, with the fraction of excited state population scaling inversely with the quality factor of the resonance of the dielectric structure. We analyze realistic limitations to the trap lifetime and discuss possible applications that might emerge from the large trap depths and nanoscale confinement.

  16. Friction forces on atoms after acceleration

    E-Print Network [OSTI]

    Francesco Intravaia; Vanik E. Mkrtchian; Stefan Buhmann; Stefan Scheel; Diego A. R. Dalvit; Carsten Henkel

    2015-02-04T23:59:59.000Z

    The aim of this paper is to revisit the calculation of atom-surface quantum friction in the quantum field theory formulation put forward by Barton [New J. Phys. 12 (2010) 113045]. We show that the power dissipated into field excitations and the associated friction force depend on how the atom is boosted from being initially at rest to a configuration in which it is moving at constant velocity (v) parallel to the planar interface. In addition, we point out that there is a subtle cancellation between the one-photon and part of the two-photon dissipating power, resulting in a leading order contribution to the frictional power which goes as v^4. These results are also confirmed by an alternative calculation of the average radiation force, which scales as v^3.

  17. Measurement of friction coefficients with the atomic force microscope

    E-Print Network [OSTI]

    Attard, Phil

    Measurement of friction coefficients with the atomic force microscope Phil Attard1, Johanna axial method for measuring the friction coefficient with the atomic force microscope is given measurement by measuring the difference between the constant compliance slopes of the extend and retract force

  18. Physical mechanisms of megahertz vibrations and nonlinear detection in ultrasonic force and related microscopies

    SciTech Connect (OSTI)

    Bosse, J. L.; Huey, B. D. [Department of Materials Science and Engineering, 97 North Eagleville Road, Unit 3136, Storrs, Connecticut 06269-3136 (United States); Tovee, P. D.; Kolosov, O. V., E-mail: o.kolosov@lancaster.ac.uk [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-04-14T23:59:59.000Z

    Use of high frequency (HF) vibrations at MHz frequencies in Atomic Force Microscopy (AFM) advanced nanoscale property mapping to video rates, allowed use of cantilever dynamics for mapping nanomechanical properties of stiff materials, sensing ?s time scale phenomena in nanostructures, and enabled detection of subsurface features with nanoscale resolution. All of these methods critically depend on the generally poor characterized HF behaviour of AFM cantilevers in contact with a studied sample, spatial and frequency response of piezotransducers, and transfer of ultrasonic vibrations between the probe and a specimen. Focusing particularly on Ultrasonic Force Microscopy (UFM), this work is also applicable to waveguide UFM, heterodyne force microscopy, and near-field holographic microscopy, all methods that exploit nonlinear tip-surface force interactions at high frequencies. Leveraging automated multidimensional measurements, spectroscopic UFM (sUFM) is introduced to investigate a range of common experimental parameters, including piezotransducer excitation frequency, probed position, ultrasonic amplitude, cantilever geometry, spring constant, and normal force. Consistent with studies of influence of each of these factors, the data-rich sUFM signatures allow efficient optimization of ultrasonic-AFM based measurements, leading to best practices recommendations of using longer cantilevers with lower fundamental resonance, while at the same time increasing the central frequency of HF piezo-actuators, and only comparing results within areas on the order of few ?m{sup 2} unless calibrated directly or compared with in-the-imaged area standards. Diverse materials such as Si, Cr, and photoresist are specifically investigated. This work thereby provides essential insight into the reliable use of MHz vibrations with AFM and provides direct evidence substantiating phenomena such as sensitivity to adhesion, diminished friction for certain ultrasonic conditions, and the particular benefit of UFM and related methods for nanoscale mapping of stiff materials.

  19. Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force

    E-Print Network [OSTI]

    Cui, Yi

    Ultrathin Topological Insulator Bi2Se3 Nanoribbons Exfoliated by Atomic Force Microscopy Seung Sae, Stanford University, Stanford, California 94305 ABSTRACT Ultrathin topological insulator nanostructures), the layered bismuth selenide (Bi2Se3), a single Dirac-cone topological insulator with a large bulk gap, can

  20. Design and analysis of a monolithic flexure atomic force microscope

    E-Print Network [OSTI]

    Ljubicic, Dean M

    2008-01-01T23:59:59.000Z

    This thesis details the design, manufacture, and testing of a sub-nanometer accuracy atomic force microscope. It was made to be integrated into the Sub-Atomic Measuring Machine (SAMM) in collaboration with the University ...

  1. New Atomic Force Microscope Spectroscopy Probes Local Elasticity...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials Characterization New Atomic Force Microscope Spectroscopy Probes Local Elasticity March 04, 2015 Shown is a contact resonance frequency image after nano-oxidation of a...

  2. Sandia National Laboratories: scanning probe microscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    focus on stainless steels. Dr. An is an internationally recognized expert on scanning probe microscopy, such as atomic force microscopy and scanning ... Last Updated:...

  3. Sandia National Laboratories: scanning tunneling microscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    focus on stainless steels. Dr. An is an internationally recognized expert on scanning probe microscopy, such as atomic force microscopy and scanning ... Last Updated:...

  4. Scanning Force Microscopy Studies on Molecular Packing and Friction Anisotropy in Thin Films of

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Scanning Force Microscopy Studies on Molecular Packing and Friction Anisotropy in Thin Films in bulk, was studied using differential scanning calorimetry, optical microscopy, magic angle solid were investigated at the molecular level by a combination of multimode scanning force microscopy (SFM

  5. Long range forces between atomic impurities in liquid helium

    E-Print Network [OSTI]

    Long range forces between atomic impurities in liquid helium J. Dupont-Roc Laboratoire Kastler in a polarizable medium. We show that atomic impurities in liquid helium may indeed realize repulsive forces embedded in liquid helium, super uid or not. Solid helium have also been used. Successful theoretical

  6. Dual harmonic Kelvin probe force microscopy at the graphene–liquid interface

    SciTech Connect (OSTI)

    Collins, Liam; Rodriguez, Brian J., E-mail: brian.rodriguez@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Kilpatrick, Jason I.; Weber, Stefan A. L. [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Vlassiouk, Ivan V. [Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Tselev, Alexander; Jesse, Stephen; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-03-31T23:59:59.000Z

    Kelvin probe force microscopy (KPFM) is a powerful technique for the determination of the contact potential difference (CPD) between an atomic force microscope tip and a sample under ambient and vacuum conditions. However, for many energy storage and conversion systems, including graphene-based electrochemical capacitors, understanding electrochemical phenomena at the solid–liquid interface is paramount. Despite the vast potential to provide fundamental insight for energy storage materials at the nanoscale, KPFM has found limited applicability in liquid environments to date. Here, using dual harmonic (DH)-KPFM, we demonstrate CPD imaging of graphene in liquid. We find good agreement with measurements performed in air, highlighting the potential of DH-KPFM to probe electrochemistry at the graphene–liquid interface.

  7. Atom probe field ion microscopy and related topics: A bibliography 1992

    SciTech Connect (OSTI)

    Russell, K.F.; Godfrey, R.D.; Miller, M.K.

    1993-12-01T23:59:59.000Z

    This bibliography contains citations of books, conference proceedings, journals, and patents published in 1992 on the following types of microscopy: atom probe field ion microscopy (108 items); field emission microscopy (101 items); and field ion microscopy (48 items). An addendum of 34 items missed in previous bibliographies is included.

  8. atomic force acoustic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    systems Peder of Denmark 31 January 2008 12;ii 12;Abstract Within the field of microfluidics and lab-on-a-chip systems 7 3 Mechanical Diode-Based Ultrasonic Atomic Force...

  9. Modeling and control of undesirable dynamics in atomic force microscopes

    E-Print Network [OSTI]

    El Rifai, Osamah M

    2002-01-01T23:59:59.000Z

    The phenomenal resolution and versatility of the atomic force microscope (AFM), has made it a widely-used instrument in nanotechnology. In this thesis, a detailed model of AFM dynamics has been developed. It includes a new ...

  10. ORNL microscopy pencils patterns in polymers at the nanoscale...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (865) 574-7308 ORNL microscopy pencils patterns in polymers at the nanoscale Oak Ridge National Laboratory researchers used atomic force microscopy to draw nanoscale patterns in a...

  11. Alpha-recoil tracks in natural dark mica: Dating geological samples by optical and scanning force microscopy

    E-Print Network [OSTI]

    -differential-interference-contrast microscopy; Scanning force microscopy; Natural radiation damage 1. Introduction Alpha-recoil tracks (ARTsAlpha-recoil tracks in natural dark mica: Dating geological samples by optical and scanning force

  12. A calibration method for lateral forces for use with colloidal probe force microscopy cantilevers

    SciTech Connect (OSTI)

    Quintanilla, M. A. S.; Goddard, D. T. [Nexia Solutions Ltd., Springfields, Salwick, Preston, Lancashire PR4 0XJ (United Kingdom)

    2008-02-15T23:59:59.000Z

    A calibration method is described for colloidal probe cantilevers that enables friction force measurements obtained using lateral force microscopy (LFM) to be quantified. The method is an adaptation of the lever method of Feiler et al. [A. Feiler, P. Attard, and I. Larson, Rev. Sci. Instum. 71, 2746 (2000)] and uses the advantageous positioning of probe particles that are usually offset from the central axis of the cantilever. The main sources of error in the calibration method are assessed, in particular, the potential misalignment of the long axis of the cantilever that ideally should be perpendicular to the photodiode detector. When this is not taken into account, the misalignment is shown to have a significant effect on the cantilever torsional stiffness but not on the lateral photodiode sensitivity. Also, because the friction signal is affected by the topography of the substrate, the method presented is valid only against flat substrates. Two types of particles, 20 {mu}m glass beads and UO{sub 3} agglomerates attached to silicon tapping mode cantilevers were used to test the method against substrates including glass, cleaved mica, and UO{sub 2} single crystals. Comparisons with the lateral compliance method of Cain et al. [R. G. Cain, S. Biggs, and N. W. Page, J. Colloid Interface Sci. 227, 55 (2000)] are also made.

  13. Measurement of Dynamical Forces between Deformable Drops Using the Atomic Force Microscope. I. Theory

    E-Print Network [OSTI]

    Chan, Derek Y C

    effects of electrical double layer repulsion between oil drops charged by adsorbed surfactant mainly to hydrodynamic lubrication forces. 1. Introduction The atomic force microscope (AFM) has long, such as the interaction between rigid probe particles and oil drops1-4 or between a particle and a bubble.5

  14. Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells

    E-Print Network [OSTI]

    Fisher, Frank

    Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells., University of Pittsburgh The most efficient organic solar cell today is made from blending conjugated donors and acceptors in bulk heterojunction organic solar cells. Most microscopic characterization

  15. Using Atom Interferometry to Search for New Forces

    SciTech Connect (OSTI)

    Wacker, Jay G.; /SLAC

    2009-12-11T23:59:59.000Z

    Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10{sup 2} and near-future advances will be able to rewrite the limits for forces with ranges from 100 {micro}m to 1km.

  16. Characterization of Dynamic Surface Processes by Atomic Force Microscopy

    E-Print Network [OSTI]

    Shao, Jingru

    2014-01-01T23:59:59.000Z

    hydrogen terminated as synthesized but may slowly become oxidized to oxygen termi- nated under long time storage

  17. The study of organic crystals by atomic force microscopy

    E-Print Network [OSTI]

    Chow, Ernest Ho Hin

    2014-07-01T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3.10 AFM amplitude profile of ASA (001) under ambient conditions before and after contact with dicalcium phosphate. . . . . . . . 47 4.1 Picture of the Multimode AFM instrument with labelled parts. . 49 4.2 3-D height profile of a standard... List of Abbreviations AN Anthracene ANQ Anthraquinone API Active pharmaceutical ingredient ASA Aspirin ATR Attenuated total reflection BFDH Bravais-Friedel-Donnay-Harker model CSD Cambridge Structural Database DSC Differential scanning calorimetry DPI...

  18. Ultrasonic-Based Mode-Synthesizing Atomic Force Microscopy - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin TransitionProgram |FrankUltrafastHydrogen and FuelInnovation

  19. Workshop on Atomic Force Microscopy, Nanometrology and More | GE Global

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat isJoin the ChallengeHistory

  20. Half-harmonic Kelvin probe force microscopy with transfer function correction

    SciTech Connect (OSTI)

    Guo, Senli [ORNL] [ORNL; Jesse, Stephen [ORNL] [ORNL; Kalinin, Sergei V [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    An approach for surface potential imaging based on half-harmonic band excitation (BE) in Kelvin probe force microscopy is demonstrated. Using linear and half-harmonic BE enables quantitative correction of the cantilever transfer function. Half-harmonic band excitation Kelvin probe force microscopy (HBE KPFM) thus allows quantitative separation of surface potential and topographic contributions to the signal, obviating the primary sources of topographic cross-talk. HBE KPFM imaging and voltage spectroscopy methods are illustrated for several model systems.

  1. Atom probe field ion microscopy and related topics: A bibliography 1989

    SciTech Connect (OSTI)

    Miller, M.K.; Hawkins, A.R.; Russell, K.F.

    1990-12-01T23:59:59.000Z

    This bibliography includes references related to the following topics: atom probe field ion microscopy (APFIM), field ion spectroscopy (FIM), field emission microscopy (FEM), liquid metal ion sources (LMIS), scanning tunneling microscopy (STM), and theory. Technique-orientated studies and applications are included. This bibliography covers the period 1989. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications.

  2. Characterizing absolute piezoelectric microelectromechanical system displacement using an atomic force microscope

    SciTech Connect (OSTI)

    Evans, J., E-mail: radiant@ferrodevices.com; Chapman, S., E-mail: radiant@ferrodevices.com [Radiant Technologies, Inc., 2835C Pan American Fwy NE, Albuquerque, New Mexico 87107 (United States)

    2014-08-14T23:59:59.000Z

    Piezoresponse Force Microscopy (PFM) is a popular tool for the study of ferroelectric and piezoelectric materials at the nanometer level. Progress in the development of piezoelectric MEMS fabrication is highlighting the need to characterize absolute displacement at the nanometer and Ångstrom scales, something Atomic Force Microscopy (AFM) might do but PFM cannot. Absolute displacement is measured by executing a polarization measurement of the ferroelectric or piezoelectric capacitor in question while monitoring the absolute vertical position of the sample surface with a stationary AFM cantilever. Two issues dominate the execution and precision of such a measurement: (1) the small amplitude of the electrical signal from the AFM at the Ångstrom level and (2) calibration of the AFM. The authors have developed a calibration routine and test technique for mitigating the two issues, making it possible to use an atomic force microscope to measure both the movement of a capacitor surface as well as the motion of a micro-machine structure actuated by that capacitor. The theory, procedures, pitfalls, and results of using an AFM for absolute piezoelectric measurement are provided.

  3. Note: Mechanical etching of atomic force microscope tip and microsphere attachment for thermal radiation scattering enhancement

    SciTech Connect (OSTI)

    Brissinger, D.; Parent, G., E-mail: gilles.parent@univ-lorraine.fr; Lacroix, D. [Université de Lorraine, LEMTA, UMR 7563, BP70239, 54500 Vandoeuvre-lés-Nancy (France)] [Université de Lorraine, LEMTA, UMR 7563, BP70239, 54500 Vandoeuvre-lés-Nancy (France)

    2013-12-15T23:59:59.000Z

    This Note describes a mechanical etching technique which can be used to prepare silicon tips used in atomic force microscopy apparatus. For such devices, dedicated tips with specific shapes are now commonly used to probe surfaces. Yet, the control of the tip morphology where characteristic scales are lower than 1 ?m remains a real challenge. Here, we detail a controlled etching process of AFM probes apex allowing micrometer-sized sphere attachment. The technique used and influent parameters are discussed and SEM images of the achieved tips are given. Deceptive problems and drawbacks that might occur during the process are also covered.

  4. A GLRT AND BOOTSTRAP APPROACH TO DETECTION IN MAGNETIC RESONANCE FORCE MICROSCOPY

    E-Print Network [OSTI]

    Moura, José

    A GLRT AND BOOTSTRAP APPROACH TO DETECTION IN MAGNETIC RESONANCE FORCE MICROSCOPY Pei­Jung Chung a model that, although simplistic, captures the features of the problem. We present a GLRT and bootstrap based on the gen- eralized likelihood ratio test (GLRT), and bootstrap. The GLRT is used because besides

  5. Atom probe field ion microscopy and related topics: A bibliography 1990

    SciTech Connect (OSTI)

    Russell, K.F.; Miller, M.K.

    1991-12-01T23:59:59.000Z

    This bibliography includes references related to the following topics: atom probe field ion microscopy (APFIM), field ion microscopy (FIM), field emission (FE), ion sources, and field desorption mass microscopy (FDMM). Technique-orientated studies and applications are included. The bibliography covers the period 1990. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references, listed alphabetically by authors, are subdivided into the categories listed in paragraph one above. An Addendum of references missed in previous bibliographies is included.

  6. High-speed atomic force microscope based on an astigmatic detection system

    SciTech Connect (OSTI)

    Liao, H.-S.; Chen, Y.-H.; Hwu, E.-T.; Chang, C.-S.; Hwang, I.-S., E-mail: ishwang@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Ding, R.-F.; Huang, H.-F.; Wang, W.-M. [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Huang, K.-Y. [Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-10-15T23:59:59.000Z

    High-speed atomic force microscopy (HS-AFM) enables visualizing dynamic behaviors of biological molecules under physiological conditions at a temporal resolution of 1s or shorter. A small cantilever with a high resonance frequency is crucial in increasing the scan speed. However, detecting mechanical resonances of small cantilevers is technically challenging. In this study, we constructed an atomic force microscope using a digital versatile disc (DVD) pickup head to detect cantilever deflections. In addition, a flexure-guided scanner and a sinusoidal scan method were implemented. In this work, we imaged a grating sample in air by using a regular cantilever and a small cantilever with a resonance frequency of 5.5 MHz. Poor tracking was seen at the scan rate of 50 line/s when a cantilever for regular AFM imaging was used. Using a small cantilever at the scan rate of 100 line/s revealed no significant degradation in the topographic images. The results indicate that a smaller cantilever can achieve a higher scan rate and superior force sensitivity. This work shows the potential for using a DVD pickup head in future HS-AFM technology.

  7. Focused ion beam modification of atomic force microscopy tips for near-field scanning optical microscopy

    E-Print Network [OSTI]

    Krogmeier, Jeffrey R.; Dunn, Robert C.

    2001-12-01T23:59:59.000Z

    spatial resolution be- yond the classical diffraction limit.1–3 While the technique can be implemented in several configurations, the most popular utilizes a metal-coated, tapered fiber optic probe to deliver light to nanometric dimensions. Introduced... by Betzig et al. in 1991,2 these metal-coated fiber optic probes have been successfully utilized to study single molecules, thin films, and in limited cases, biological samples.1,3 For the latter, the high spring constant of the fiber optic probes has...

  8. ATOMIC FORCE LITHOGRAPHY OF NANO/MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING OF AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Mendez-Torres, A.; Torres, R.; Lam, P.

    2011-07-15T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  9. ATOMIC FORCE LITHOGRAPHY OF NANO MICROFLUIDIC CHANNELS FOR VERIFICATION AND MONITORING IN AQUEOUS SOLUTIONS

    SciTech Connect (OSTI)

    Torres, R.; Mendez-Torres, A.; Lam, P.

    2011-06-09T23:59:59.000Z

    The growing interest in the physics of fluidic flow in nanoscale channels, as well as the possibility for high sensitive detection of ions and single molecules is driving the development of nanofluidic channels. The enrichment of charged analytes due to electric field-controlled flow and surface charge/dipole interactions along the channel can lead to enhancement of sensitivity and limits-of-detection in sensor instruments. Nuclear material processing, waste remediation, and nuclear non-proliferation applications can greatly benefit from this capability. Atomic force microscopy (AFM) provides a low-cost alternative for the machining of disposable nanochannels. The small AFM tip diameter (< 10 nm) can provide for features at scales restricted in conventional optical and electron-beam lithography. This work presents preliminary results on the fabrication of nano/microfluidic channels on polymer films deposited on quartz substrates by AFM lithography.

  10. Dynamical Casimir–Polder force on a partially dressed atom in a cavity comprising a dielectric

    SciTech Connect (OSTI)

    Yang, H.; Zheng, T.Y., E-mail: zhengty@nenu.edu.cn; Zhang, X.; Shao, X.Q.; Pan, S.M., E-mail: pansm717@nenu.edu.cn

    2014-05-15T23:59:59.000Z

    We put a two-level atom into a cavity comprising a dielectric with output coupling. An analytical expression of the dynamical Casimir–Polder force in such a system is obtained when the system starts from a partially dressed state. And the effects of several relevant parameters of the system on the time-dependent force are also discussed. -- Highlights: •We get the dynamical CP force on a partially dressed atom in a dielectric cavity. •The force in this cavity is larger than that in infinite dielectric space. •The force is not symmetric with respect to the center of the cavity. •The oscillating time of the force increases with the cavity size.

  11. Note: Switching crosstalk on and off in Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Polak, Leo, E-mail: l.polak@vu.nl; Wijngaarden, Rinke J. [Division of Physics and Astronomy, VU University Amsterdam, Amsterdam (Netherlands)] [Division of Physics and Astronomy, VU University Amsterdam, Amsterdam (Netherlands); Man, Sven de [Huygens-Kamerlingh Onnes Laboratorium, Leiden University, Leiden (Netherlands)] [Huygens-Kamerlingh Onnes Laboratorium, Leiden University, Leiden (Netherlands)

    2014-04-15T23:59:59.000Z

    In Kelvin Probe Force Microscopy (KPFM) electronic crosstalk can occur between the excitation signal and probe deflection signal. Here, we demonstrate how a small modification to our commercial instrument enables us to literally switch the crosstalk on and off. We study in detail the effect of crosstalk on open-loop KPFM and compare with closed-loop KPFM. We measure the pure crosstalk signal and verify that we can correct for it in the data-processing required for open-loop KPFM. We also demonstrate that open-loop KPFM results are independent of the frequency and amplitude of the excitation signal, provided that the influence of crosstalk has been eliminated.

  12. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOE Patents [OSTI]

    Campbell, Ann. N. (13170-B Central SE #188, Albuquerque, NM 87123); Anderson, Richard E. (2800 Tennessee NE, Albuquerque, NM 87110); Cole, Jr., Edward I. (2116 White Cloud NE, Albuquerque, NM 87112)

    1995-01-01T23:59:59.000Z

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

  13. Out of equilibrium GigaPa Young modulus of water nanobridge probed by Force Feedback Microscopy

    E-Print Network [OSTI]

    Simon Carpentier; Mario S. Rodrigues; Luca Costa; Miguel V. Vitorino; Elisabeth Charlaix; Joel Chevrier

    2015-03-18T23:59:59.000Z

    Because of capillary condensation, water droplets appear in nano/micropores. The large associated surface interactions can deeply influence macroscopic properties as in granular media. We report that dynamical properties of such nanobridge dramatically change when probed at different time scales. Using a novel AFM mode, the Force Feedback Microscopy, the gap between the nanotip and the surface is continuously varied, and we observe this change in the simultaneous measurements, at different frequencies, of the stiffness G'(N/m), the dissipative coefficient G"(kg/sec) together with the static force. As the measuring time approaches the microsecond, the liquid droplet exhibits a large positive stiffness (it is small and negative in the long time limit). Although clearly controlled by surface effects, it compares to the stiffness of a solid nanobridge with a 1 GigaPa Young modulus. We argue that as evaporation and condensation gradually lose efficiency, the contact line progressively becomes immobile, which explains this behavior.

  14. Out of equilibrium GigaPa Young modulus of water nanobridge probed by Force Feedback Microscopy

    E-Print Network [OSTI]

    Carpentier, Simon; Costa, Luca; Vitorino, Miguel V; Charlaix, Elisabeth; Chevrier, Joel

    2015-01-01T23:59:59.000Z

    Because of capillary condensation, water droplets appear in nano/micropores. The large associated surface interactions can deeply influence macroscopic properties as in granular media. We report that dynamical properties of such nanobridge dramatically change when probed at different time scales. Using a novel AFM mode, the Force Feedback Microscopy, the gap between the nanotip and the surface is continuously varied, and we observe this change in the simultaneous measurements, at different frequencies, of the stiffness G'(N/m), the dissipative coefficient G"(kg/sec) together with the static force. As the measuring time approaches the microsecond, the liquid droplet exhibits a large positive stiffness (it is small and negative in the long time limit). Although clearly controlled by surface effects, it compares to the stiffness of a solid nanobridge with a 1 GigaPa Young modulus. We argue that as evaporation and condensation gradually lose efficiency, the contact line progressively becomes immobile, which expla...

  15. Spatial dependence of polycrystalline FTO’s conductance analyzed by conductive atomic force microscope (C-AFM)

    SciTech Connect (OSTI)

    Peixoto, Alexandre Pessoa; Costa, J. C. da [Department of Electrical Engineering, University of Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, PO Box 4386, Brasília - DF, 70919-970 (Brazil)

    2014-05-15T23:59:59.000Z

    Fluorine-doped Tin oxide (FTO) is a highly transparent, electrically conductive polycrystalline material frequently used as an electrode in organic solar cells and optical-electronic devices [1–2]. In this work a spatial analysis of the conductive behavior of FTO was carried out by Conductive-mode Atomic Force Microscopy (C-AFM). Rare highly oriented grains sample give us an opportunity to analyze the top portion of polycrystalline FTO and compare with the border one. It is shown that the current flow essentially takes place through the polycrystalline edge at grain boundaries.

  16. Mechanistic study of dielectric chemical mechanical polishing by spectral and scaling analysis of atomic force microscope images

    SciTech Connect (OSTI)

    Verhoff, M.L.

    1999-12-22T23:59:59.000Z

    Thermal oxide and PETEOS oxide surfaces, polished on an IPEC 472 with different combinations of polish pad, slurry, and polishing conditions, were studied with ex situ atomic force microscopy. The post polish surfaces were analyzed qualitatively by visual inspection and quantitatively by spectral and scaling analyses. Spectral and scaling analyses gave consistent interpretations of morphology evolution. Polishing with either a fixed abrasive pad or alumina-based slurry occurred via a mechanism for which asperities are removed and recesses are filled. A sputtering-type mechanism may contribute to material removal when polishing with silica- or ceria-based slurries.

  17. Journal of Magnetism and Magnetic Materials 286 (2005) 324328 Light-free magnetic resonance force microscopy for studies of

    E-Print Network [OSTI]

    Journal of Magnetism and Magnetic Materials 286 (2005) 324­328 Light-free magnetic resonance force for Physical Sciences, College Park, MD, USA Available online 4 November 2004 Abstract Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its

  18. Free vibrations of U-shaped atomic force microscope probes

    SciTech Connect (OSTI)

    Rezaei, E.; Turner, J. A., E-mail: jaturner@unl.edu [Mechanical and Materials Engineering, W342 Nebraska Hall, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2014-05-07T23:59:59.000Z

    Contact resonance atomic force microscope (AFM) methods have been used to quantify the elastic and viscoelastic properties of a variety of materials such as polymers, ceramics, biological materials, and metals with spatial resolution on the order of tens of nanometers. This approach involves measurement of the resonant frequencies of the AFM probe both for the free case and the case for which the tip is in contact with a sample. Vibration models of the probe and tip-sample contact models are then used to determine the sample properties from the frequency behavior and to create images of the sample properties. This work has been primarily focused on rectangular, single-beam probes for which the vibration models are relatively simple. Recently, U-shaped AFM probes have been developed to allow local heating of samples and the resonances of these probes are much more complex. In this article, a simplified analytical model of these U-shaped probes is described. This three beam model includes two beams clamped at one end and connected with a perpendicular cross beam at the other end. The beams are assumed only to bend in flexure and twist but their coupling allows a wide range of possible dynamic behavior. Results are presented for the first ten modes and the mode shapes are shown to have complex coupling between the flexure and twisting of the beams, particularly for the higher modes. All resonant frequency results are in good agreement with finite element results for the three probe designs and two values of thickness considered (all wavenumbers are within 3.0%). This work is anticipated to allow U-shaped probes to be used eventually for quantitative measurements of sample material properties during heating using a contact resonance approach.

  19. Fractal properties in fundamental force coupling constants, in atomic energies, and in elementary particle masses

    E-Print Network [OSTI]

    Boris Tatischeff

    2011-04-28T23:59:59.000Z

    Using the discrete-scale invariance theory, we show that the coupling constants of fundamental forces, the atomic masses and energies, and the elementary particle masses, obey to the fractal properties.

  20. Direct determination of the local Hamaker constant of inorganic surfaces based on scanning force microscopy

    SciTech Connect (OSTI)

    Krajina, Brad A.; Kocherlakota, Lakshmi S.; Overney, René M., E-mail: roverney@u.washington.edu [Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750 (United States)

    2014-10-28T23:59:59.000Z

    The energetics involved in the bonding fluctuations between nanometer-sized silicon dioxide (SiO{sub 2}) probes and highly oriented pyrolytic graphite (HOPG) and molybdenum disulfide (MoS{sub 2}) could be quantified directly and locally on the submicron scale via a time-temperature superposition analysis of the lateral forces between scanning force microscopy silicon dioxide probes and inorganic sample surfaces. The so-called “intrinsic friction analysis” (IFA) provided direct access to the Hamaker constants for HOPG and MoS{sub 2}, as well as the control sample, calcium fluoride (CaF{sub 2}). The use of scanning probe enables nanoscopic analysis of bonding fluctuations, thereby overcoming challenges associated with larger scale inhomogeneity and surface roughness common to conventional techniques used to determine surface free energies and dielectric properties. A complementary numerical analysis based on optical and electron energy loss spectroscopy and the Lifshitz quantum electrodynamic theory of van der Waals interactions is provided and confirms quantitatively the IFA results.

  1. Correlation between fundamental binding forces and clinical prognosis...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic force microscopy was used to “fish” for binding reactions between a fibronectin-coated probe (i.e., substrate simulating an implant device) and each of 15...

  2. Polarizable Atomic Multipole-Based AMOEBA Force Field for Proteins Jiajing Zhang,

    E-Print Network [OSTI]

    Ponder, Jay

    Polarizable Atomic Multipole-Based AMOEBA Force Field for Proteins Yue Shi, Zhen Xia, Jiajing Zhang is presented. The current version (AMOEBA- 2013) utilizes permanent electrostatic multipole moments through- ments. The atomic multipole electrostatic parameters for each amino acid residue type are derived from

  3. Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Phil Attard

    E-Print Network [OSTI]

    Attard, Phil

    Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Microscope Phil. Adhesion Sci. Technol. 16, 753­791 (2002).) Running title: Friction, Adhesion, and Deformation Abstract for the friction force microscope, quantitative measurements of friction and the ef- fect of adhesion, measurement

  4. Potential variations around grain boundaries in impurity-doped BaSi? epitaxial films evaluated by Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Tsukahara, D.; Baba, M.; Honda, S.; Toko, K. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Imai, Y. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); AIST, Tsukuba, Ibaraki 305-8565 (Japan); Hara, K. O.; Usami, N. [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Japan Science and Technology Agency, CREST, Chiyoda, Tokyo 102-0075 (Japan); Werner, J. H. [Institute for Photovoltaics, University of Stuttgart, Stuttgart 70569 (Germany); Suemasu, T. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Japan Science and Technology Agency, CREST, Chiyoda, Tokyo 102-0075 (Japan); Institute for Photovoltaics, University of Stuttgart, Stuttgart 70569 (Germany)

    2014-09-28T23:59:59.000Z

    Potential variations around the grain boundaries (GBs) in antimony (Sb)-doped n-type and boron (B)-doped p-type BaSi? epitaxial films on Si(111) were evaluated by Kelvin probe force microscopy. Sb-doped n-BaSi? films exhibited positively charged GBs with a downward band bending at the GBs. The average barrier height for holes was approximately 10 meV for an electron concentration n ? 10¹? cm?³. This downward band bending changed to upward band bending when n was increased to n = 1.8 × 10¹?cm?³. In the B-doped p-BaSi? films, the upward band bending was observed for a hole concentration p ? 10¹?cm?³. The average barrier height for electrons decreased from approximately 25 to 15 meV when p was increased from p = 2.7 × 10¹? to p = 4.0 × 10¹? cm?³. These results are explained under the assumption that the position of the Fermi level E{sub f} at GBs depends on the degree of occupancy of defect states at the GBs, while E{sub f} approached the bottom of the conduction band or the top of the valence band in the BaSi? grain interiors with increasing impurity concentrations. In both cases, such small barrier heights may not deteriorate the carrier transport properties. The electronic structures of impurity-doped BaSi? are also discussed using first-principles pseudopotential method to discuss the insertion sites of impurity atoms and clarify the reason for the observed n-type conduction in the Sb-doped BaSi? and p-type conduction in the B-doped BaSi?.

  5. Measurements of dispersion forces between colloidal latex particles with the atomic force microscope and comparison with Lifshitz theory

    SciTech Connect (OSTI)

    Elzbieciak-Wodka, Magdalena; Ruiz-Cabello, F. Javier Montes; Trefalt, Gregor; Maroni, Plinio; Borkovec, Michal, E-mail: michal.borkovec@unige.ch [Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1205 Geneva (Switzerland)] [Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, 30, Quai Ernest-Ansermet, 1205 Geneva (Switzerland); Popescu, Mihail N. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)] [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2014-03-14T23:59:59.000Z

    Interaction forces between carboxylate colloidal latex particles of about 2 ?m in diameter immersed in aqueous solutions of monovalent salts were measured with the colloidal probe technique, which is based on the atomic force microscope. We have systematically varied the ionic strength, the type of salt, and also the surface charge densities of the particles through changes in the solution pH. Based on these measurements, we have accurately measured the dispersion forces acting between the particles and estimated the apparent Hamaker constant to be (2.0 ± 0.5) × 10{sup ?21} J at a separation distance of about 10 nm. This value is basically independent of the salt concentration and the type of salt. Good agreement with Lifshitz theory is found when roughness effects are taken into account. The combination of retardation and roughness effects reduces the value of the apparent Hamaker constant and its ionic strength dependence with respect to the case of ideally smooth surfaces.

  6. Force microscopy of layering and friction in an ionic liquid Judith Hotha,b

    E-Print Network [OSTI]

    Mueser, Martin

    shape of the force vs. distance curve is explained by a model for the interaction between tip, gold of the compliant force sensor between branches of the oscillatory force curve. Frictional force between-viscosity, yet load- bearing lubricant [1-4]. The load-bearing ability stems from the formation of solvation

  7. QED Corrections to the Electromagnetic Abraham Force. Casimir Momentum of the Hydrogen atom?

    E-Print Network [OSTI]

    Bart Van Tiggelen; Sebastien Kawka; Geert L. J. A. Rikken

    2012-02-23T23:59:59.000Z

    We develop a QED approach to find the contribution of the quantum vacuum to the electromagnetic Abraham force. Semi-classical theories predict diverging contributions from the quantum vacuum. We show that the divergencies disappear by Kramers-Bethe mass-renormalization. The finite remainder is compared to the relativistic corrections to the Abraham force. This work generalizes an earlier paper [1], dedicated to the harmonic oscillator, to the hydrogen atom and corrects two subtle errors.

  8. Atomic force microscope with combined FTIR-Raman spectroscopy having a micro thermal analyzer

    SciTech Connect (OSTI)

    Fink, Samuel D. (Aiken, SC); Fondeur, Fernando F. (North Augusta, SC)

    2011-10-18T23:59:59.000Z

    An atomic force microscope is provided that includes a micro thermal analyzer with a tip. The micro thermal analyzer is configured for obtaining topographical data from a sample. A raman spectrometer is included and is configured for use in obtaining chemical data from the sample.

  9. Apparatus for imaging liquid and dielectric materials with scanning polarization force microscopy

    DOE Patents [OSTI]

    Hu, Jun (Berkeley, CA); Ogletree, D. Frank (El Cerrito, CA); Salmeron, Miguel (El Cerrito, CA); Xiao, Xudong (Kowloon, CN)

    1998-01-01T23:59:59.000Z

    The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

  10. Method for imaging liquid and dielectric materials with scanning polarization force microscopy

    DOE Patents [OSTI]

    Hu, Jun (Berkeley, CA); Ogletree, D. Frank (El Cerrito, CA); Salmeron, Miguel (El Cerrito, CA); Xiao, Xudong (Kowloon, CN)

    1999-01-01T23:59:59.000Z

    The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

  11. Characteristics of cooperative spontaneous radiation with applications to atom microscopy and coherent XUV radiation generation

    E-Print Network [OSTI]

    Chang, Juntao

    2009-05-15T23:59:59.000Z

    quicker than single atom decay, with a decay rate proportional to N(?/R)2, where N is the atom numbers, R is the size of the atom cloud, and ? is the wavelength. We call it Markovian regime because the sytem does not persist memory effect. The other regime...

  12. Method and apparatus for differential spectroscopic atomic-imaging using scanning tunneling microscopy

    DOE Patents [OSTI]

    Kazmerski, Lawrence L. (Lakewood, CO)

    1990-01-01T23:59:59.000Z

    A Method and apparatus for differential spectroscopic atomic-imaging is disclosed for spatial resolution and imaging for display not only individual atoms on a sample surface, but also bonding and the specific atomic species in such bond. The apparatus includes a scanning tunneling microscope (STM) that is modified to include photon biasing, preferably a tuneable laser, modulating electronic surface biasing for the sample, and temperature biasing, preferably a vibration-free refrigerated sample mounting stage. Computer control and data processing and visual display components are also included. The method includes modulating the electronic bias voltage with and without selected photon wavelengths and frequency biasing under a stabilizing (usually cold) bias temperature to detect bonding and specific atomic species in the bonds as the STM rasters the sample. This data is processed along with atomic spatial topography data obtained from the STM raster scan to create a real-time visual image of the atoms on the sample surface.

  13. Effect of Roughness as Determined by Atomic Force Microscopy on the Wetting Properties of PTFE Thin

    E-Print Network [OSTI]

    Drelich, Jaroslaw W.

    Engineering College of Mines and Earth Sciences University of Utah Salt Lake City, Utah 84112 and G. YAMAUCHI decreases the spreading of a non-wetting liquid on low energy solids (1­4). Similar work with high energy ratio (r a/A (da/dA) 1), a is the apparent contact angle, a is the actual area of surface

  14. Single asperity tribochemical wear of silicon nitride studied by atomic force microscopy

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    are hard, inert, and stable at high temperatures, making them attractive for use in extreme en- vironments lubrication, which results in low fric- tion and almost no wear, has been observed on sufficiently smooth of conditions. In the AFM geometry, the tip serves as an idealized single asperity interacting with a nearly

  15. Reactivity of Ozone with Solid Potassium Iodide Investigated by Atomic Force Microscopy

    E-Print Network [OSTI]

    Brown, Matthew A.

    2008-01-01T23:59:59.000Z

    J. C. , Reactivity of ozone on solid potassium iodide.and mechanisms of aqueous ozone reactions with bromide,for Dry Deposition of Ozone to Seawater Surfaces. Journal of

  16. CREATE-IGERT Trainees (Cont.) Patrick O'Dell Atomic force microscopy to

    E-Print Network [OSTI]

    California at Davis, University of

    and plant cell wall synthesis for biofuels Tracy Zeng ­ Cell wall formation and fermentation processes Hyrum Gillespie ­ Engineering vector-borne viral citrus disease resistance Tiffany Glavan ­ Transgenic

  17. Structural Characterization of Micromechanical Properties in Asphalt Using Atomic Force Microscopy

    E-Print Network [OSTI]

    Allen, Robert Grover

    2012-02-14T23:59:59.000Z

    -nuclear aromatics and hetero-aromatic molecules (asphaltenes), viscous naphtheno-aromatic hydrocarbons (heavy oils) and heterocyclic and polar compounds (resins). The initial relative amount and arrangement of 9 asphaltenes, resins and oils are highly... between the PDM morphology and the colloidal system where the asphaltenes are stabilized by polar aromatics in a sea of naphthene aromatics and saturated compounds. This does not necessarily invalidate the model but suggests that it is possibly too...

  18. Observation of Changes in Bacterial Cell Morphology Using Tapping Mode Atomic Force Microscopy

    E-Print Network [OSTI]

    sodium salt (MOPS) buffer (as a control), and the surface topography of the cells was examined after. Topographic images, phase images, traces of surface topography, and analyses of surface roughness were the topography of the cell was altered by the different treatments. The surface roughness was quantified in terms

  19. Preamplifying cantilevers for dynamic atomic force microscopy Benedikt Zeyen,1,a

    E-Print Network [OSTI]

    of periodic interactions between the probe and the substrate when the laser is aligned on the paddle for measurements on periodically poled lithium niobate ferroelectric material is presented. A comparison

  20. Parallel Atomic Force Microscopy and NMR Spectroscopy To Investigate Self-Assembled Protein-Nucleotide Aggregates

    E-Print Network [OSTI]

    Dellaire, Graham

    - tially be quite useful for a wide variety of systems, since it would allow for the linkage of mesoscale

  1. Mode-synthesizing atomic force microscopy and mode-synthesizing sensing

    SciTech Connect (OSTI)

    Passain, Ali; Thundat, Thomas George; Tetard, Laurene

    2014-07-22T23:59:59.000Z

    A method of analyzing a sample that includes applying a first set of energies at a first set of frequencies to a sample and applying, simultaneously with the applying the first set of energies, a second set of energies at a second set of frequencies, wherein the first set of energies and the second set of energies form a multi-mode coupling. The method further includes detecting an effect of the multi-mode coupling.

  2. Mechanical and Electrical Properties of CdTe Tetrapods Studied by Atomic Force Microscopy

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    J.B. Li, L.W. Wang, A.P. Alivisatos, Nature 430 (2004) 190-Meisel, E.C. Scher, A.P. Alivisatos, Nature Materials 2 [16]Tanaka, K. Sivula, A.P. Alivisatos, J.M.J. Frechet, Journal

  3. Atomic Force Microscopy of Photosystem II and Its Unit Cell Clustering Quantitatively Delineate the Mesoscale

    E-Print Network [OSTI]

    Geissler, Phillip

    the Mesoscale Variability in Arabidopsis Thylakoids Bibiana Onoa1 , Anna R. Schneider2 , Matthew D. Brooks3 Quantitatively Delineate the Mesoscale Variability in Arabidopsis Thylakoids. PLoS ONE 9(7): e101470. doi:10

  4. Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 3) : a scanning tunneling microscopy study.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 × 3) : a scanning tunneling of the atomic and electronic structure of graphene monolayer islands on the 6H-SiC(0001)(3×3) (SiC(3×3)) surface reconstruction using scanning tunneling microscopy (STM) and spectroscopy (STS). The orientation of the graphene

  5. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    SciTech Connect (OSTI)

    Shur, V. Ya., E-mail: vladimir.shur@urfu.ru; Zelenovskiy, P. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

    2014-08-14T23:59:59.000Z

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  6. Atomic Forces from Electronic Energies Via the Hellmann-Feynman Theorem, with Application to Semiconductor (110) Surface Relaxation

    E-Print Network [OSTI]

    SANKEY, OF; Allen, Roland E.

    1986-01-01T23:59:59.000Z

    to be the dominant force on a surface As atom and that it acts per- pendicular (noncentral) to the bonding direction between the two surface atoms. From the calculations of Sec. IV, we find this force in GaAs (atom 1 is As) to be + 0.71 eV/A, while the recursion... method for n =2 yields + 0.03 eV/A and for n =4 yields + 0.33 eV/A. Similar indirect interactions have been previously noted between ada- toms. ' To include these multiatom effects at a surface, we have to consider a finite slab exactly...

  7. Sensing Current and Forces with SPM

    SciTech Connect (OSTI)

    Park, Jeong Y.; Maier, Sabine; Hendriksen, Bas; Salmeron, Miquel

    2010-07-02T23:59:59.000Z

    Atomic force microscopy (AFM) and scanning tunneling microscopy (STM) are well established techniques to image surfaces and to probe material properties at the atomic and molecular scale. In this review, we show hybrid combinations of AFM and STM that bring together the best of two worlds: the simultaneous detection of atomic scale forces and conduction properties. We illustrate with several examples how the detection of forces during STM and the detection of currents during AFM can give valuable additional information of the nanoscale material properties.

  8. Sub-surface characterization and three dimensional profiling of semiconductors by magnetic resonance force microscopy

    SciTech Connect (OSTI)

    Hammel, P.C.; Moore, G.; Roukes, M.; Zhenyong Zhang

    1996-10-01T23:59:59.000Z

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project successfully developed a magnetic resonance force microscope (MRFM) instrument to mechanically detect magnetic resonance signals. This technique provides an intrinsically subsurface, chemical-species-specific probe of structure, constituent density and other properties of materials. As in conventional magnetic resonance imaging (MRI), an applied magnetic field gradient selects a well defined volume of the sample for study. However mechanical detection allows much greater sensitivity, and this in turn allows the reduction of the size of the minimum resolvable volume. This requires building an instrument designed to achieve nanometer-scale resolution at buried semiconductor interfaces. High-resolution, three-dimensional depth profiling of semiconductors is critical in the development and fabrication of semiconductor devices. Currently, there is no capability for direct, high-resolution observation and characterization of dopant density, and other critical features of semiconductors. The successful development of MRFM in conjunction with modifications to improve resolution will enable for the first time detailed structural and electronic studies in doped semiconductors and multilayered nanoelectronic devices, greatly accelerating the current pace of research and development.

  9. Method for measurement of friction forces on single cells in microfluidic devices

    E-Print Network [OSTI]

    Ma, Hongshen

    both dry and wet conditions, are well estab- lished.16,17 The measurement of friction at micrometer the friction between dry microscopic surfaces, including atomic force microscopy, fric- tion-force microscopyMethod for measurement of friction forces on single cells in microfluidic devices Lazar

  10. Optimal experimental design for the detection of light atoms from high-resolution scanning transmission electron microscopy images

    SciTech Connect (OSTI)

    Gonnissen, J.; De Backer, A.; Martinez, G. T.; Van Aert, S., E-mail: Sandra.VanAert@uantwerpen.be [Electron Microscopy for Materials Science, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Dekker, A. J. den [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Delft Center for Systems and Control, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Rosenauer, A. [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee NW1, 28359 Bremen (Germany); Sijbers, J. [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2014-08-11T23:59:59.000Z

    We report an innovative method to explore the optimal experimental settings to detect light atoms from scanning transmission electron microscopy (STEM) images. Since light elements play a key role in many technologically important materials, such as lithium-battery devices or hydrogen storage applications, much effort has been made to optimize the STEM technique in order to detect light elements. Therefore, classical performance criteria, such as contrast or signal-to-noise ratio, are often discussed hereby aiming at improvements of the direct visual interpretability. However, when images are interpreted quantitatively, one needs an alternative criterion, which we derive based on statistical detection theory. Using realistic simulations of technologically important materials, we demonstrate the benefits of the proposed method and compare the results with existing approaches.

  11. Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Microscopy and Field Evaporation Simulation

    SciTech Connect (OSTI)

    Devaraj, Arun; Colby, Robert J.; Vurpillot, F.; Thevuthasan, Suntharampillai

    2014-03-26T23:59:59.000Z

    Metal-dielectric composite materials, specifically metal nanoparticles supported on or embedded in metal oxides, are widely used in catalysis. The accurate optimization of such nanostructures warrants the need for detailed three-dimensional characterization. Atom probe tomography is uniquely capable of generating sub-nanometer structural and compositional data with part-per-million mass sensitivity, but there are reconstruction artifacts for composites containing materials with strongly differing fields of evaporation, as for oxide-supported metal nanoparticles. By correlating atom probe tomography with scanning transmission electron microscopy for Au nanoparticles embedded in an MgO support, deviations from an ideal topography during evaporation are demonstrated directly, and correlated with compositional errors in the reconstructed data. Finite element simulations of the field evaporation process confirm that protruding Au nanoparticles will evolve on the tip surface, and that evaporation field variations lead to an inaccurate assessment of the local composition, effectively lowering the spatial resolution of the final reconstructed dataset. Cross-correlating the experimental data with simulations results in a more detailed understanding of local evaporation aberrations during APT analysis of metal-oxide composites, paving the way towards a more accurate three-dimensional characterization of this technologically important class of materials.

  12. In situ atomic force microscope study of high-temperature untwinning surface relief in Mn-Fe-Cu antiferromagnetic shape memory alloy

    SciTech Connect (OSTI)

    Wang, L.; Cui, Y. G.; Wan, J. F.; Rong, Y. H.; Zhang, J. H.; Jin, X.; Cai, M. M. [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)] [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-05-06T23:59:59.000Z

    The N-type untwinning surface relief associated with the fcc {r_reversible} fct martensitic transformation (MT) was observed in the Mn{sub 81.5}Fe{sub 14.0}Cu{sub 4.5} antiferromagnetic high-temperature shape memory alloy (SMA) by in situ atomic force microscopy. The measured untwinning relief angles ({theta}{sub {alpha}} Double-Vertical-Line {theta}{sub {beta}}) at the ridge and at the valley were different, and both angles were less than the conventional values. The surface relief exhibited good reversibility during heating and cooling because of the crystallographic reversibility of thermal-elastic SMAs. Untwinning shear was proposed as the main mechanism of the N-type surface relief. The order of the reverse MT was discussed based on the experimental measurements.

  13. Scanning probe microscopy studies of semiconductor surfaces

    SciTech Connect (OSTI)

    Weinberg, W.H. [Univ. of California, Santa Barbara, CA (United States)

    1996-10-01T23:59:59.000Z

    Recent work involving atomic force microscopy and scanning tunneling microscopy is discussed which involves strain-induced, self-assembling nanostructures in compound semiconductor materials. Specific examples include one-dimensional quantum wires of InAs grown by MBE on GaAs(001) and zero-dimensional quantum dots of InP grown by MOCVD on InGaP which is lattice matched to GaAs(001).

  14. Energy shift and Casimir-Polder force for an atom out of thermal equilibrium near a dielectric substrate

    E-Print Network [OSTI]

    Wenting Zhou; Hongwei Yu

    2014-09-07T23:59:59.000Z

    We study the energy shift and the Casimir-Polder force of an atom out of thermal equilibrium near the surface of a dielectric substrate. We first generalize, adopting the local source hypothesis, the formalism proposed by Dalibard, Dupont-Roc and Cohen-Tannoudji, which separates the contributions of thermal fluctuations and radiation reaction to the energy shift and allows a distinct treatment to atoms in the ground and excited states, to the case out of thermal equilibrium, and then use the generalized formalism to calculate the energy shift and the Casimir-Polder force of an isotropically polarizable neutral atom. We identify the effects of the thermal fluctuations that originate from the substrate and the environment and discuss in detail how the Casimir-Polder force out of thermal equilibrium behaves in three different distance regions in both the low-temperature limit and the high-temperature limit for both the ground-state and excited-state atoms, with special attention devoted to the new features as opposed to thermal equilibrium. In particular, we recover the new behavior of the atom-wall force out of thermal equilibrium at large distances in the low temperature limit recently found in a different theoretical framework and furthermore we give a concrete region where this behavior holds.

  15. Optical, ferroelectric, and piezoresponse force microscopy studies of pulsed laser deposited Aurivillius Bi?FeTi?O?? thin films

    SciTech Connect (OSTI)

    Kooriyattil, Sudheendran [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States); Department of Physics, Sree Kerala Varma College, Thrissur-680011, Kerala (India); Pavunny, Shojan P., E-mail: rkatiyar@uprrp.edu, E-mail: shojanpp@gmail.com; Barrionuevo, Danilo; Katiyar, Ram S., E-mail: rkatiyar@uprrp.edu, E-mail: shojanpp@gmail.com [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States)

    2014-10-14T23:59:59.000Z

    Bi?FeTi?O?? (BFTO) based Aurivillius ferroelectric thin films were fabricated on strontium ruthanate coated amorphous fused silica substrates using pulsed laser deposition technique. Optical, ferroelectric, and piezoresponse properties of these thin films were investigated. The estimated refractive index (n) and extinction coefficient (k) for these films were in the range from 2.40 to 2.59 and 0.012 to 0.19, respectively. The bandgap of the BFTO thin layers was estimated to be 2.88 eV. Domain switching and hysteresis loops of BFTO films were studied utilizing piezoresponse force microscopy (PFM). The measured apparent polarization (P{sub r}) and coercive field (E{sub c}) for the samples were 20 ?C/cm² and 250 kV/cm, respectively. The amplitude and phase hysteresis curves obtained from PFM characterization reveal that these films can be switched below 5 V. These results suggest that BFTO in thin film form is a promising material for photo ferroelectric and optoelectronic devices applications.

  16. Abstract--Automation has long been recognized as an im-portant goal in AFM (Atomic Force Microscope) nanomanipu-

    E-Print Network [OSTI]

    Southern California, University of

    Abstract--Automation has long been recognized as an im- portant goal in AFM (Atomic Force on the order of 10 nm, however, automation has re- mained an elusive goal, primarily because of the spatial multi-tip arrays) or by automating the manipulation process, thus bypassing the time-consuming and labor

  17. SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography and silicon epitaxial-regrowth

    E-Print Network [OSTI]

    Rokhinson, Leonid

    SiGe quantum dot single-hole transistor fabricated by atomic force microscope nanolithography; published online 10 November 2006 A SiGe quantum dot single-hole transistor passivated by silicon epitaxial are reproducible, in sharp contrast with the noisy and irreproducible I-V characteristics of unpassivated SiGe

  18. Nanocrystalline Ni-3.6 at.% P and its transformation sequence studied by atom-probe field-ion microscopy

    SciTech Connect (OSTI)

    Hentschel, T.; Isheim, D.; Kirchheim, R.; Mueller, F.; Kreye, H.

    2000-02-25T23:59:59.000Z

    The transformation sequence of electroless plated nanocrystalline Ni-3.6 at.% P layers upon different heat treatments is studied by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and atom-probe field-ion microscopy (APFIM). APFIM reveals P segregation at the grain boundaries in the as-plated nanocrystalline alloy. DSC shows two heat releases upon isochronic heat treatment. During the first heat release, starting at about 136 C for a heating rate of 20 C/min, structural relaxation occurs first, followed by slight crystal growth and segregation enhancement, as shown by XRD and APFIM. Nucleation of the equilibrium phase Ni{sub 3}P starts in the transition to the second heat release. This second heat release, with a sharp onset at 417 C for heating at a rate of 20 C/min, is related to the major part of Ni{sub 3}P-phase formation and substantial grain growth. The transformation sequence is compared with the one observed on amorphous Ni-P alloys and discussed in terms of a thermodynamic model.

  19. Microscopy image segmentation tool: Robust image data analysis

    SciTech Connect (OSTI)

    Valmianski, Ilya, E-mail: ivalmian@ucsd.edu; Monton, Carlos; Schuller, Ivan K. [Department of Physics and Center for Advanced Nanoscience, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)] [Department of Physics and Center for Advanced Nanoscience, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States)

    2014-03-15T23:59:59.000Z

    We present a software package called Microscopy Image Segmentation Tool (MIST). MIST is designed for analysis of microscopy images which contain large collections of small regions of interest (ROIs). Originally developed for analysis of porous anodic alumina scanning electron images, MIST capabilities have been expanded to allow use in a large variety of problems including analysis of biological tissue, inorganic and organic film grain structure, as well as nano- and meso-scopic structures. MIST provides a robust segmentation algorithm for the ROIs, includes many useful analysis capabilities, and is highly flexible allowing incorporation of specialized user developed analysis. We describe the unique advantages MIST has over existing analysis software. In addition, we present a number of diverse applications to scanning electron microscopy, atomic force microscopy, magnetic force microscopy, scanning tunneling microscopy, and fluorescent confocal laser scanning microscopy.

  20. The unification of the fundamental interaction within Maxwell electromagnetism: Model of hydrogen atom. Gravity as the secondary electric force. Calculation of the unified inertia force

    E-Print Network [OSTI]

    L. Neslusan

    2010-12-28T23:59:59.000Z

    Considering two static, electrically charged, elementary particles, we demonstrate a possible way of proving that all known fundamental forces in the nature are the manifestations of the single, unique interaction. We re-define the gauging of integration constants in the Schwarzschild solution of Einstein field equations. We consider the potential energy in this context regardless it is gravitational or electric potential energy. With the newly gauged constants, we sketch how the unique interaction can be described with the help of an appropriate solution of the well-known Maxwell equations. According the solution, there are two zones, in the system of two oppositely charged particles, where the force is oscillating. The first particle can be in a stable, constant distance from the second particle, between the neighbouring regions of repulsion and attraction. In an outer oscillation zone, the corresponding energy levels in the proton-electron systems are identical (on the level of accuracy of values calculated by the Dirac's equations) to some experimentally determined levels in the hydrogen atom. For each system of two particles, there is also the zone with the macroscopic, i.e. monotonous behavior of the force. As well, the solution can be used to demonstrate that the net force between two assemblies consisting each (or at least one) of the same numbers of both positively and negatively charged particles is never zero. A secondary electric force, having the same orientation as the primary electric force between the oppositely charged particles, is always present. It can be identified to the gravity. Finally, the solution of the Maxwell equations can be used to calculate the inertia force of a particle. The consistent formulas for both acting and inertia forces enable to construct the dimensionless (without gravitational constant, permitivity of vacuum, etc.) equation of motion.

  1. Detection of erythrocytes influenced by aging and type 2 diabetes using atomic force microscope

    SciTech Connect (OSTI)

    Jin, Hua; Xing, Xiaobo [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Zhao, Hongxia [Chemistry Department, Jinan University, Guangzhou 510632 (China) [Chemistry Department, Jinan University, Guangzhou 510632 (China); Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510090 (China); Chen, Yong [Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031 (China)] [Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031 (China); Huang, Xun [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Ma, Shuyuan [Chemistry Department, Jinan University, Guangzhou 510632 (China) [Chemistry Department, Jinan University, Guangzhou 510632 (China); The First Affiliated Hospital, Jinan University, Guangzhou 510632 (China); Ye, Hongyan [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China); Cai, Jiye, E-mail: tjycai@jnu.edu.cn [Chemistry Department, Jinan University, Guangzhou 510632 (China)] [Chemistry Department, Jinan University, Guangzhou 510632 (China)

    2010-01-22T23:59:59.000Z

    The pathophysiological changes of erythrocytes are detected at the molecular scale, which is important to reveal the onset of diseases. Type 2 diabetes is an age-related metabolic disorder with high prevalence in elderly (or old) people. Up to now, there are no treatments to cure diabetes. Therefore, early detection and the ability to monitor the progression of type 2 diabetes are very important for developing effective therapies. Type 2 diabetes is associated with high blood glucose in the context of insulin resistance and relative insulin deficiency. These abnormalities may disturb the architecture and functions of erythrocytes at molecular scale. In this study, the aging- and diabetes-induced changes in morphological and biomechanical properties of erythrocytes are clearly characterized at nanometer scale using atomic force microscope (AFM). The structural information and mechanical properties of the cell surface membranes of erythrocytes are very important indicators for determining the healthy, diseased or aging status. So, AFM may potentially be developed into a powerful tool in diagnosing diseases.

  2. Isolating and moving single atoms using silicon nanocrystals

    DOE Patents [OSTI]

    Carroll, Malcolm S. (Albuquerque, NM)

    2010-09-07T23:59:59.000Z

    A method is disclosed for isolating single atoms of an atomic species of interest by locating the atoms within silicon nanocrystals. This can be done by implanting, on the average, a single atom of the atomic species of interest into each nanocrystal, and then measuring an electrical charge distribution on the nanocrystals with scanning capacitance microscopy (SCM) or electrostatic force microscopy (EFM) to identify and select those nanocrystals having exactly one atom of the atomic species of interest therein. The nanocrystals with the single atom of the atomic species of interest therein can be sorted and moved using an atomic force microscope (AFM) tip. The method is useful for forming nanoscale electronic and optical devices including quantum computers and single-photon light sources.

  3. A high-pressure atomic force microscope for imaging in supercritical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in-situ atomic scale imaging of a calcite...

  4. A variable-temperature nanostencil compatible with a low-temperature scanning tunneling microscope/atomic force microscope

    SciTech Connect (OSTI)

    Steurer, Wolfram, E-mail: wst@zurich.ibm.com; Gross, Leo; Schlittler, Reto R.; Meyer, Gerhard [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)] [IBM Research-Zurich, 8803 Rüschlikon (Switzerland)

    2014-02-15T23:59:59.000Z

    We describe a nanostencil lithography tool capable of operating at variable temperatures down to 30 K. The setup is compatible with a combined low-temperature scanning tunneling microscope/atomic force microscope located within the same ultra-high-vacuum apparatus. The lateral movement capability of the mask allows the patterning of complex structures. To demonstrate operational functionality of the tool and estimate temperature drift and blurring, we fabricated LiF and NaCl nanostructures on Cu(111) at 77 K.

  5. Probing Nanostructures for Photovoltaics: Using atomic force microscopy and other tools to characterize nanoscale materials for harvesting solar energy

    E-Print Network [OSTI]

    Zaniewski, Anna Monro

    2012-01-01T23:59:59.000Z

    v List of Tables vii 1 Introduction 1.1 Photovoltaicsand J. V. Manca. Prog. Photovoltaics Res. Appl. , 15:713,polymer blends. Prog. Photovoltaics Res. Appl. , 15:727,

  6. NANOMETER-SCALE INVESTIGATIONS BY ATOMIC FORCE MICROSCOPY INTO THE EFFECT OF DIFFERENT TREATMENTS ON THE SURFACE STRUCTURE OF HAIR

    E-Print Network [OSTI]

    Durkan, C.; Wang, N.

    2014-09-15T23:59:59.000Z

    that the CPD between the hair and the cantilever was 0.4-0.6 V. In Figs. 4(a) and (b), we show the topography and KPFM images of a small area, and in Fig. 4(c), the surface potential (in colour) is overlaid on the 3-d topography. It is known that the surface... in the topography and the potential map, it is also a possibility that it is the deposits themselves that possess a lower surface potential than the hair surface they are on, and that this is where the overall negative charge on hair originates. A cross...

  7. Probing Nanostructures for Photovoltaics: Using atomic force microscopy and other tools to characterize nanoscale materials for harvesting solar energy

    E-Print Network [OSTI]

    Zaniewski, Anna Monro

    2012-01-01T23:59:59.000Z

    for harvesting solar energy by Anna Monro Zaniewski Amaterials for harvesting solar energy Copyright 2012 by Annafor harvesting solar energy by Anna Monro Zaniewski Doctor

  8. Fabrication of Ti/TiOx tunneling barriers by tapping mode atomic force microscopy induced local oxidation

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    through thin 5 nm titanium films using the very local electric field between the tip and the sample the chamber is filled with pure nitrogen bubbling through deionised water. By mixing dry and humid nitrogen

  9. Novel approaches to investigate behaviors of bacteria by atomic force microscopy and circulating tumor cells through microfluidics

    E-Print Network [OSTI]

    Gray, David Steven

    2014-01-01T23:59:59.000Z

    The adaptability and apparent ingenuity of renegade and intruding cells within the human body present formidable challenges in warding off disease. As the longevity of humans increases, cancer will afflict greater numbers, ...

  10. Probing Nanostructures for Photovoltaics: Using atomic force microscopy and other tools to characterize nanoscale materials for harvesting solar energy

    E-Print Network [OSTI]

    Zaniewski, Anna Monro

    2012-01-01T23:59:59.000Z

    is called the short circuit current. The value of thecircuit voltage and short circuit current. The fill factorvoltage (V OC ), short circuit current (I SC ) and ?ll

  11. Probing Nanostructures for Photovoltaics: Using atomic force microscopy and other tools to characterize nanoscale materials for harvesting solar energy

    E-Print Network [OSTI]

    Zaniewski, Anna Monro

    2012-01-01T23:59:59.000Z

    output” means the power output of the solar cell with theof a solar cell is de?ned by [46]: max power output sunlightsolar cell for various values of an applied voltage. This is equivalent to measuring the power output

  12. In-situ and ex-situ observations of lithium de-intercalation from LiCoO? : atomic force microscopy and transmission electron microscopy studies

    E-Print Network [OSTI]

    Clémençon, Anne

    2005-01-01T23:59:59.000Z

    Lithium cobalt dioxide is the most commonly used material for positive electrodes in lithium rechargeable batteries. During lithium de-intercalation from this material, ... undergoes a number of phase transitions, which ...

  13. Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution

    SciTech Connect (OSTI)

    Karc?, Özgür [NanoMagnetics Instruments Ltd., Hacettepe - ?vedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Department of Nanotechnology and Nanomedicine, Hacettepe University, Beytepe, 06800 Ankara (Turkey); Dede, Münir [NanoMagnetics Instruments Ltd., Hacettepe - ?vedik OSB Teknokent, 1368. Cad., No: 61/33, 06370, Yenimahalle, Ankara (Turkey); Oral, Ahmet, E-mail: orahmet@metu.edu.tr [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15T23:59:59.000Z

    We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be ?12 fm/?Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system.

  14. Direct observation of fatigue in epitaxially grown Pb(Zr,Ti)O3 thin films using second harmonic piezoresponse force microscopy

    SciTech Connect (OSTI)

    Murari, Nishit M [University of Puerto Rico; Hong, Seungbum [Argonne National Laboratory (ANL); Lee, Ho Nyung [ORNL; Katiyar, Ram S. [University of Puerto Rico

    2011-01-01T23:59:59.000Z

    Here, we present a direct observation of fatigue phenomena in epitaxially grown Pb(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} (PZT) thin films using second harmonic piezoresponse force microscopy (SH-PFM). We observed strong correlation between the SH-PFM amplitude and phase signals with the remnant piezoresponse at different switching cycles. The SH-PFM results indicate that the average fraction of switchable domains decreases globally and the phase delays of polarization switching differ locally. In addition, we found that the fatigue developed uniformly over the whole area without developing region-by-region suppression of switchable polarization as in polycrystalline PZT thin films.

  15. Probing graphene defects and estimating graphene quality with optical microscopy

    SciTech Connect (OSTI)

    Lai, Shen [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); Kyu Jang, Sung [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Jae Song, Young, E-mail: yjsong@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Department of Physics, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Lee, Sungjoo, E-mail: leesj@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of)

    2014-01-27T23:59:59.000Z

    We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality.

  16. The ReactorSTM: Atomically resolved scanning tunneling microscopy under high-pressure, high-temperature catalytic reaction conditions

    SciTech Connect (OSTI)

    Herbschleb, C. T.; Tuijn, P. C. van der; Roobol, S. B.; Navarro, V.; Bakker, J. W.; Liu, Q.; Stoltz, D.; Cañas-Ventura, M. E.; Verdoes, G.; Spronsen, M. A. van; Bergman, M.; Crama, L.; Taminiau, I.; Frenken, J. W. M., E-mail: frenken@physics.leidenuniv.nl [Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. box 9504, 2300 RA Leiden (Netherlands); Ofitserov, A.; Baarle, G. J. C. van [Leiden Probe Microscopy B.V., J.H. Oortweg 21, 2333 CH Leiden (Netherlands)

    2014-08-15T23:59:59.000Z

    To enable atomic-scale observations of model catalysts under conditions approaching those used by the chemical industry, we have developed a second generation, high-pressure, high-temperature scanning tunneling microscope (STM): the ReactorSTM. It consists of a compact STM scanner, of which the tip extends into a 0.5 ml reactor flow-cell, that is housed in a ultra-high vacuum (UHV) system. The STM can be operated from UHV to 6 bars and from room temperature up to 600 K. A gas mixing and analysis system optimized for fast response times allows us to directly correlate the surface structure observed by STM with reactivity measurements from a mass spectrometer. The in situ STM experiments can be combined with ex situ UHV sample preparation and analysis techniques, including ion bombardment, thin film deposition, low-energy electron diffraction and x-ray photoelectron spectroscopy. The performance of the instrument is demonstrated by atomically resolved images of Au(111) and atom-row resolution on Pt(110), both under high-pressure and high-temperature conditions.

  17. The extended wedge method: Atomic force microscope friction calibration for improved tolerance to instrument misalignments, tip offset, and blunt probes

    SciTech Connect (OSTI)

    Khare, H. S.; Burris, D. L. [126 Spencer Laboratory, Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716 (United States)

    2013-05-15T23:59:59.000Z

    One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS{sub 2} to demonstrate the technique. Carbon and single crystal MoS{sub 2} had friction coefficients of {mu}= 0.20 {+-} 0.04 and {mu}= 0.006 {+-} 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS{sub 2} had a friction coefficient of {mu}= 0.005 {+-} 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).

  18. Electron Microscopy | Center for Functional Nanomaterials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Capabilities Atomic-resolution imaging of internal materials structure with scanning transmission and transmission electron microscopy Spectroscopic characterization with...

  19. Signatures of hydrophobic collapse in extended proteins captured with force spectroscopy

    E-Print Network [OSTI]

    Fernandez, Julio M.

    of the different driving forces in protein folding. atomic force microscopy molecular dynamics protein folding chemicals. Protein folding probed under these conditions has revealed two-state folding for many small to each other. It is widely accepted that, under such conditions, protein folding is driven mostly

  20. Graphene thickness dependent adhesion force and its correlation to surface roughness

    SciTech Connect (OSTI)

    Pourzand, Hoorad [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Tabib-Azar, Massood, E-mail: azar.m@utah.edu [Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Biomedical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

    2014-04-28T23:59:59.000Z

    In this paper, adhesion force of graphene layers on 300?nm silicon oxide is studied. A simple model for measuring adhesion force for a flat surface with sub-nanometer roughness was developed and is shown that small surface roughness decreases adhesion force while large roughness results in an effectively larger adhesion forces. We also show that surface roughness over scales comparable to the tip radius increase by nearly a factor of two, the effective adhesion force measured by the atomic force microscopy. Thus, we demonstrate that surface roughness is an important parameter that should be taken into account in analyzing the adhesion force measurement results.

  1. A pressure gauge based on gas density measurement from analysis of the thermal noise of an atomic force microscope cantilever

    SciTech Connect (OSTI)

    Seo, Dongjin; Ducker, William A. [Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Paul, Mark R. [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2012-05-15T23:59:59.000Z

    We describe a gas-density gauge based on the analysis of the thermally-driven fluctuations of an atomic force microscope (AFM) cantilever. The fluctuations are modeled as a ring-down of a simple harmonic oscillator, which allows fitting of the resonance frequency and damping of the cantilever, which in turn yields the gas density. The pressure is obtained from the density using the known equation of state. In the range 10-220 kPa, the pressure readings from the cantilever gauge deviate by an average of only about 5% from pressure readings on a commercial gauge. The theoretical description we use to determine the pressure from the cantilever motion is based upon the continuum hypothesis, which sets a minimum pressure for our analysis. It is anticipated that the cantilever gauge could be extended to measure lower pressures given a molecular theoretical description. Alternatively, the gauge could be calibrated for use in the non-continuum range. Our measurement technique is similar to previous AFM cantilever measurements, but the analysis produces improved accuracy.

  2. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller

    SciTech Connect (OSTI)

    Habibullah, H., E-mail: h.habib@student.adfa.edu.au; Pota, H. R., E-mail: h.pota@adfa.edu.au; Petersen, I. R., E-mail: i.petersen@adfa.edu.au [School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory 2612 (Australia)

    2014-03-15T23:59:59.000Z

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM’s piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.

  3. Scanning probe microscopy: Sulfate minerals in scales and cements

    SciTech Connect (OSTI)

    Hall, C. [Schlumberger Cambridge Research (United Kingdom)

    1995-11-01T23:59:59.000Z

    The principles of scanning probe microscopy (SPM) are illustrated with examples from oilfield mineralogy, particularly emphasizing sulfate minerals involved in scale formation and cement hydration chemistry. The topography of the (010) cleavage surface of gypsum observed by atomic force microscopy shows atomically flat terraces separated by shallow steps often only one unit cell high. SPM allows direct observation of processes on mineral surfaces while they are in contact with solutions. The dissolution etching and crystal growth of gypsum and barite are discussed and rates of step migration estimated. The orientation of steps is related to the crystallographic axes. The action of phosphonate crystal growth inhibitor on gypsum and of a chelating scale solvent on barite are also shown. The multiphase microstructure of an oilwell cement clinker is described in relation to its hydration chemistry in contact with water and its reaction with sulfate ions.

  4. Velocity tuning of friction with two trapped atoms

    E-Print Network [OSTI]

    Gangloff, Dorian; Counts, Ian; Jhe, Wonho; Vuleti?, Vladan

    2015-01-01T23:59:59.000Z

    Friction is the basic, ubiquitous mechanical interaction between two surfaces that results in resistance to motion and energy dissipation. In spite of its technological and economic significance, our ability to control friction remains modest, and our understanding of the microscopic processes incomplete. At the atomic scale, mismatch between the two contacting crystal lattices can lead to a reduction of stick-slip friction (structural lubricity), while thermally activated atomic motion can give rise to a complex velocity dependence, and nearly vanishing friction at sufficiently low velocities (thermal lubricity). Atomic force microscopy has provided a wealth of experimental results, but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a full quantitative description from first principles. Here, using an ion-crystal friction emulator with single-atom, single substrate-site spatial resolution and single-slip temporal resolution, we measure the friction force...

  5. EMSL - Microscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    microscopy Capability Details * Electron microscopes with tomography, cryo, scanning, photoemission and high-resolution (sub-nanometer) imaging capabilities* Focused ion beam...

  6. Probing Atomic Structure and Majorana Wavefunctions in Mono-Atomic Fe-chains on Superconducting Pb-Surface

    E-Print Network [OSTI]

    Pawlak, Remy; Klinovaja, Jelena; Meier, Tobias; Kawai, Shigeki; Glatzel, Thilo; Loss, Daniel; Meyer, Ernst

    2015-01-01T23:59:59.000Z

    Motivated by the striking promise of quantum computation, Majorana bound states (MBSs) in solid-state systems have attracted wide attention in recent years. In particular, the wavefunction localization of MBSs is a key feature and crucial for their future implementation as qubits. Here, we investigate the spatial and electronic characteristics of topological superconducting chains of iron atoms on the surface of Pb(110) by combining scanning tunneling microscopy (STM) and atomic force microscopy (AFM). We demonstrate that the Fe chains are mono-atomic, structured in a linear fashion, and exhibit zero-bias conductance peaks at their ends which we interprete as signature for a Majorana bound state. Spatially resolved conductance maps of the atomic chains reveal that the MBSs are well localized at the chain ends (below 25 nm), with two localization lengths as predicted by theory. Our observation lends strong support to use MBSs in Fe chains as qubits for quantum computing devices.

  7. Time-dependent mechanical behavior of newly developing matrix of bovine primary chondrocytes and bone marrow stromal cells using Atomic Force Microscopy

    E-Print Network [OSTI]

    Lee, BoBae

    2009-01-01T23:59:59.000Z

    Introduction: Articular cartilage chondrocytes are solely responsible for the synthesis, assembly, and maintenance of the extracellular matrix (ECM) and yet occupy <10% of the cartilage tissue volume. Chondrocytes (equilibrium ...

  8. Structural Evolution and Alignment of Cylinder-Forming PS-b-PEP Thin Films in Confinement Studied by Time-Lapse Atomic Force Microscopy

    E-Print Network [OSTI]

    Sibener, Steven

    ultimately lead to the essentially perfect alignment of cylindrical microdomains. INTRODUCTION The generation in trough 30 cylinders on crest 1 µm Figure 1. AFM image showing macroscopic alignment of in-plane cylindrical copolymer microdomains. In the thin film region, copolymers align inside nanochannels, whereas

  9. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    E-Print Network [OSTI]

    Koffas, Telly Stelianos

    2004-01-01T23:59:59.000Z

    polystyrene exposed to toluene vapor, and polystyrenethe case of polystyrene exposed to toluene. 26 Toluene is ainterface, (b) polystyrene exposed to toluene vapor, and (c)

  10. Mapping out the structural changes of natural and pretreated plant cell wall surfaces by atomic force microscopy single molecular recognition imaging

    E-Print Network [OSTI]

    Zhang, Mengmeng; Chen, Guojun; Kumar, Rajeev; Xu, Bingqian

    2013-01-01T23:59:59.000Z

    Biochem J 2. Solomon BD: Biofuels and sustainability. Ecolplants and enzymes for biofuels production. Science 2007,of lignocellulose. Biofuels Bioprod Biorefin 2012, 11. Yang

  11. Photoresponse properties of large-area MoS{sub 2} atomic layer synthesized by vapor phase deposition

    SciTech Connect (OSTI)

    Luo, Siwei; Qi, Xiang, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn; Ren, Long; Hao, Guolin; Fan, Yinping; Liu, Yundan; Han, Weijia; Zang, Chen; Li, Jun; Zhong, Jianxin, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, People's Republic of China Laboratory for Quantum Engineering and Micro-Nano Energy Technology, and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan 411105 (China)

    2014-10-28T23:59:59.000Z

    Photoresponse properties of a large area MoS{sub 2} atomic layer synthesized by vapor phase deposition method without any catalyst are studied. Scanning electron microscopy, atomic force microscopy, Raman spectrum, and photoluminescence spectrum characterizations confirm that the two-dimensional microstructures of MoS{sub 2} atomic layer are of high quality. Photoelectrical results indicate that the as-prepared MoS{sub 2} devices have an excellent sensitivity and a good reproducibility as a photodetector, which is proposed to be ascribed to the potential-assisted charge separation mechanism.

  12. Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling Microscopy and Spectroscopy

    E-Print Network [OSTI]

    Kim, Sehun

    Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling ReceiVed: June 26, 2010 Graphene was epitaxially grown on a 6H-SiC(0001) substrate by thermal the evolution of the graphene growth as a function of the temperature. We found that the evaporation of Si

  13. Atomic-Scale Spin-Polarized Scanning Tunneling Microscopy Applied To Mn3N2(010) Haiqiang Yang and Arthur R. Smith

    E-Print Network [OSTI]

    source effusion cell for Mn and a rf plasma source for N [5,6]. All STM imaging is performed at 300 K-centered tetragonal (fct) rock-salt type struc- ture. The bulk magnetic moments of the Mn atoms are FM within (001

  14. Nanoscale Electromechanics of Ferroelectric and Biological Systems: A New Dimension in Scanning Probe Microscopy

    SciTech Connect (OSTI)

    Kalinin, Sergei V [ORNL; Rodriguez, Brian J [ORNL; Jesse, Stephen [ORNL; Karapetian, Edgar [ORNL; Mirman, B [Suffolk University, Boston; Eliseev, E. A. [National Academy of Science of Ukraine, Kiev, Ukraine; Morozovska, A. N. [National Academy of Science of Ukraine, Kiev, Ukraine

    2007-01-01T23:59:59.000Z

    Functionality of biological and inorganic systems ranging from nonvolatile computer memories and microelectromechanical systems to electromotor proteins and cellular membranes is ultimately based on the intricate coupling between electrical and mechanical phenomena. In the past decade, piezoresponse force microscopy (PFM) has been established as a powerful tool for nanoscale imaging, spectroscopy, and manipulation of ferroelectric and piezoelectric materials. Here, we give an overview of the fundamental image formation mechanism in PFM and summarize recent theoretical and technological advances. In particular, we show that the signal formation in PFM is complementary to that in the scanning tunneling microscopy (STM) and atomic force microscopy (AFM) techniques, and we discuss the implications. We also consider the prospect of extending PFM beyond ferroelectric characterization for quantitative probing of electromechanical behavior in molecular and biological systems and high-resolution probing of static and dynamic polarization switching processes in low-dimensional ferroelectric materials and heterostructures.

  15. Microscopy | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    By Atom Probe Tomography. 14YWT oxide dispersion strengthened (ODS) ferritic steel was irradiated with of 5 MeV Ni2+ ions, at 300 °C, 450 °C, and 600 °......

  16. Bridging the pressure gap: In situ atomic-level investigations of model platinum catalyst surfaces under reaction conditions by scanning tunneling microscopy

    SciTech Connect (OSTI)

    McIntyre, B.J.

    1994-05-01T23:59:59.000Z

    Results of this thesis show that STM measurements can provide information about the surfaces and their adsorbates. Stability of Pt(110) under high pressures of H2, O2, and CO was studied (Chap. 4). In situ UHV and high vacuum experiments were carried out for sulfur on Pt(111) (Chap.5). STM studies of CO/S/Pt(111) in high CO pressures showed that the Pt substrate undergoes a stacking-fault-domain reconstruction involving periodic transitions from fcc to hcp stacking of top-layer atoms (Chap.6). In Chap.7, the stability of propylene on Pt(111) and the decomposition products were studied in situ with the HPSTM. Finally, in Chap.8, results are presented which show how the Pt tip of the HPSTM was used to locally rehydrogenate and oxidize carbonaceous clusters deposited on the Pt(111) surface; the Pt tip acted as a catalyst after activation by short voltage pulses.

  17. Scanning Transmission Electron Microscopy for Nanostructure

    E-Print Network [OSTI]

    Pennycook, Steve

    152 6 Scanning Transmission Electron Microscopy for Nanostructure Characterization S. J. Pennycook. Introduction The scanning transmission electron microscope (STEM) is an invaluable tool atom. The STEM works on the same principle as the normal scanning electron microscope (SEM), by forming

  18. Optical Microscopy and 4Optical Microscopy and 4 Pi MicroscopyPi Microscopy

    E-Print Network [OSTI]

    La Rosa, Andres H.

    Optical Microscopy and 4Optical Microscopy and 4 Pi MicroscopyPi Microscopy Carolyn A. SuttonCarolyn A. Sutton PH 464PH 464 #12;OverviewOverview The OpticalThe Optical MicroscopeMicroscopy 4 Pi Microscopy4 Pi Microscopy Optical Microscope for Metallography #12;Optical Microscope: OriginsOptical

  19. Electron Microscopy Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electron Microscopy Center Argonne Home > EMC > EMC Home Electron Microscopy Center Web Site has moved This page has moved to http:www.anl.govcnmgroupelectron-microscopy-cente...

  20. Growth mode evolution of hafnium oxide by atomic layer deposition

    SciTech Connect (OSTI)

    Nie, Xianglong; Ma, Fei; Ma, Dayan, E-mail: madayan@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi (China); Xu, Kewei [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, People's Republic of China and Department of Physics and Opt-electronic Engineering, Xi'an University of Arts and Science, Xi'an 710065, Shaanxi (China)

    2014-01-15T23:59:59.000Z

    HfO{sub 2} thin films were deposited using tetrakis-ethylmethylamido hafnium and H{sub 2}O as precursors on silicon by atomic layer deposition (ALD). The morphology and microstructures at different ALD cycles were characterized by atomic force microscopy and high-resolution transmission electron microscopy. Based on the height–height correlation function and power spectral density function, quantitative analysis of surface morphologies was performed. Three characteristic dimensions (?{sub 1}, ?{sub 2}, and ?{sub 3}) corresponding to three surface structures, islands, local and global fluctuations, were identified. The evolution of ALD growth mode at range of the three critical scales was investigated, respectively. It suggests the transformation of growth mode from quasi two-dimensional layer-by-layer to three-dimensional island for global fluctuations.

  1. Directly correlated transmission electron microscopy and atom...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    well-separated oxides (NiAl2O4) precipitated along grain boundaries in the metal. Aluminum was depleted from the grain boundary between oxides and also from one side of the...

  2. Surface forces: Surface roughness in theory and experiment

    SciTech Connect (OSTI)

    Parsons, Drew F., E-mail: Drew.Parsons@anu.edu.au; Walsh, Rick B.; Craig, Vincent S. J. [Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)] [Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2014-04-28T23:59:59.000Z

    A method of incorporating surface roughness into theoretical calculations of surface forces is presented. The model contains two chief elements. First, surface roughness is represented as a probability distribution of surface heights around an average surface height. A roughness-averaged force is determined by taking an average of the classic flat-surface force, weighing all possible separation distances against the probability distributions of surface heights. Second the model adds a repulsive contact force due to the elastic contact of asperities. We derive a simple analytic expression for the contact force. The general impact of roughness is to amplify the long range behaviour of noncontact (DLVO) forces. The impact of the elastic contact force is to provide a repulsive wall which is felt at a separation between surfaces that scales with the root-mean-square (RMS) roughness of the surfaces. The model therefore provides a means of distinguishing between “true zero,” where the separation between the average centres of each surface is zero, and “apparent zero,” defined by the onset of the repulsive contact wall. A normal distribution may be assumed for the surface probability distribution, characterised by the RMS roughness measured by atomic force microscopy (AFM). Alternatively the probability distribution may be defined by the histogram of heights measured by AFM. Both methods of treating surface roughness are compared against the classic smooth surface calculation and experimental AFM measurement.

  3. In-situ scanning probe microscopy of electrodeposited nickel.

    SciTech Connect (OSTI)

    Kelly, James J.; Dibble, Dean C.

    2004-10-01T23:59:59.000Z

    The performance characteristics and material properties such as stress, microstructure, and composition of nickel coatings and electroformed components can be controlled over a wide range by the addition of small amounts of surface-active compounds to the electroplating bath. Saccharin is one compound that is widely utilized for its ability to reduce tensile stress and refine grain size in electrodeposited nickel. While the effects of saccharin on nickel electrodeposition have been studied by many authors in the past, there is still uncertainty over saccharin's mechanisms of incorporation, stress reduction, and grain refinement. In-situ scanning probe microscopy (SPM) is a tool that can be used to directly image the nucleation and growth of thin nickel films at nanometer length scales to help elucidate saccharin's role in the development and evolution of grain structure. In this study, in-situ atomic force microscopy (AFM) and scanning tunneling microscopy (STM) techniques are used to investigate the effects of saccharin on the morphological evolution of thin nickel films. By observing mono-atomic height nickel island growth with and without saccharin present we conclude that saccharin has little effect on the nickel surface mobility during deposition at low overpotentials where the growth occurs in a layer-by-layer mode. Saccharin was imaged on Au(l11) terraces as condensed patches without resolved packing structure. AFM measurements of the roughness evolution of nickel films up to 1200 nm thick on polycrystalline gold indicate that saccharin initially increases the roughness and surface skewness of the deposit that at greater thickness becomes smoother than films deposited without saccharin. Faceting of the deposit morphology decreases as saccharin concentration increases even for the thinnest films that have 3-D growth.

  4. Distance dependence of the phase signal in eddy current microscopy

    E-Print Network [OSTI]

    Roll, Tino; Fischer, Ulrich; Schleberger, Marika

    2008-01-01T23:59:59.000Z

    Atomic force microscopy using a magnetic tip is a promising tool for investigating conductivity on the nano-scale. By the oscillating magnetic tip eddy currents are induced in the conducting parts of the sample which can be detected in the phase signal of the cantilever. However, the origin of the phase signal is still controversial because theoretical calculations using a monopole appoximation for taking the electromagnetic forces acting on the tip into account yield an effect which is too small by more than two orders of magnitude. In order to determine the origin of the signal we used especially prepared gold nano patterns embedded in a non-conducting polycarbonate matrix and measured the distance dependence of the phase signal. Our data clearly shows that the interacting forces are long ranged and therefore, are likely due to the electromagnetic interaction between the magnetic tip and the conducting parts of the surface. Due to the long range character of the interaction a change in conductivity of $\\Del...

  5. Nanometer-scale electrochemical patterning of LiMn2O4 surfaces by an atomic force microscope operating in air

    SciTech Connect (OSTI)

    Kostecki, Robert; Bonhomme, Frederic; Servant, Laurent; Argoul, Francoise; McLarnon, Frank

    2001-06-22T23:59:59.000Z

    Electrochemical nanometer-scale patterning of the surface of a conducting lithium manganese oxide (LiMn{sub 2}O{sub 4}) by scanning probe microscopy (SPM) was studied. The ability to produce nanometer-size patterns of chemically modified oxide or nanometer-sized alterations of the oxide morphology is demonstrated and discussed with reference to possible mechanisms. It is demonstrated that unlike the SPM-based surface oxidation of metals and semiconductors, the LiMn{sub 2}O{sub 4} surface is altered via electrochemically generated species. We show that a localized surface chemical change can be confined to a depth which depends on the oxide-tip voltage difference and ambient humidity. In situ Raman microscopy measurements of localized electrochemical reaction products suggest complex mechanisms of processes induced at the LiMn{sub 2}O{sub 4} surface, such as delithiation through Li-proton exchange and disproportionation of LiMn{sub 2}O{sub 4} to MnO{sub 2} and soluble Mn{sup 2+} species.

  6. Ultrafast scanning tunneling microscopy

    SciTech Connect (OSTI)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01T23:59:59.000Z

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  7. Multimode laser cooling and ultra-high sensitivity force sensing with nanowires

    E-Print Network [OSTI]

    Hosseini, Mahdi; Slatyer, Harri J; Buchler, Ben C; Lam, Ping Koy

    2015-01-01T23:59:59.000Z

    Photo-induced forces can be used to manipulate and cool the mechanical motion of oscillators. When the oscillator is used as a force sensor, such as in atomic force microscopy, active feedback is an enticing route to enhancing measurement performance. Here, we show broadband multimode cooling of $-23$ dB down to a temperature of $8 \\pm 1$~K in the stationary regime. Through the use of periodic quiescence feedback cooling, we show improved signal-to-noise ratios for the measurement of transient signals. We compare the performance of real feedback to numerical post-processing of data and show that both methods produce similar improvements to the signal-to-noise ratio of force measurements. We achieved a room temperature force measurement sensitivity of $< 2\\times10^{-16}$ N with integration time of less than $0.1$ ms. The high precision and fast force microscopy results presented will potentially benefit applications in biosensing, molecular metrology, subsurface imaging and accelerometry.

  8. Climate forcing Climate forcing

    E-Print Network [OSTI]

    MacKinnon, Jennifer

    parameters (solar distance factors) solar luminosity moon orbit volcanoes and other geothermal sources,000 years (large panels) and since 1750 (inset panels). Measurements are shown from ice cores (symbols forcings are shown on the right hand axes of the large panels. {Figure 6.4} !"#$#%&'(!&#)$&*$+#$,-.$/0

  9. SARA M. HASHMI, Ph.D. Yale University School of Engineering & Applied Science Tel: 203-745-6414; Fax: 203-432-4387

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    : Microfluidic device design & fabrication; Optical microscopy & Image analysis; Atomic Force Microscopy

  10. Metal atomization spray nozzle

    DOE Patents [OSTI]

    Huxford, T.J.

    1993-11-16T23:59:59.000Z

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  11. atom probe study: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    using both APT and correlative microscopy techniques, a more complete understanding... Bennett, Samantha 2011-02-08 2 ATOM-PROBE TOMOGRAPHIC STUDY OF THE THREE-DIMENSIONAL...

  12. In Situ Adsorption Studies at the Solid/Liquid Interface: Characterization of Biological Surfaces and Interfaces Using Sum Frequency Generation Vibrational Spectroscopy, Atomic Force Microscopy, and Quartz Crystal Microbalance

    E-Print Network [OSTI]

    Phillips, D.C.

    2006-01-01T23:59:59.000Z

    ii 3 Adsorption Studies of a Model Amphiphilic Peptide onMicrobalance Studies of LK 14 Adsorption on Hydrophobic andQCM Adsorption Studies . . . . . . . . .

  13. Frontiers of in situ electron microscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

    2015-01-01T23:59:59.000Z

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore »this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

  14. Atomic Resolution Imaging and Quantification of Chemical Functionality of Surfaces

    SciTech Connect (OSTI)

    Schwarz, Udo [Yale University

    2014-12-10T23:59:59.000Z

    The work carried out from 2006-2014 under DoE support was targeted at developing new approaches to the atomic-scale characterization of surfaces that include species-selective imaging and an ability to quantify chemical surface interactions with site-specific accuracy. The newly established methods were subsequently applied to gain insight into the local chemical interactions that govern the catalytic properties of model catalysts of interest to DoE. The foundation of our work was the development of three-dimensional atomic force microscopy (3D-AFM), a new measurement mode that allows the mapping of the complete surface force and energy fields with picometer resolution in space (x, y, and z) and piconewton/millielectron volts in force/energy. From this experimental platform, we further expanded by adding the simultaneous recording of tunneling current (3D-AFM/STM) using chemically well-defined tips. Through comparison with simulations, we were able to achieve precise quantification and assignment of local chemical interactions to exact positions within the lattice. During the course of the project, the novel techniques were applied to surface-oxidized copper, titanium dioxide, and silicon oxide. On these materials, defect-induced changes to the chemical surface reactivity and electronic charge density were characterized with site-specific accuracy.

  15. Profile for Arun Tej Mallajosyula

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electron Microscopy, Transmission Electron Microscopy, and Atomic Force Microscopy. Device Characterization: Current - Voltage Measurement with Microprobe Station and Solar...

  16. MATERIALS WITH COMPLEX ELECTRONIC/ATOMIC STRUCTURES

    SciTech Connect (OSTI)

    D. M. PARKIN; L. CHEN; ET AL

    2000-09-01T23:59:59.000Z

    We explored both experimentally and theoretically the behavior of materials at stresses close to their theoretical strength. This involves the preparation of ultra fine scale structures by a variety of fabrication methods. In the past year work has concentrated on wire drawing of in situ composites such as Cu-Ag and Cu-Nb. Materials were also fabricated by melting alloys in glass and drawing them into filaments at high temperatures by a method known as Taylor wire technique. Cu-Ag microwires have been drawn by this technique to produce wires 10 {micro}m in diameter that consist of nanoscale grains of supersaturated solid solution. Organogels formed from novel organic gelators containing cholesterol tethered to squaraine dyes or trans-stilbene derivatives have been studied from several different perspectives. The two types of molecules are active toward several organic liquids, gelling in some cases at w/w percentages as low as 0.1. While relatively robust, acroscopically dry gels are formed in several cases, studies with a variety of probes indicate that much of the solvent may exist in domains that are essentially liquid-like in terms of their microenvironment. The gels have been imaged by atomic force microscopy and conventional and fluorescence microscopy, monitoring both the gelator fluorescence in the case of the stilbene-cholesterol gels and, the fluorescence of solutes dissolved in the solvent. Remarkably, our findings show that several of the gels are composed of similarly appearing fibrous structures visible at the nano-, micro-, and macroscale.

  17. Photothermal imaging scanning microscopy

    DOE Patents [OSTI]

    Chinn, Diane (Pleasanton, CA); Stolz, Christopher J. (Lathrop, CA); Wu, Zhouling (Pleasanton, CA); Huber, Robert (Discovery Bay, CA); Weinzapfel, Carolyn (Tracy, CA)

    2006-07-11T23:59:59.000Z

    Photothermal Imaging Scanning Microscopy produces a rapid, thermal-based, non-destructive characterization apparatus. Also, a photothermal characterization method of surface and subsurface features includes micron and nanoscale spatial resolution of meter-sized optical materials.

  18. Phase modulated multiphoton microscopy

    E-Print Network [OSTI]

    Karki, Khadga Jung; Pullerits, Tonu

    2015-01-01T23:59:59.000Z

    We show that the modulation of the phases of the laser beams of ultra-short pulses leads to modulation of the two photon fluorescence intensity. The phase modulation technique when used in multi-photon microscopy can improve the signal to noise ratio. The technique can also be used in multiplexing the signals in the frequency domain in multi-focal raster scanning microscopy. As the technique avoids the use of array detectors as well as elaborate spatiotemporal multiplexing schemes it provides a convenient means to multi-focal scanning in axial direction. We show examples of such uses. Similar methodology can be used in other non-linear scanning microscopies, such as second or third harmonic generation microscopy.

  19. Spectroscopic imaging in electron microscopy

    SciTech Connect (OSTI)

    Pennycook, Stephen J [ORNL; Colliex, C. [Universite Paris Sud, Orsay, France

    2012-01-01T23:59:59.000Z

    In the scanning transmission electron microscope, multiple signals can be simultaneously collected, including the transmitted and scattered electron signals (bright field and annular dark field or Z-contrast images), along with spectroscopic signals such as inelastically scattered electrons and emitted photons. In the last few years, the successful development of aberration correctors for the electron microscope has transformed the field of electron microscopy, opening up new possibilities for correlating structure to functionality. Aberration correction not only allows for enhanced structural resolution with incident probes into the sub-angstrom range, but can also provide greater probe currents to facilitate mapping of intrinsically weak spectroscopic signals at the nanoscale or even the atomic level. In this issue of MRS Bulletin, we illustrate the power of the new generation of electron microscopes with a combination of imaging and spectroscopy. We show the mapping of elemental distributions at atomic resolution and also the mapping of electronic and optical properties at unprecedented spatial resolution, with applications ranging from graphene to plasmonic nanostructures, and oxide interfaces to biology.

  20. Computational microscopy for sample analysis

    E-Print Network [OSTI]

    Ikoma, Hayato

    2014-01-01T23:59:59.000Z

    Computational microscopy is an emerging technology which extends the capabilities of optical microscopy with the help of computation. One of the notable example is super resolution fluorescence microscopy which achieves ...

  1. Nonlinear vibrational microscopy

    DOE Patents [OSTI]

    Holtom, Gary R. (Richland, WA); Xie, Xiaoliang Sunney (Richland, WA); Zumbusch, Andreas (Munchen, DE)

    2000-01-01T23:59:59.000Z

    The present invention is a method and apparatus for microscopic vibrational imaging using coherent Anti-Stokes Raman Scattering or Sum Frequency Generation. Microscopic imaging with a vibrational spectroscopic contrast is achieved by generating signals in a nonlinear optical process and spatially resolved detection of the signals. The spatial resolution is attained by minimizing the spot size of the optical interrogation beams on the sample. Minimizing the spot size relies upon a. directing at least two substantially co-axial laser beams (interrogation beams) through a microscope objective providing a focal spot on the sample; b. collecting a signal beam together with a residual beam from the at least two co-axial laser beams after passing through the sample; c. removing the residual beam; and d. detecting the signal beam thereby creating said pixel. The method has significantly higher spatial resolution then IR microscopy and higher sensitivity than spontaneous Raman microscopy with much lower average excitation powers. CARS and SFG microscopy does not rely on the presence of fluorophores, but retains the resolution and three-dimensional sectioning capability of confocal and two-photon fluorescence microscopy. Complementary to these techniques, CARS and SFG microscopy provides a contrast mechanism based on vibrational spectroscopy. This vibrational contrast mechanism, combined with an unprecedented high sensitivity at a tolerable laser power level, provides a new approach for microscopic investigations of chemical and biological samples.

  2. Magnetic nanowire based high resolution magnetic force microscope probes

    E-Print Network [OSTI]

    Qin, Lu-Chang

    -resolution magnetic force microscope probes using preformed magnetic nanowires. Nickel and cobalt nanowires produced by electrodeposition were directly assembled onto the tip of a commercial atomic force microscope cantilever

  3. Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-08-26T23:59:59.000Z

    Establishes requirements for management and operation of the DOE Protective Force (PF), establishes requirements for firearms operations and defines the firearms courses of fire. Cancels: DOE M 473.2-1A DOE M 473.2-2

  4. Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-03-07T23:59:59.000Z

    The manual establishes requirements for management and operation of the DOE Protective Force, establishes requirements for firearms operations and defines the firearms courses of fire. Chg 1 dated 3/7/06. DOE M 470.4-3A cancels DOE M 470.4-3, Chg 1, Protective Force, dated 3-7-06, Attachment 2, Contractor Requirement Document (CRD) only (except for Section C). Chg 1, dated 3-7-06, cancels DOE M 470.4-3

  5. Casimir forces

    E-Print Network [OSTI]

    S. Reynaud; A. Lambrecht

    2014-10-10T23:59:59.000Z

    The present notes are organized as the lectures given at the Les Houches Summer School "Quantum Optics and Nanophotonics" in August 2013. The first section contains an introduction and a description of the current state-of-the-art for Casimir force measurements and their comparison with theory. The second and third sections are a pedagogical presentation of the main features of the theory of Casimir forces for 1-dimensional model systems and for mirrors in 3-dimensional space.

  6. Ultrafast pump-probe force microscopy with nanoscale resolution

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    Cerullo, “Confocal ultrafast pump-probe spectroscopy: A newand H. J. Maris, “Time-resolved pump-probe experiments withand U. Keller, “Femtosecond pump-porbe near-field optical

  7. Antibody recognition force microscopy shows that outer membrane...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Shewanella oneidensis MR-1 cells during anaerobic growth, when Fe(III) served as the terminal electron acceptor. OmcA was localized to the interface with hematite, while MtrC was...

  8. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    SciTech Connect (OSTI)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Chikoidze, E.; Dumont, Y. [GEMaC, Université de Versailles St. Quentin en Yvelines-CNRS, Versailles (France); Fanciulli, M. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy)

    2014-05-07T23:59:59.000Z

    R-Fe-O (R?=?rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er{sub 2}O{sub 3} and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO{sub 3} and ErFe{sub 2}O{sub 4} phases develop following subsequent thermal annealing processes at 850?°C in air and N{sub 2}. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  9. Influence of Atomic Layer Deposition Temperatures on TiO2/n-Si MOS Capacitor

    SciTech Connect (OSTI)

    Wei, Daming [Kansas State University; Hossain, T [Kansas State University; Garces, N. Y. [Naval Research Laboratory, Washington, D.C.; Nepal, N. [Naval Research Laboratory, Washington, D.C.; Meyer III, Harry M [ORNL; Kirkham, Melanie J [ORNL; Eddy, C.R., Jr. [Naval Research Laboratory, Washington, D.C.; Edgar, J H [Kansas State University

    2013-01-01T23:59:59.000Z

    This paper reports on the influence of temperature on the structure, composition, and electrical properties of TiO2 thin films deposited on n-type silicon (100) by atomic layer deposition (ALD). TiO2 layers around 20nm thick, deposited at temperatures ranging from 100 to 300 C, were studied. Samples deposited at 250 C and 200 C had the most uniform coverage as determined by atomic force microscopy. The average carbon concentration throughout the oxide layer and at the TiO2/Si interface was lowest at 200 C. Metal oxide semiconductor capacitors (MOSCAPs) were fabricated, and profiled by capacitance-voltage techniques. Negligible hysteresis was observed from a capacitance-voltage plot and the capacitance in the accumulation region was constant for the sample prepared at a 200 C ALD growth temperature. The interface trap density was on the order of 1013 eV-1cm-2 regardless of the deposition temperature.

  10. Structure in multilayer films of zinc sulfide and copper sulfide via atomic layer deposition

    SciTech Connect (OSTI)

    Short, Andrew; Jewell, Leila; Bielecki, Anthony; Keiber, Trevor; Bridges, Frank; Carter, Sue; Alers, Glenn, E-mail: galers@ucsc.edu [Department of Physics, University of California at Santa Cruz, 1156 High Street, Santa Cruz, California 95064 (United States)

    2014-01-15T23:59:59.000Z

    Multilayer film stacks of ZnS and Cu{sub x}S (x???2) were made via atomic layer deposition. The precursors were bis(2,2,6,6-tetramethyl-3,5-heptanedionato)zinc, bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper, and H{sub 2}S generated in situ for sulfur. Samples were deposited at 200?°C, in layers ranging from approximately 2 to 20 nm thick, based on binary growth rates. The properties of the film stacks were studied with atomic force microscopy, ultraviolet–visible spectroscopy, and extended x-ray absorption fine structure. The results demonstrate that the structure of films with the thinnest layers is dominated by Cu{sub x}S, whereas in the thicker films, the structure is determined by whichever material is first deposited. This can be attributed to the crystal structure mismatch of ZnS and Cu{sub x}S.

  11. atomic orbitals calculation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and...

  12. atomic structure calculations: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    orbital discretization. We give analytic expressions for evaluating charge density, total energy, Helmholtz free energy and atomic forces without using the eigenvalues and...

  13. DOI: 10.1002/adma.200800742 Scanning Photoemission Microscopy of

    E-Print Network [OSTI]

    Kim, Sehun

    DOI: 10.1002/adma.200800742 Scanning Photoemission Microscopy of Graphene Sheets on SiO2** By Ki in extracting individual sheets of carbon atoms (graphene) from graphite crystals, graphene has been attracted metals or molecules.[4­6] In addition, the modification of graphene surfaces using a direct chemical

  14. Design and performance of a combined secondary ion mass spectrometry-scanning probe microscopy instrument for high sensitivity and high-resolution elemental three-dimensional analysis

    SciTech Connect (OSTI)

    Wirtz, Tom; Fleming, Yves; Gerard, Mathieu [Department 'Science and Analysis of Materials' (SAM), Centre de Recherche Public, Gabriel Lippmann, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Gysin, Urs; Glatzel, Thilo; Meyer, Ernst [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Wegmann, Urs [Department of Physics, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Maier, Urs [Ferrovac GmbH, Thurgauerstr. 72, CH-8050 Zuerich (Switzerland); Odriozola, Aitziber Herrero; Uehli, Daniel [SPECS Zurich GmbH, Technoparkstr. 1, CH-8005 Zuerich (Switzerland)

    2012-06-15T23:59:59.000Z

    State-of-the-art secondary ion mass spectrometry (SIMS) instruments allow producing 3D chemical mappings with excellent sensitivity and spatial resolution. Several important artifacts however arise from the fact that SIMS 3D mapping does not take into account the surface topography of the sample. In order to correct these artifacts, we have integrated a specially developed scanning probe microscopy (SPM) system into a commercial Cameca NanoSIMS 50 instrument. This new SPM module, which was designed as a DN200CF flange-mounted bolt-on accessory, includes a new high-precision sample stage, a scanner with a range of 100 {mu}m in x and y direction, and a dedicated SPM head which can be operated in the atomic force microscopy (AFM) and Kelvin probe force microscopy modes. Topographical information gained from AFM measurements taken before, during, and after SIMS analysis as well as the SIMS data are automatically compiled into an accurate 3D reconstruction using the software program 'SARINA,' which was developed for this first combined SIMS-SPM instrument. The achievable lateral resolutions are 6 nm in the SPM mode and 45 nm in the SIMS mode. Elemental 3D images obtained with our integrated SIMS-SPM instrument on Al/Cu and polystyrene/poly(methyl methacrylate) samples demonstrate the advantages of the combined SIMS-SPM approach.

  15. Toward single cell traction microscopy within 3D collagen matrices

    SciTech Connect (OSTI)

    Hall, Matthew S. [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States); Long, Rong [Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G8 (Canada); Feng, Xinzeng [Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853 (United States); Huang, YuLing [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States); Hui, Chung-Yuen [Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853 (United States); Wu, Mingming, E-mail: mw272@cornell.edu [Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853 (United States)

    2013-10-01T23:59:59.000Z

    Mechanical interaction between the cell and its extracellular matrix (ECM) regulates cellular behaviors, including proliferation, differentiation, adhesion, and migration. Cells require the three-dimensional (3D) architectural support of the ECM to perform physiologically realistic functions. However, current understanding of cell–ECM and cell–cell mechanical interactions is largely derived from 2D cell traction force microscopy, in which cells are cultured on a flat substrate. 3D cell traction microscopy is emerging for mapping traction fields of single animal cells embedded in either synthetic or natively derived fibrous gels. We discuss here the development of 3D cell traction microscopy, its current limitations, and perspectives on the future of this technology. Emphasis is placed on strategies for applying 3D cell traction microscopy to individual tumor cell migration within collagen gels. - Highlights: • Review of the current state of the art in 3D cell traction force microscopy. • Bulk and micro-characterization of remodelable fibrous collagen gels. • Strategies for performing 3D cell traction microscopy within collagen gels.

  16. Characterization of Polymer Blends: Optical Microscopy (*Polarized, Interference and Phase Contrast Microscopy*) and Confocal Microscopy

    SciTech Connect (OSTI)

    Ramanathan, Nathan Muruganathan [ORNL; Darling, Seth B. [Argonne National Laboratory (ANL)

    2015-01-01T23:59:59.000Z

    Chapter 15 surveys the characterization of macro, micro and meso morphologies of polymer blends by optical microscopy. Confocal Microscopy offers the ability to view the three dimensional morphology of polymer blends, popular in characterization of biological systems. Confocal microscopy uses point illumination and a spatial pinhole to eliminate out-of focus light in samples that are thicker than the focal plane.

  17. Instrument Series: Microscopy 4000 XHR local electrode atom

    E-Print Network [OSTI]

    Power: > 300 mW ê Laser Wavelength: 355 nm ê Sample Temperature: 25­150K ê Laser Spot Size: Depth Resolution: 0.1 nm (using W-tip) ê Mass Resolution: Full FoV is 60° solid angle as measured from conductivity materials, such as ceramics, semiconductors and oxides True 3-D imaging ­ ~0.5 nm spatial

  18. Molecular force spectroscopy of homophilic nectin-1 interactions

    SciTech Connect (OSTI)

    Vedula, Sri Ram Krishna [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Lim, T.S. [Bioinformatics Institute (Singapore); NUS Graduate School for Integrative Sciences and Engineering (Singapore); Hui Shi [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Kausalya, P. Jaya [Institute of Molecular and Cell Biology (Singapore); Lane, E. Birgitte [Institute of Medical Biology (Singapore); Rajagopal, Gunaretnam [Bioinformatics Institute (Singapore); Hunziker, Walter [Institute of Molecular and Cell Biology (Singapore); Lim, C.T. [Division of Bioengineering and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)], E-mail: ctlim@nus.edu.sg

    2007-11-03T23:59:59.000Z

    Nectins are Ca{sup 2+} independent cell adhesion molecules localizing at the cadherin based adherens junctions. In this study, we have used atomic force microscopy to study interaction of a chimera of extra cellular fragment of nectin-1 and Fc of human IgG (nef-1) with wild type L-fibroblasts that express endogenous nectin-1 to elucidate the biophysical characteristics of homophilic nectin-1 trans-interactions at the level of single molecule. Bond strength distribution revealed three distinct bound states (or configurations) of trans-interactions between paired nectins, where each bound state has a unique unstressed off-rate and reactive compliance. Kinetic analysis of force-dependent off-rate of the bound state involving trans-interacting V-V domains between paired nectin-1 (unstressed off-rate {approx}1.465 {+-} 0.779 s{sup -1}, reactive compliance {approx}0.143 {+-} 0.072 nm) was found to be closest to E-cadherin, indicating that V-V domain trans-interactions are probably necessary to initiate and promote adhesions of E-cadherin at adherens junctions (AJs)

  19. Lift Forces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5Let us count theLienertLift Forces in Bubbly

  20. Electrostrictive and electrostatic responses in contact mode voltage modulated Scanning Probe Microscopies

    SciTech Connect (OSTI)

    Eliseev, E. A. [National Academy of Science of Ukraine, Kiev, Ukraine] [National Academy of Science of Ukraine, Kiev, Ukraine; Morozovska, A. N. [National Academy of Science of Ukraine, Kiev, Ukraine] [National Academy of Science of Ukraine, Kiev, Ukraine; Ievlev, Anton [ORNL] [ORNL; Balke, Nina [ORNL] [ORNL; Maksymovych, Petro [ORNL] [ORNL; Tselev, Alexander [ORNL] [ORNL; Kalinin, Sergei V [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Electromechanical response of solids underpins image formation mechanism of several scanning probe microscopy techniques including the piezoresponse force microscopy (PFM) and electrochemical strain microscopy (ESM). While the theory of linear piezoelectric and ionic responses are well developed, the contributions of quadratic effects including electrostriction and capacitive tip-surface forces to measured signal remain poorly understood. Here we analyze the electrostrictive and capacitive contributions to the PFM and ESM signals and discuss the implications of the dielectric tip-surface gap on these interactions.

  1. Single-layer MoS{sub 2} roughness and sliding friction quenching by interaction with atomically flat substrates

    SciTech Connect (OSTI)

    Quereda, J. [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid E-28049 (Spain); Castellanos-Gomez, A. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Agraït, N. [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid E-28049 (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA-Nanociencia, E-28049 Madrid (Spain); Instituto de Ciencia de Materiales Nicolás Cabrera, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Rubio-Bollinger, G., E-mail: gabino.rubio@uam.es [Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid E-28049 (Spain); Instituto de Ciencia de Materiales Nicolás Cabrera, Campus de Cantoblanco, E-28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid (Spain)

    2014-08-04T23:59:59.000Z

    We experimentally study the surface roughness and the lateral friction force in single-layer MoS{sub 2} crystals deposited on different substrates: SiO{sub 2}, mica, and hexagonal boron nitride (h-BN). Roughness and sliding friction measurements are performed by atomic force microscopy. We find a strong dependence of the MoS{sub 2} roughness on the underlying substrate material, being h-BN the substrate which better preserves the flatness of the MoS{sub 2} crystal. The lateral friction also lowers as the roughness decreases, and attains its lowest value for MoS{sub 2} flakes on h-BN substrates. However, it is still higher than for the surface of a bulk MoS{sub 2} crystal, which we attribute to the deformation of the flake due to competing tip-to-flake and flake-to-substrate interactions.

  2. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

    Weiss, Shimon (El Cerrito, CA); Chemla, Daniel S. (Kensington, CA); Ogletree, D. Frank (El Cerrito, CA); Botkin, David (San Francisco, CA)

    1995-01-01T23:59:59.000Z

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  3. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16T23:59:59.000Z

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  4. Radiative friction on an excited atom moving in vacuum

    E-Print Network [OSTI]

    Wei Guo

    2012-04-30T23:59:59.000Z

    It is known that, when an excited atom spontaneously emits one photon, two effects are produced. First, the atom's internal and external states are entangled with the states of the emitted photon. Second, the atom receives a momentum transfered from the photon. In this work, the dynamics of such an atom in vacuum is studied. Through a specific calculation, it is demonstrated that these effects cause the atom to experience, on average, a friction force opposite to its initial velocity. Properties of the force are also discussed.

  5. Classical Helium Atom with Radiation Reaction G. Camelio,1

    E-Print Network [OSTI]

    Carati, Andrea

    Classical Helium Atom with Radiation Reaction G. Camelio,1 A. Carati,2 and L. Galgani2 1) Universit November 2011) We study a classical model of Helium atom in which, in addition to the Coulomb forces be singular with respect to that of Lebesgue. PACS numbers: 05.45.-a, 41.60.-m Keywords: classical Helium atom

  6. Atom Interferometry

    ScienceCinema (OSTI)

    Mark Kasevich

    2010-01-08T23:59:59.000Z

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  7. The magnetic resonance force microscope: A new microscopic probe of magnetic materials

    SciTech Connect (OSTI)

    Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1997-08-06T23:59:59.000Z

    The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

  8. Classical and Quantum Chaos in Atom Optics

    E-Print Network [OSTI]

    Farhan Saif

    2006-04-10T23:59:59.000Z

    The interaction of an atom with an electromagnetic field is discussed in the presence of a time periodic external modulating force. It is explained that a control on atom by electromagnetic fields helps to design the quantum analog of classical optical systems. In these atom optical systems chaos may appear at the onset of external fields. The classical and quantum chaotic dynamics is discussed, in particular in an atom optics Fermi accelerator. It is found that the quantum dynamics exhibits dynamical localization and quantum recurrences.

  9. A national facility for biological cryo-electron microscopy

    SciTech Connect (OSTI)

    Saibil, Helen R., E-mail: h.saibil@mail.cryst.bbk.ac.uk [Birkbeck College, Malet Street, London WC1E 7HX (United Kingdom); Grünewald, Kay [University of Oxford, Oxford OX3 7BN (United Kingdom); Stuart, David I. [University of Oxford, Oxford OX3 7BN (United Kingdom); Diamond Light Source, Didcot OX11 0DE (United Kingdom); Birkbeck College, Malet Street, London WC1E 7HX (United Kingdom)

    2015-01-01T23:59:59.000Z

    This review provides a brief update on the use of cryo-electron microscopy for integrated structural biology, along with an overview of the plans for the UK national facility for electron microscopy being built at the Diamond synchrotron. Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback.

  10. ORNL microscopy directly images problematic lithium dendrites...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    865.574.7308 ORNL microscopy directly images problematic lithium dendrites in batteries ORNL electron microscopy captured the first real-time nanoscale images of the nucleation and...

  11. Measuring Atomic Properties with an Atom Interferometer

    E-Print Network [OSTI]

    Roberts, Tony David

    2006-06-28T23:59:59.000Z

    Two experiments are presented which measure atomic properties using an atom interferometer. The interferometer splits the sodium de Broglie wave into two paths,

  12. Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy

    E-Print Network [OSTI]

    Pennycook, Steve

    . Corbin1 , Niklas Dellby1 , Matthew F. Murfitt1 , Christopher S. Own1 , Zoltan S. Szilagyi1 , Mark P

  13. If Only We Could Account For Every Atom (LBNL Summer Lecture Series)

    ScienceCinema (OSTI)

    Kisielowski, Christian

    2014-05-06T23:59:59.000Z

    Christian Kisielowski, an expert in electron microscopy at Lawrence Berkeley National Laboratory, investigates ways to allow studies of single atoms using sophisticated microscopes and imaginative techniques. His goal is to account for every atom in the interior of both simple and complex materials. Find out how he and his colleagues are breaking the barriers to account for every atom.

  14. Microscopy of a scalable superatom

    E-Print Network [OSTI]

    Zeiher, Johannes; Hild, Sebastian; Macrì, Tommaso; Bloch, Immanuel; Gross, Christian

    2015-01-01T23:59:59.000Z

    Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions which lead to extreme nonlinearities in laser coupled atomic ensembles. As a result, multiple excitation of a Micrometer sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called "superatom", is a valuable resource for quantum information, providing a collective Qubit. Here we report on the preparation of two orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub shot noise precision by local manipulation of a two-dimensional Mott ins...

  15. Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint

    SciTech Connect (OSTI)

    Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

    2011-07-01T23:59:59.000Z

    Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

  16. Atomic magnetometer

    DOE Patents [OSTI]

    Schwindt, Peter (Albuquerque, NM); Johnson, Cort N. (Albuquerque, NM)

    2012-07-03T23:59:59.000Z

    An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

  17. Correlated Topographic and Spectroscopic Imaging by Combined...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by Combined Atomic Force Microscopy and Optical Microscopy. Abstract: Near-field scanning microscopy is a powerful approach to obtain topographic and spectroscopic...

  18. Instead of splitting the atom --the

    E-Print Network [OSTI]

    gravitational forces ram hydrogen atoms together to produce helium, with solar energy the byproduct. On Earth -- with helium as the waste product in addition to the energy. A huge jolt of heat (to nearly 100 million C, 180 million F) would kickstart the process, fusing the nuclei in a charged gas called a plasma. Plasma has

  19. Dynamic imaging with electron microscopy

    ScienceCinema (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-05-30T23:59:59.000Z

    Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

  20. Low-Energy Electron Microscopy Studies of Interlayer Mass Transport Kinetics on TiN(111)

    E-Print Network [OSTI]

    Israeli, Navot

    Low-Energy Electron Microscopy Studies of Interlayer Mass Transport Kinetics on TiN(111) S annealing of three-dimensional (3D) TiN(111) mounds, consisting of stacked 2D islands, at temperatures-limited decay of 2D TiN islands on atomically-flat TiN(111) terraces [Phys. Rev. Lett. 89 (2002) 176102

  1. Molecular-scale investigations of structures and surface charge distribution of surfactant aggregates by three-dimensional force mapping

    SciTech Connect (OSTI)

    Suzuki, Kazuhiro; Oyabu, Noriaki; Matsushige, Kazumi; Yamada, Hirofumi [Department of Electronic Science and Engineering, Kyoto University, Katsura, Nishikyo, Kyoto 615-8510 (Japan)] [Department of Electronic Science and Engineering, Kyoto University, Katsura, Nishikyo, Kyoto 615-8510 (Japan); Kobayashi, Kei [The Hakubi Center for Advanced Research, Kyoto University, Katsura, Nishikyo, Kyoto 615-8520 (Japan)] [The Hakubi Center for Advanced Research, Kyoto University, Katsura, Nishikyo, Kyoto 615-8520 (Japan)

    2014-02-07T23:59:59.000Z

    Surface charges on nanoscale structures in liquids, such as biomolecules and nano-micelles, play an essentially important role in their structural stability as well as their chemical activities. These structures interact with each other through electric double layers (EDLs) formed by the counter ions in electrolyte solution. Although static-mode atomic force microscopy (AFM) including colloidal-probe AFM is a powerful technique for surface charge density measurements and EDL analysis on a submicron scale in liquids, precise surface charge density analysis with single-nanometer resolution has not been made because of its limitation of the resolution and the detection sensitivity. Here we demonstrate molecular-scale surface charge measurements of self-assembled micellar structures, molecular hemicylinders of sodium dodecyl sulfate (SDS), by three-dimensional (3D) force mapping based on frequency modulation AFM. The SDS hemicylindrical structures with a diameter of 4.8 nm on a graphite surface were clearly imaged. We have succeeded in visualizing 3D EDL forces on the SDS hemicylinder surfaces and obtaining the molecular-scale charge density for the first time. The results showed that the surface charge on the trench regions between the hemicylinders was much smaller than that on the hemicylinder tops. The method can be applied to a wide variety of local charge distribution studies, such as spatial charge variation on a single protein molecule.

  2. RESEARCH ENGINEER IN ADVANCED ANALYTICAL ELECTRON MICROSCOPY

    E-Print Network [OSTI]

    Gilchrist, James F.

    RESEARCH ENGINEER IN ADVANCED ANALYTICAL ELECTRON MICROSCOPY Department of Materials Science. #12;Job Description (for website) Job Title: Research Engineer in Advanced Analytical Electron or an engineering discipline and four years of demonstrated experience in electron microscopy. Requirements

  3. Three-Nucleon Forces

    E-Print Network [OSTI]

    Peter U. Sauer

    2014-07-25T23:59:59.000Z

    The role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries towards calculationally converged results. Genuine forces make up the Hamiltonian; they represent the chosen underlying dynamics. The hierarchy of contributions arising from two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the decription of some observables. Their contributions to observables are small on the scale set by two-nucleon forces.

  4. Protective Force Program Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2000-06-30T23:59:59.000Z

    Provides detailed requirements to supplement DOE O 473.2, Protective Force Program, which establishes the requirements and responsibilities for management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Does not cancel other directives.

  5. Improved Constraints on an Axion-Mediated Force

    SciTech Connect (OSTI)

    Hoedl, S. A.; Fleischer, F.; Adelberger, E. G.; Heckel, B. R. [Center for Experimental Nuclear Physics and Astrophysics, Box 354290, University of Washington, Seattle, Washington 98195-4290 (United States)

    2011-01-28T23:59:59.000Z

    Low mass pseudoscalars, such as the axion, can mediate macroscopic parity and time-reversal symmetry-violating forces. We searched for such a force between polarized electrons and unpolarized atoms using a novel, magnetically unshielded torsion pendulum. We improved the laboratory bounds on this force by more than 10 orders of magnitude for pseudoscalars heavier than 1 meV and have constrained this force over a broad range of astrophysically interesting masses (10 {mu}eV to 10 meV).

  6. atom-atom collisions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Safronova, Marianna 3 Atom-atom correlations in colliding Bose-Einstein condensates Quantum Physics (arXiv) Summary: We analyze atom-atom correlations in the s-wave...

  7. Visual-servoing optical microscopy

    DOE Patents [OSTI]

    Callahan, Daniel E; Parvin, Bahram

    2013-10-01T23:59:59.000Z

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  8. Visual-servoing optical microscopy

    DOE Patents [OSTI]

    Callahan, Daniel E. (Martinez, CA); Parvin, Bahram (Mill Valley, CA)

    2011-05-24T23:59:59.000Z

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  9. Influence of ion-to-atom ratio on the microstructure of evaporated molybdenum thin films grown using low energy argon ions

    SciTech Connect (OSTI)

    Yadav, Praveen Kumar, E-mail: praveenyadav@rrcat.gov.in; Nayak, Maheswar; Rai, Sanjay Kumar; Lodha, Gyanendra Singh [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Sant, Tushar; Sharma, Surinder Mohan [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mukherjee, Chandrachur [Mechanical and Optical Support Section, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

    2014-03-15T23:59:59.000Z

    The authors report the effect of argon ion to molybdenum atom ratio (r) on the microstructure of low energy (70?eV) argon ion assisted electron beam evaporated Mo thin films. Surface roughness, morphology, and crystallinity of Mo films are found to strongly depend on “r.” Increase of “r” from 0 to 100 induces gradual loss in crystallinity, reduction in surface roughness and systematic increase in density of the film. For “r”???100, average atomic density of the film approaches the bulk value (97%) with lowest surface roughness. Further, increasing “r” up to 170 reduces the atomic density, increases roughness, and increase in crystallinity induced by low energy Ar ion beam. The observed surface roughness and grain size determined by x-ray reflectivity and glancing incidence x-ray diffraction correlate well with atomic force microscopy measurements. This study demonstrates that for r?=?100 one gets lowest roughness Mo film with highest density and nearly amorphous microstructure. The growth model is discussed by structural zone model.

  10. Record-Setting Microscopy Illuminates Energy Storage Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Record-Setting Microscopy Illuminates Energy Storage Materials Record-Setting Microscopy Illuminates Energy Storage Materials Print Thursday, 22 January 2015 12:10 X-ray microscopy...

  11. Scanning Tunneling Microscopy currents on locally disordered graphene

    E-Print Network [OSTI]

    Tsai, Shan-Wen; Peres, Nuno M. R.; Santos, J. E.; Ribeiro, R. M.

    2009-01-01T23:59:59.000Z

    Scanning Tunneling Microscopy currents on locally disorderedcharacteristic curves of Scanning Tunneling Microscopy (STM)for the calculation of Scanning Tunneling Microscopy (STM)

  12. Frontiers of in situ electron microscopy

    SciTech Connect (OSTI)

    Zheng, Haimei [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhu, Yimei [Brookhaven National Lab. (BNL), Upton, NY (United States); Meng, Shirley Ying [Univ. of California-San Diego, San Diego, CA (United States)

    2015-01-01T23:59:59.000Z

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by in this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.

  13. Preparation and atomic structure of reconstructed (0001) InGaN surfaces

    SciTech Connect (OSTI)

    Friedrich, C.; Biermann, A.; Kneissl, M.; Vogt, P. [Institut fuer Festkoerperphysik EW6-1, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Hoffmann, V. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Esser, N. [Institut fuer Festkoerperphysik EW6-1, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Leibniz-Institut fuer Analytische Wissenschaften - ISAS e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany)

    2012-08-01T23:59:59.000Z

    The preparation and surface structure of high quality group-III-polar (0001) InGaN layers grown by metal-organic vapor phase epitaxy have been investigated. In order to obtain a clean and well-ordered surface we studied the preparation by annealing at various temperatures under ultra high vacuum and nitrogen-rich conditions in nitrogen-plasma. We show that different InGaN surface reconstructions such as (1 Multiplication-Sign 1), (1 + 1/6), (2 Multiplication-Sign 2), and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign can be obtained as observed by low energy electron diffraction. Dependent on the annealing temperature and nitrogen supply these surfaces exhibit significant differences in stoichiometry and morphology as determined by Auger electron spectroscopy and atomic force microscopy measurements. The (1 Multiplication-Sign 1), (2 Multiplication-Sign 2), and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign superstructures are terminated by single group-III-adatoms, whereas the (1 + 1/6) exhibits a incommensurate overlayer of group-III-atoms. We show that the (2 Multiplication-Sign 2) and ({radical}(3) Multiplication-Sign {radical}(3))R30 Degree-Sign an In depletion in the first group-III layer and In or Ga adatoms in ontop position. Strain-relaxation is suggested to explain this structure formation.

  14. Nano Positioning of Single Atoms in a Micro Cavity

    E-Print Network [OSTI]

    Stefan Nussmann; Markus Hijlkema; Bernhard Weber; Felix Rohde; Gerhard Rempe; Axel Kuhn

    2005-06-10T23:59:59.000Z

    The coupling of individual atoms to a high-finesse optical cavity is precisely controlled and adjusted using a standing-wave dipole-force trap, a challenge for strong atom-cavity coupling. Ultracold Rubidium atoms are first loaded into potential minima of the dipole trap in the center of the cavity. Then we use the trap as a conveyor belt that we set into motion perpendicular to the cavity axis. This allows us to repetitively move atoms out of and back into the cavity mode with a repositioning precision of 135 nm. This makes possible to either selectively address one atom of a string of atoms by the cavity, or to simultaneously couple two precisely separated atoms to a higher mode of the cavity.

  15. atomic force microscope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shift technique. This experiment was performed at a pressure of 3x10-8 Torr with hollow glass sphere of 41.3 mcm radius. Special attention is paid to electrostatic...

  16. atomic force microscopic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shift technique. This experiment was performed at a pressure of 3x10-8 Torr with hollow glass sphere of 41.3 mcm radius. Special attention is paid to electrostatic...

  17. Momentum diffusion for coupled atom-cavity oscillators * P. Maunz,1

    E-Print Network [OSTI]

    Rempe, Gerhard

    the diffusion originating from the fluctuations of the forces due to the coupling to the vacuum modes other than to fluctuations, in par- ticular, light-force fluctuations, which heat the atom. Indeed, several experiments for the heating rate, which also gives insight into the physics of force fluc- tuations in a cavity

  18. Machine Learning for Quantum Mechanical Properties of Atoms in Molecules

    E-Print Network [OSTI]

    Rupp, Matthias; von Lilienfeld, O Anatole

    2015-01-01T23:59:59.000Z

    We introduce machine learning models of quantum mechanical observables of atoms in molecules. Instant out-of-sample predictions for proton and carbon nuclear chemical shifts, atomic core level excitations, and forces on atoms reach accuracies on par with density functional theory reference. Locality is exploited within non-linear regression via local atom-centered coordinate systems. The approach is validated on a diverse set of 9k small organic molecules. Linear scaling is demonstrated for saturated polymers with up to sub-mesoscale lengths.

  19. Probing Dark Energy with Atom Interferometry

    E-Print Network [OSTI]

    Clare Burrage; Edmund J. Copeland; E. A. Hinds

    2014-08-06T23:59:59.000Z

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  20. Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Documents & Publications Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst Characterization...

  1. Casimir force: an alternative treatment

    E-Print Network [OSTI]

    P. R. Silva

    2009-01-07T23:59:59.000Z

    The Casimir force between two parallel uncharged closely spaced metallic plates is evaluated in ways alternatives to those usually considered in the literature. In a first approximation we take in account the suppressed quantum numbers of a cubic box, representing a cavity which was cut in a metallic block. We combine these ideas with those of the MIT bag model of hadrons, but adapted to non-relativistic particles. In a second approximation we consider the particles occupying the energy levels of the Bohr atom, so that the Casimir force depends explicitly on the fine structure constant alpha. In both treatments, the mean energies which have explicit dependence on the particle mass and on the maximum occupied quantum number (related to the Fermi level of the system) at the beginning of the calculations, have these dependences mutually canceled at the end of them. Finally by comparing the averaged energies computed in both approximations, we are able to make an estimate of the value of the fine structure constant alpha.

  2. NUCLEAR PROXIMITY FORCES

    E-Print Network [OSTI]

    Randrup, J.

    2011-01-01T23:59:59.000Z

    One might summarize of nuclear potential energy has beendegree of freedom) for the nuclear interaction between anyUniversity of California. Nuclear Proximity Forces 'I< at

  3. Forces from Connes' geometry

    E-Print Network [OSTI]

    Thomas Schucker

    2007-03-26T23:59:59.000Z

    We try to give a pedagogical introduction to Connes' derivation of the standard model of electro-magnetic, weak and strong forces from gravity.

  4. Dynamic scanning probe microscopy of adsorbed molecules on graphite

    E-Print Network [OSTI]

    N. Berdunov; A. J. Pollard; P. H. Beton

    2009-01-08T23:59:59.000Z

    We have used a combined dynamic scanning tunneling and atomic force microscope to study the organisation of weakly bound adsorbed molecules on a graphite substrate. Specifically we have acquired images of islands of the perylene derivative molecules. These weakly bound molecules may be imaged in dynamic STM, in which the probe is oscillated above the surface. We show that molecular resolution may be readily attained and that a similar mode of imaging may be realised using conventional STM arrangement. We also show, using tunnelling spectroscopy, the presence of an energy gap for the adsorbed molecules confirming a weak molecule-substrate interaction.

  5. Atomizing nozzle and process

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20T23:59:59.000Z

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  6. Protective Force Program Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-12-20T23:59:59.000Z

    Provides detailed requirements to supplement DOE O 473.2, PROTECTIVE FORCE PROGRAM, which establishes the requirements and responsibilities for management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Change 1 revised pages in Chapters IV and VI on 12/20/2001.

  7. Atomic swelling upon compression

    E-Print Network [OSTI]

    V. K. Dolmatov; J. L. King

    2012-08-18T23:59:59.000Z

    The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.

  8. Particles and Forces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    amount of positive charge. How does an atom look on the inside? 1) Shooting at a bag of beans 2) Bag of equal weight but stuffed with cotton and a few small lead beads Compare the...

  9. OOTW Force Design Tools

    SciTech Connect (OSTI)

    Bell, R.E.; Hartley, D.S.III; Packard, S.L.

    1999-05-01T23:59:59.000Z

    This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

  10. Photoionization microscopy in terms of local frame transformation theory

    E-Print Network [OSTI]

    P. Giannakeas; F. Robicheaux; Chris H. Greene

    2014-10-27T23:59:59.000Z

    Two-photon ionization of an alkali-metal atom in the presence of a uniform electric field is investigated using a standardized form of local frame transformation and generalized quantum defect theory. The relevant long-range quantum defect parameters in the combined Coulombic plus Stark potential is calculated with eigenchannel R-matrix theory applied in the downstream parabolic coordinate $\\eta$. The present formulation permits us to express the corresponding microscopy observables in terms of the local frame transformation, and it gives a critical test of the accuracy of the Harmin-Fano theory permitting a scholastic investigation of the claims presented in Zhao {\\it et al.} [Phys. Rev. A 86, 053413 (2012)].

  11. Weak nuclear forces cause the strong nuclear force

    E-Print Network [OSTI]

    E. L. Koschmieder

    2007-12-11T23:59:59.000Z

    We determine the strength of the weak nuclear force which holds the lattices of the elementary particles together. We also determine the strength of the strong nuclear force which emanates from the sides of the nuclear lattices. The strong force is the sum of the unsaturated weak forces at the surface of the nuclear lattices. The strong force is then about ten to the power of 6 times stronger than the weak force between two lattice points.

  12. The application of Graphene as a sample support in Transmission Electron Microscopy

    E-Print Network [OSTI]

    Pantelic, R S; Kaiser, U; Stahlberg, H

    2012-01-01T23:59:59.000Z

    Transmission electron microscopy has witnessed rampant development and surging point resolution over the past few years. The improved imaging performance of modern electron microscopes shifts the bottleneck for image contrast and resolution to sample preparation. Hence, it is increasingly being realized that the full potential of electron microscopy will only be realized with the optimization of current sample preparation techniques. Perhaps the most recognized issues are background signal and noise contributed by sample supports, sample charging and instability. Graphene provides supports of single atom thickness, extreme physical stability, periodic structure, and ballistic electrical conductivity. As an increasing number of applications adapting graphene to their benefit emerge, we discuss the unique capabilities afforded by the use of graphene as a sample support for electron microscopy.

  13. Long Range Interactions With Laser Cooled Neutral Atoms

    SciTech Connect (OSTI)

    Gattobigio, Giovanni Luca [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne France (France); Dipartimento di Fisica dell'Universita di Ferrara, 44100 Ferrara (Italy); Michaud, Franck; Labeyrie, Guillaume; Kaiser, Robin [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne (France); Loureiro, Jorge; Mendonca, Jose Tito; Tercas, Hugo [Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Pohl, Thomas [ITAMP, 60 Garden Street, Cambridge, MA 02138 (United States)

    2008-09-07T23:59:59.000Z

    Multiple scattering of light in a trap of laser cooled neutral atoms leads to repulsion forces between the atoms. The corresponding interactions have long range behavior in 1/r{sup 2} and are thus similar to Coulomb interaction in an one component confined plasma. Consequences of these interactions will be described in this paper, including the limitation of the spatial density one can obtain in such systems and self-sustained oscillations of the cloud.

  14. Scattering approach to dispersive atom-surface interactions

    SciTech Connect (OSTI)

    Dalvit, Diego [Los Alamos National Laboratory; Messina, Riccardo [LAB KASTLER BROSSEL; Maia Neto, Paulo [INSTITUTO DE FISICA UFRJ; Lambrecht, Astrid [LAB KASTLER BROSSEL; Reynaud, Serge [LAB KASTLER BROSSEL

    2009-01-01T23:59:59.000Z

    We develop the scattering approach for the dispersive force on a ground state atom on top of a corrugated surface. We present explicit results to first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We consider in detail the correction to the proximity force approximation, and present a very simple approximation algorithm for computing the potential.

  15. Federal Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2009-07-15T23:59:59.000Z

    This Manual establishes requirements for the management and operation of the Department of Energy (DOE) Federal protective forces (FPFs). Cancels DOE M 470.4-3, Chg 1. Canceled by DOE O 473.3.

  16. Protective Force Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-02-13T23:59:59.000Z

    To prescribe Department of Energy policy, responsibilities, and requirements for the management and operation of the Protective Force Program. Chg 1 dated 2-13-95. Cancels DOE O 5632.7 and DOE O 5632.8.

  17. Strategic forces briefing

    SciTech Connect (OSTI)

    Bing, G.; Chrzanowski, P.; May, M.; Nordyke, M.

    1989-04-06T23:59:59.000Z

    The Strategic Forces Briefing'' is our attempt, accomplished over the past several months, to outline and highlight the more significant strategic force issues that must be addressed in the near future. Some issues are recurrent: the need for an effective modernized Triad and a constant concern for force survivability. Some issues derive from arms control: the Strategic Arms Reduction Talks (SALT) are sufficiently advanced to set broad numerical limits on forces, but not so constraining as to preclude choices among weapon systems and deployment modes. Finally, a new administration faced with serious budgetary problems must strive for the most effective strategic forces limited dollars can buy and support. A review of strategic forces logically begins with consideration of the missions the forces are charged with. We begin the briefing with a short review of targeting policy and implementation within the constraints of available unclassified information. We then review each element of the Triad with sections on SLBMs, ICBMs, and Air-Breathing (bomber and cruise missile) systems. A short section at the end deals with the potential impact of strategic defense on offensive force planning. We consider ABM, ASAT, and air defense; but we do not attempt to address the technical issues of strategic defense per se. The final section gives a brief overview of the tritium supply problem. We conclude with a summary of recommendations that emerge from our review. The results of calculation on the effectiveness of various weapon systems as a function of cost that are presented in the briefing are by Paul Chrzanowski.

  18. Spatially resolved quantitative mapping of thermomechanical properties and phase transition temperatures using scanning probe microscopy

    DOE Patents [OSTI]

    Jesse, Stephen; Kalinin, Sergei V; Nikiforov, Maxim P

    2013-07-09T23:59:59.000Z

    An approach for the thermomechanical characterization of phase transitions in polymeric materials (polyethyleneterephthalate) by band excitation acoustic force microscopy is developed. This methodology allows the independent measurement of resonance frequency, Q factor, and oscillation amplitude of a tip-surface contact area as a function of tip temperature, from which the thermal evolution of tip-surface spring constant and mechanical dissipation can be extracted. A heating protocol maintained a constant tip-surface contact area and constant contact force, thereby allowing for reproducible measurements and quantitative extraction of material properties including temperature dependence of indentation-based elastic and loss moduli.

  19. Improved graphite furnace atomizer

    DOE Patents [OSTI]

    Siemer, D.D.

    1983-05-18T23:59:59.000Z

    A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

  20. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

  1. Fast scanning two-photon microscopy

    E-Print Network [OSTI]

    Chang, Jeremy T

    2010-01-01T23:59:59.000Z

    Fast scanning two-photon microscopy coupled with the use light activated ion channels provides the basis for fast imaging and stimulation in the characterization of in vivo neural networks. A two-photon microscope capable ...

  2. Introduction to Scanning Microwave Microscopy Mode

    E-Print Network [OSTI]

    Anlage, Steven

    Wenhai Han Introduction to Scanning Microwave Microscopy Mode Application Note Introduction Mapping through" and meanwhile achieve sufficient sensitivity and resolution. With the invention of scanning been developed to probe materials properties. These include scanning near-field to scanning microwave

  3. Scanning Transmission Electron Microscopy Investigations of Complex...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scanning Transmission Electron Microscopy Investigations of Complex Oxides Monday, May 23, 2011 - 3:30pm SSRL Conference room 137-322 Professor Tom Vogt, NanoCenter & Department of...

  4. Researcher Supported by Atomic Energy Commission and U.S. Department...

    Broader source: Energy.gov (indexed) [DOE]

    smallest building blocks of all matter and three of nature's four forces in one single theory." Over a period of three decades starting in the 1960s, the Atomic Energy Commission,...

  5. VOLUME 82, NUMBER 26 P HY S I CA L R E V I E W L E T T E R S 28 JUNE 1999 LaserDriven Atomic Pump

    E-Print Network [OSTI]

    , and by the wind force Fw caused by the reflection of conduction electrons from these atoms. Since F d usually, as schematically depicted in Fig. 1, by exerting on it the wind force Fw , due to the absorption of electron are driven by the direct force F d due to the external field that is locally modified at the atomic site

  6. VOLUME 82, NUMBER 26 P H Y S I C A L R E V I E W L E T T E R S 28 JUNE 1999 Laser-Driven Atomic Pump

    E-Print Network [OSTI]

    by the direct force Fd due to the external field that is locally modified at the atomic site, and by the wind in Fig. 1, by exerting on it the wind force Fw, due to the absorption of electron momenta. The direct force Fw caused by the reflection of conduction electrons from these atoms. Since Fd usually dominates

  7. Atomic-resolution study of Mn tetramer clusters using scanning tunneling Rong Yang, Haiqiang Yang, and Arthur R. Smitha

    E-Print Network [OSTI]

    Atomic-resolution study of Mn tetramer clusters using scanning tunneling microscopy Rong Yang clusters is investigated. The clusters are composed of a quadrant array of Mn atoms forming a tetramer of manganese nitride, on which are stabilized peri- odic, self-organized array of MnN-bonded Mn tetramer clus

  8. In-situ Transmission Electron Microscopy and Spectroscopy Studies...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transmission Electron Microscopy and Spectroscopy Studies of Interfaces in Li-ion Batteries: Challenges and In-situ Transmission Electron Microscopy and Spectroscopy Studies of...

  9. In Situ Photoelectron Emission Microscopy of a Thermally Induced...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Emission Microscopy of a Thermally Induced Martensitic Transformation in a CuZnAI Shape Memory Alloy. In Situ Photoelectron Emission Microscopy of a Thermally Induced...

  10. Ultra-high Resolution Electron Microscopy for Catalyst Characterizatio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    high Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst Characterization 2009 DOE Hydrogen Program and Vehicle...

  11. Ultra-High Resolution Electron Microscopy for Catalyst Characterizatio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Documents & Publications Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst Characterization Catalyst...

  12. In-Situ Electron Microscopy of Electrical Energy Storage Materials...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electron Microscopy of Electrical Energy Storage Materials In-Situ Electron Microscopy of Electrical Energy Storage Materials Investigations of electrode interface and architecture...

  13. Producing and Detecting Correlated atoms

    E-Print Network [OSTI]

    Christoph I. Westbrook; Martijn Schellekens; Aurélien Perrin; Valentina Krachmalnicoff; Jose Carlos Viana Gomes; Jean-Baptiste Trebbia; Jérôme Estève; Hong Chang; Isabelle Bouchoule; Denis Boiron; Alain Aspect; Tom Jeltes; John McNamara; Wim Hogervorst; Wim Vassen

    2006-09-04T23:59:59.000Z

    We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions.We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wavemixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.

  14. Unbalanced electromagnetic forces

    E-Print Network [OSTI]

    Hansen, Craig Martin

    1974-01-01T23:59:59.000Z

    coils V ? 4 Vertical spring suspension experiment V ? 5 Horizontal suspension experiment 74 V ? 6 Linear plot of data for egg-shaped coil; horizontal suspension experiment V ? 7 Log-log plot of data for egg-shaped coil; horizontal suspension... segment L on straight line current segment L 53 V-1 Geometrical configuration of experimental coils. . . 62 V ? 2 Retational system for measuring force in various size points 65 xi ~Fi ure V ? 3 Rotational system for measuring force in egg-shaped...

  15. Classical Helium Atom with Radiation Reaction

    E-Print Network [OSTI]

    G. Camelio; A. Carati; L. Galgani

    2011-11-24T23:59:59.000Z

    We study a classical model of Helium atom in which, in addition to the Coulomb forces, the radiation reaction forces are taken into account. This modification brings in the model a new qualitative feature of a global character. Indeed, as pointed out by Dirac, in any model of classical electrodynamics of point particles involving radiation reaction one has to eliminate, from the a priori conceivable solutions of the problem, those corresponding to the emission of an infinite amount of energy. We show that the Dirac prescription solves a problem of inconsistency plaguing all available models which neglect radiation reaction, namely, the fact that in all such models most initial data lead to a spontaneous breakdown of the atom. A further modification is that the system thus acquires a peculiar form of dissipation. In particular, this makes attractive an invariant manifold of special physical interest, the zero--dipole manifold, that corresponds to motions in which no energy is radiated away (in the dipole approximation). We finally study numerically the invariant measure naturally induced by the time--evolution on such a manifold, and this corresponds to studying the formation process of the atom. Indications are given that such a measure may be singular with respect to that of Lebesgue.

  16. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  17. Protective Force Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2000-06-30T23:59:59.000Z

    Establishes policy, requirements, responsibilities, and authorities, for the management and operation of the Department of Energy (DOE) Protective Force (PF) Program. Extended until 7-7-06 by DOE N 251.64, dated 7-7-05 Cancels: DOE 5632.7A

  18. Contractor Protective Force

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-11-05T23:59:59.000Z

    This Manual establishes requirements for the management and operation of the U.S. Department of Energy contractor protective forces. Cancels: DOE M 470.4-3 Chg 1, CRD (Attachment 2) only, except for Section C. Canceled by DOE O 473.3.

  19. Work Force Discipline

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1983-03-23T23:59:59.000Z

    The order provides guidance and procedures and states responsibilities for maintaining work force discipline in DOE. Chg 1, dated 3-11-85; Chg 2, dated 1-6-86; Chg 3, dated 3-21-89; Chg 4, dated 8-2-90; Chg 5, dated 3-9-92; Chg 6, dated 8-21-92, cancels Chg 5.

  20. Portable dual field gradient force multichannel flow cytometer device with a dual wavelength low noise detection scheme

    DOE Patents [OSTI]

    James, Conrad D; Galambos, Paul C; Derzon, Mark S; Graf, Darin C; Pohl, Kenneth R; Bourdon, Chris J

    2012-10-23T23:59:59.000Z

    Systems and methods for combining dielectrophoresis, magnetic forces, and hydrodynamic forces to manipulate particles in channels formed on top of an electrode substrate are discussed. A magnet placed in contact under the electrode substrate while particles are flowing within the channel above the electrode substrate allows these three forces to be balanced when the system is in operation. An optical detection scheme using near-confocal microscopy for simultaneously detecting two wavelengths of light emitted from the flowing particles is also discussed.

  1. Bending buckling of single-walled carbon nanotubes by atomic-scale finite element

    E-Print Network [OSTI]

    Jiang, Hanqing

    - vered SWNT loaded by a follower lateral force at the free end and found that it exhibited local bucklingBending buckling of single-walled carbon nanotubes by atomic-scale finite element X. Guo a , A Abstract This paper employs the atomic-scale finite element method to study bending buckling of single

  2. Atom chip apparatus for experiments with ultracold rubidium and potassium gases

    SciTech Connect (OSTI)

    Ivory, M. K.; Ziltz, A. R.; Fancher, C. T.; Pyle, A. J.; Sensharma, A.; Chase, B.; Field, J. P.; Garcia, A.; Aubin, S., E-mail: saaubi@wm.edu [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187 (United States); Jervis, D. [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)] [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

    2014-04-15T23:59:59.000Z

    We present a dual chamber atom chip apparatus for generating ultracold {sup 87}Rb and {sup 39}K atomic gases. The apparatus produces quasi-pure Bose-Einstein condensates of 10{sup 4} {sup 87}Rb atoms in an atom chip trap that features a dimple and good optical access. We have also demonstrated production of ultracold {sup 39}K and subsequent loading into the chip trap. We describe the details of the dual chamber vacuum system, the cooling lasers, the magnetic trap, the multicoil magnetic transport system, the atom chip, and two optical dipole traps. Due in part to the use of light-induced atom desorption, the laser cooling chamber features a sufficiently good vacuum to also support optical dipole trap-based experiments. The apparatus is well suited for studies of atom-surface forces, quantum pumping and transport experiments, atom interferometry, novel chip-based traps, and studies of one-dimensional many-body systems.

  3. Materials Properties at Internal Interfaces: Fundamental Atomic Issues

    SciTech Connect (OSTI)

    Browning, Nigel

    2014-09-12T23:59:59.000Z

    During the course of this research, the microscopy methods were applied to many different systems (see publication list). However, the work can be broadly classified into three main areas: the statistical distribution of grain boundary structures under different doping conditions, the identification of individual dopant atoms in oxide materials, and the evaluation of nucleation and growth processes in liquid and more recently. The main results from each of these efforts will be discussed in the final report.

  4. Infrared Scattering Scanning Near-Field Optical Microscopy Using An External Cavity Quantum Cascade Laser For Nanoscale Chemical Imaging And Spectroscopy of Explosive Residues

    SciTech Connect (OSTI)

    Craig, Ian M.; Phillips, Mark C.; Taubman, Matthew S.; Josberger, Erik E.; Raschke, Markus Bernd

    2013-02-04T23:59:59.000Z

    Infrared scattering scanning near-field optical microscopy (s-SNOM) is an apertureless superfocusing technique that uses the antenna properties of a conducting atomic force microscope (AFM) tip to achieve infrared spatial resolution below the diffraction limit. The instrument can be used either in imaging mode, where a fixed wavelength light source is tuned to a molecular resonance and the AFM raster scans an image, or in spectroscopy mode where the AFM is held stationary over a feature of interest and the light frequency is varied to obtain a spectrum. In either case, a strong, stable, coherent infrared source is required. Here we demonstrate the integration of a broadly tunable external cavity quantum cascade laser (ECQCL) into an s-SNOM and use it to obtain infrared spectra of microcrystals of chemicals adsorbed onto gold substrates. Residues of the explosive compound tetryl was deposited onto gold substrates. s-SNOM experiments were performed in the 1260-1400 cm?1 tuning range of the ECQCL, corresponding to the NO2 symmetric stretch vibrational fingerprint region. Vibrational infrared spectra were collected on individual chemical domains with a collection area of *500nm2 and compared to ensemble averaged far-field reflection-absorption infrared spectroscopy (RAIRS) results.

  5. A 4 K cryogenic probe for use in magnetic resonance force microscopy experiments

    SciTech Connect (OSTI)

    Smith, Doran D.; Alexson, Dimitri A. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)] [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States); Garbini, Joseph L. [Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States)] [Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States)

    2013-09-15T23:59:59.000Z

    The detailed design of a mechanically detected nuclear magnetic resonance probe using the SPAM (Springiness Preservation by Aligning Magnetization) geometry, operating at 4 K, in vacuum, and a several-Tesla magnetic field is described. The probe head is vibration-isolated well enough from the environment by a three-spring suspension system that the cantilever achieves thermal equilibrium with the environment without the aid of eddy current damping. The probe uses an ultra-soft Si cantilever with a Ni sphere attached to its tip, and magnetic resonance is registered as a change in the resonant frequency of the driven cantilever. The RF system uses frequency sweeps for adiabatic rapid passage using a 500 ?m diameter RF coil wound around a sapphire rod. The RF coil and optical fiber of the interferometer used to sense the cantilever's position are both located with respect to the cantilever using a Garbini micropositioner, and the sample stage is mounted on an Attocube nanopositioner.

  6. Surface characterization of cross-linked elastomers by shear modulation force microscopy

    E-Print Network [OSTI]

    Colby, Ralph H.

    (isobutylene-co-4-methylstyrene) (BIMS) is a synthetic terpolymer which can be stoichiometrically cross-linked by N agreement with rubber elasticity theory was obtained in both cases. The SMFM was then used to monitor), a synthetic terpolymer of isobutylene (IB), paramethylstyrene (PMS), and parabromomethylstyrene (Br

  7. Measuring Forces between Protein Fibers by Microscopy Christopher W. Jones,* J. C. Wang,y

    E-Print Network [OSTI]

    Turner, Matthew

    b-amyloid, actin, and tubulin. INTRODUCTION Sickle cell anemia is a blood disorder in which and the associated pathologies can be found in Eaton and Hofrichter (1990). The main pathology of sickle cell anemia a genetic mutation leads to the transcription of sickle hemoglobin (HbS). A good review of sickle cell

  8. Atomic and molecular supernovae

    SciTech Connect (OSTI)

    Liu, W.

    1997-12-01T23:59:59.000Z

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  9. Impact of graphene coating on the atom-plate interaction

    E-Print Network [OSTI]

    G. L. Klimchitskaya; V. M. Mostepanenko

    2014-06-23T23:59:59.000Z

    Using the recently proposed quantum electrodynamical formalism, we calculate the Casimir-Polder free energies and forces between the ground state atoms of Rb, Na, Cs and He${}^{\\ast}$ and the plates made of Au, Si, sapphire and fused silica coated with a graphene sheet. It is shown that the graphene coating has no effect on the Casimir-Polder interaction for metallic plates, but influences significantly for plates made of dielectric materials. The influence of graphene coating increases with decreasing static dielectric permittivity of the plate material and the characteristic frequency of an atomic dynamic polarizability. Simple analytic expressions for the classical limit of the Casimir-Polder free energy and force between an atom and a graphene-coated plate are obtained. From the comparison with the results of numerical computations, the application region of these expressions is determined.

  10. Image Scanning Microscopy Claus B. Muller and Jorg Enderlein*

    E-Print Network [OSTI]

    Enderlein, Jörg

    Image Scanning Microscopy Claus B. Mu¨ller and Jo¨rg Enderlein* III. Institute of Physics, Georg microscopy technique is introduced, image scanning microscopy (ISM), which combines conventional confocal-laser scanning microscopy with fast wide-field CCD detection. The technique allows for doubling the lateral

  11. Potential applications of microscopy for steam coal

    SciTech Connect (OSTI)

    DeVanney, K.F.; Clarkson, R.J.

    1995-08-01T23:59:59.000Z

    Optical microscopy has been an extremely useful tool for many industrial sectors in the past. This paper introduces some of the potential applications of using coal and fly ash carbon microscopy for the combustion process and steam coal industry. Coal and fly ash carbon microscopic classification criteria are described. Plant sample data are presented which demonstrate that these techniques can be useful for coal selection and for problem solving in the coal-fired power plant environment. Practical recommendations for further study are proposed.

  12. Atomizing nozzle and method

    DOE Patents [OSTI]

    Ting, Jason (Ames, IA); Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2000-03-16T23:59:59.000Z

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  13. Optical atomic magnetometer

    DOE Patents [OSTI]

    Budker, Dmitry; Higbie, James; Corsini, Eric P

    2013-11-19T23:59:59.000Z

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  14. Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory

    SciTech Connect (OSTI)

    Zhu,Y.; Wall, J.

    2008-04-01T23:59:59.000Z

    The last decade witnessed the rapid development and implementation of aberration correction in electron optics, realizing a more-than-70-year-old dream of aberration-free electron microscopy with a spatial resolution below one angstrom [1-9]. With sophisticated aberration correctors, modern electron microscopes now can reveal local structural information unavailable with neutrons and x-rays, such as the local arrangement of atoms, order/disorder, electronic inhomogeneity, bonding states, spin configuration, quantum confinement, and symmetry breaking [10-17]. Aberration correction through multipole-based correctors, as well as the associated improved stability in accelerating voltage, lens supplies, and goniometers in electron microscopes now enables medium-voltage (200-300kV) microscopes to achieve image resolution at or below 0.1nm. Aberration correction not only improves the instrument's spatial resolution but, equally importantly, allows larger objective lens pole-piece gaps to be employed thus realizing the potential of the instrument as a nanoscale property-measurement tool. That is, while retaining high spatial resolution, we can use various sample stages to observe the materials response under various temperature, electric- and magnetic- fields, and atmospheric environments. Such capabilities afford tremendous opportunities to tackle challenging science and technology issues in physics, chemistry, materials science, and biology. The research goal of the electron microscopy group at the Dept. of Condensed Matter Physics and Materials Science and the Center for Functional Nanomaterials, as well as the Institute for Advanced Electron Microscopy, Brookhaven National Laboratory (BNL), is to elucidate the microscopic origin of the physical- and chemical-behavior of materials, and the role of individual, or groups of atoms, especially in their native functional environments. We plan to accomplish this by developing and implementing various quantitative electron microscopy techniques in strongly correlated electron systems and nanostructured materials. As a first step, with the support of Materials Science Division, Office of Basic Energy Science, US Department of Energy, and the New York State Office of Science, Technology, and Academic Research, recently we acquired three aberration-corrected electron microscopes from the three major microscope manufacturers, i.e., JEOL, Hitachi, and FEI. The Hitachi HD2700C is equipped with a probe corrector, the FEI Titan 80-300 has an imaging corrector, while the JEOL2200MCO has both. All the correctors are of the dual-hexapole type, designed and manufactured by CEOS GmbH based on the design due to Rose and Haider [3, 18]. All these three are one-of-a-kind in the US, designed for specialized capabilities in characterizing nanoscale structure. In this chapter, we review the performance of these state-of-the art instruments and the new challenges associated with the improved spatial resolution, including the environment requirements of the laboratory that hosts these instruments. Although each instrument we describe here has its own strengths and drawbacks, it is not our intention to rank them in terms of their performance, especially their spatial resolution in imaging.

  15. Force Modulator System

    SciTech Connect (OSTI)

    Redmond Clark

    2009-04-30T23:59:59.000Z

    Many metal parts manufacturers use large metal presses to shape sheet metal into finished products like car body parts, jet wing and fuselage surfaces, etc. These metal presses take sheet metal and - with enormous force - reshape the metal into a fully formed part in a manner of seconds. Although highly efficient, the forces involved in forming metal parts also damage the press itself, limit the metals used in part production, slow press operations and, when not properly controlled, cause the manufacture of large volumes of defective metal parts. To date, the metal-forming industry has not been able to develop a metal-holding technology that allows full control of press forces during the part forming process. This is of particular importance in the automotive lightweighting efforts under way in the US automotive manufacturing marketplace. Metalforming Controls Technology Inc. (MC2) has developed a patented press control system called the Force Modulator that has the ability to control these press forces, allowing a breakthrough in stamping process control. The technology includes a series of hydraulic cylinders that provide controlled tonnage at all points in the forming process. At the same time, the unique cylinder design allows for the generation of very high levels of clamping forces (very high tonnages) in very small spaces; a requirement for forming medium and large panels out of HSS and AHSS. Successful production application of these systems testing at multiple stamping operations - including Ford and Chrysler - has validated the capabilities and economic benefits of the system. Although this technology has been adopted in a number of stamping operations, one of the primary barriers to faster adoption and application of this technology in HSS projects is system cost. The cost issue has surfaced because the systems currently in use are built for each individual die as a custom application, thus driving higher tooling costs. This project proposed to better marry the die-specific Force Modulator technology with stamping presses in the form of a press cushion. This system would be designed to operate the binder ring for multiple parts, thus cutting the per-die cost of the technology. This study reports the results of technology field application. This project produced the following conclusions: (1) The Force Modulator system is capable of operating at very high tempos in the stamping environment; (2) The company can generate substantial, controlled holding tonnage (binder ring pressure) necessary to hold high strength steel parts for proper formation during draw operations; (3) A single system can be designed to operate with a family of parts, thus significantly reducing the per-die cost of a FM system; (4) High strength steel parts made with these systems appear to show significant quality improvements; (5) The amounts of steel required to make these parts is typically less than the amounts required with traditional blank-holding technologies; and (6) This technology will aid in the use of higher strength steels in auto and truck production, thus reducing weight and improving fuel efficiency.

  16. Atom-interferometry constraints on dark energy

    E-Print Network [OSTI]

    Hamilton, Paul; Haslinger, Philipp; Simmons, Quinn; Müller, Holger; Khoury, Justin

    2015-01-01T23:59:59.000Z

    If dark energy---which drives the accelerated expansion of the universe---consists of a new light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity. There has, however, been much theoretical progress in developing theories with screening mechanisms, which can evade detection by suppressing forces in regions of high density, such as the laboratory. One prominent example is the chameleon field. We reduce the effect of this screening mechanism by probing the chameleon with individual atoms rather than bulk matter. Using a cesium matter-wave interferometer near a spherical mass in an ultra-high vacuum chamber, we constrain a wide class of dynamical dark energy theories. Our experiment excludes a range of chameleon theories that reproduce the observed cosmic acceleration.

  17. Atomic mass compilation 2012

    SciTech Connect (OSTI)

    Pfeiffer, B., E-mail: bpfeiffe@uni-mainz.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Venkataramaniah, K. [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India)] [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India); Czok, U. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)] [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); Scheidenberger, C. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)

    2014-03-15T23:59:59.000Z

    Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

  18. Instrument Series: Microscopy Aberration-Corrected

    E-Print Network [OSTI]

    , and material defects Chemistry ­ understanding particle surface interactions, atomic-level structure-tilt Crystallographic and Tomographic Analysis Ì Silicon-Lithium [Si(Li)] X-ray EDS Ì Cryogenic Imaging Capability Ì

  19. Cr Atom Alignment in Cr-Delta-Doped GaN

    SciTech Connect (OSTI)

    Kimura, S.; Emura, S.; Zhou, Y. K.; Choi, S. W.; Yamauchi, Y.; Hasegawa, S.; Asahi, H. [Institute of Scientific and Industrial Research, Osaka University, 8-1, Mihogaoka, Osaka, 567-0047 (Japan); Ofuchi, H. [SPring-8 / Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198 (Japan); Nakata, Y. [College of Science and Engineering, Iwaki Meisei University, Iwaki, Fukushima 970-8551 (Japan)

    2007-02-02T23:59:59.000Z

    Structural properties and Cr atom alignments in Cr-delta doped GaN grown by molecular beam epitaxy are studied with transmission electron microscopy and X-ray absorption fine structure (XAFS) measurements. It is found that the environment around Cr atoms in delta-doped samples is dramatically changed under various growth conditions. The XAFS analysis of these synthesized layers suggests that new Cr-related complexes are grown.

  20. Design and Characterization of a Field-Switchable Nanomagnetic Atom Mirror

    E-Print Network [OSTI]

    Hayward, T J; Weatherill, K J; Curran, P J; Fry, P W; Fundi, P M; Gibbs, M R J; Schrefl, T; Adams, C S; Hughes, I G; Bending, S J; Allwood, D A

    2010-01-01T23:59:59.000Z

    We present a design for a switchable nanomagnetic atom mirror formed by an array of 180{\\deg} domain walls confined within Ni80Fe20 planar nanowires. A simple analytical model is developed which allows the magnetic field produced by the domain wall array to be calculated. This model is then used to optimize the geometry of the nanowires so as to maximize the reflectivity of the atom mirror. We then describe the fabrication of a nanowire array and characterize its magnetic behavior using magneto-optic Kerr effect magnetometry, scanning Hall probe microscopy and micromagnetic simulations, demonstrating how the mobility of the domain walls allow the atom mirror to be switched "on" and "off" in a manner which would be impossible for conventional designs. Finally, we model the reflection of 87Rb atoms from the atom mirror's surface, showing that our design is well suited for investigating interactions between domain walls and cold atoms.

  1. Spatial resolution in vector potential photoelectron microscopy

    SciTech Connect (OSTI)

    Browning, R. [R. Browning Consultants, 1 Barnhart Place, Shoreham, New York 11786 (United States)] [R. Browning Consultants, 1 Barnhart Place, Shoreham, New York 11786 (United States)

    2014-03-15T23:59:59.000Z

    The experimental spatial resolution of vector potential photoelectron microscopy is found to be much higher than expected because of the cancellation of one of the expected contributions to the point spread function. We present a new calculation of the spatial resolution with support from finite element ray tracing, and experimental results.

  2. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    A. Deltuva

    2012-03-28T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  3. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    Deltuva, A

    2012-01-01T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  4. Tools for macromolecular model building and refinement into electron cryo-microscopy reconstructions

    SciTech Connect (OSTI)

    Brown, Alan; Long, Fei; Nicholls, Robert A.; Toots, Jaan; Emsley, Paul; Murshudov, Garib, E-mail: garib@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (United Kingdom)

    2015-01-01T23:59:59.000Z

    A description is given of new tools to facilitate model building and refinement into electron cryo-microscopy reconstructions. The recent rapid development of single-particle electron cryo-microscopy (cryo-EM) now allows structures to be solved by this method at resolutions close to 3 Å. Here, a number of tools to facilitate the interpretation of EM reconstructions with stereochemically reasonable all-atom models are described. The BALBES database has been repurposed as a tool for identifying protein folds from density maps. Modifications to Coot, including new Jiggle Fit and morphing tools and improved handling of nucleic acids, enhance its functionality for interpreting EM maps. REFMAC has been modified for optimal fitting of atomic models into EM maps. As external structural information can enhance the reliability of the derived atomic models, stabilize refinement and reduce overfitting, ProSMART has been extended to generate interatomic distance restraints from nucleic acid reference structures, and a new tool, LIBG, has been developed to generate nucleic acid base-pair and parallel-plane restraints. Furthermore, restraint generation has been integrated with visualization and editing in Coot, and these restraints have been applied to both real-space refinement in Coot and reciprocal-space refinement in REFMAC.

  5. Relativistic forces in Lagangian mechanics

    E-Print Network [OSTI]

    J. Muñoz Díaz

    2012-06-07T23:59:59.000Z

    We give a general definition of \\emph{relativistic force} in the context of Lagrangian mechanics. Once this is done we prove that the only relativistic forces which are linear on the velocities are those coming from differential 2-forms defined on the configuration space. In this sense, electromagnetic fields provide a mechanical system with the simplest type of relativistic forces.

  6. The Use Of Scanning Probe Microscopy To Investigate Crystal-Fluid Interfaces

    SciTech Connect (OSTI)

    Orme, C A; Giocondi, J L

    2007-04-16T23:59:59.000Z

    Over the past decade there has been a natural drive to extend the investigation of dynamic surfaces in fluid environments to higher resolution characterization tools. Various aspects of solution crystal growth have been directly visualized for the first time. These include island nucleation and growth using transmission electron microscopy and scanning tunneling microscopy; elemental step motion using scanning probe microscopy; and the time evolution of interfacial atomic structure using various diffraction techniques. In this lecture we will discuss the use of one such in situ method, scanning probe microscopy, as a means of measuring surface dynamics during crystal growth and dissolution. We will cover both practical aspects of imaging such as environmental control, fluid flow, and electrochemical manipulation, as well as the types of physical measurements that can be made. Measurements such as step motion, critical lengths, nucleation density, and step fluctuations, will be put in context of the information they provide about mechanistic processes at surfaces using examples from metal and mineral crystal growth.

  7. Understanding external forces acting on cells control lipid membrane structure and dynamics

    E-Print Network [OSTI]

    Bjørnstad, Ottar Nordal

    Understanding external forces acting on cells control lipid membrane structure and dynamics Overview: Plasma membranes composed of a variety of lipids and proteins are complex and dynamic structures optical microscopy. Much of the molecular insights into the structure and dynamics of these structures has

  8. Atomic control and characterization of surface defect states of TiO{sub 2} terminated SrTiO{sub 3} single crystals

    SciTech Connect (OSTI)

    Kareev, M.; Prosandeev, S.; Liu, J.; Gan, C.; Kareev, A.; Xiao, Min; Chakhalian, J. [University of Arkansas, Fayetteville, Arkansas 72701 (United States); Freeland, J. W. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2008-08-11T23:59:59.000Z

    By using an alternative wet-etch procedure, we have obtained high-quality atomically flat TiO{sub 2} terminated surfaces of SrTiO{sub 3} single crystals with the morphology equivalent to that of the conventional wet-etch methods. By applying a combined power of photoluminescence (PL) spectroscopy, reflection high-energy electron diffraction, atomic force microscopy imaging, and soft x-ray absorption (XAS), we were able to identify and monitor the complex evolution of oxygen defect states and Ti valency at the surface and near-surface layers. Our experiments revealed a high level of local defects resulting in the presence of the Ti{sup 3+} states at the surface. We have developed a method to control the defect states capable of a marked reduction of the defect concentration. We have demonstrated that the PL and XAS are able to distinguish the surface-related Ti{sup 3+} states from oxygen vacancies trapping charge transfer vibronic excitons that define the PL intensity. The experimental findings will have important implications for the growth of high-quality ultrathin complex oxide heterostructures.

  9. Atomic control and characterization of surface defect states of TiO(sub 2) terminated SrTiO(sub 3) single crystals.

    SciTech Connect (OSTI)

    Kareev, M.; Prosandeev, S.; Liu, J.; Gan, C.; Kareev, A.; Freeland, J. W.; Xiao, M.; Chakhalian, J.; Univ. of Arkansas

    2008-08-11T23:59:59.000Z

    By using an alternative wet-etch procedure, we have obtained high-quality atomically flat TiO{sub 2} terminated surfaces of SrTiO{sub 3} single crystals with the morphology equivalent to that of the conventional wet-etch methods. By applying a combined power of photoluminescence (PL) spectroscopy, reflection high-energy electron diffraction, atomic force microscopy imaging, and soft x-ray absorption (XAS), we were able to identify and monitor the complex evolution of oxygen defect states and Ti valency at the surface and near-surface layers. Our experiments revealed a high level of local defects resulting in the presence of the Ti{sup 3+} states at the surface. We have developed a method to control the defect states capable of a marked reduction of the defect concentration. We have demonstrated that the PL and XAS are able to distinguish the surface-related Ti{sup 3+} states from oxygen vacancies trapping charge transfer vibronic excitons that define the PL intensity. The experimental findings will have important implications for the growth of high-quality ultrathin complex oxide heterostructures.

  10. Atomic-scale and three-dimensional transmission electron microscopy of nanoparticle morphology

    E-Print Network [OSTI]

    Leary, Rowan Kendall

    2015-02-03T23:59:59.000Z

    nanoparticles with reactive concave surfaces. A compressed sensing-electron tomography (CS-ET) approach. Nano Letters, 11(11): 4666-4673, 2011. Peer reviewed conference proceedings R. Leary, Z. Saghi, P.A. Midgley, and D.J. Holland. Compressed Sensing Electron... algorithms, precision in component fabrication and stability of electrical components that AC optics yielded performance improvements in practice. First generation AC optics have addressed the major limiting aberration, third-order spherical aberration. In a...

  11. Atom microscopy via two-photon spontaneous emission spectroscopy RID A-5077-2009

    E-Print Network [OSTI]

    Qamar, Sajid; Evers, Joerg; Zubairy, M. Suhail

    2009-01-01T23:59:59.000Z

    #1;e?i#1;#7;k?#6;2#2;t#3;e?i#6;1tC1#1;t#2; ? ei#6;1tC2#1;t#2;#4; + 1 2#8;q gqe i#1;#7;q+#6;2#2;tCe k,q#1;t#2; , #1;6c#2; C? 4 k#1;t#2; = 1 2 gk #1;e?i#1;#7;k+#6;2#2;t#3;e?i#6;1tC1#1;t#2; ? ei#6;1tC2#1;t#2;#4; ? 1 2#8;q gqe i#1;#7;q?#6...;2#2;tCe k,q#1;t#2; , #1;6d#2; C? e k,q#1;t#2; = 1 2gq #1;e?i#7;qt#3;e?i#6;2tC3k#1;t#2; ? C4k#1;t#2;ei#6;2t#4; . #1;6e#2; In the long-time limit, #5;#12;#1;t ? #14;#2;#6; = #8; k,q Ce k,q#1;#14;#2;#5;e,1k,1q#6; . #1;7#2; The final...

  12. Transmission Electron Microscopy and Theoretical Analysis of AuCu Nanoparticles: Atomic Distribution

    E-Print Network [OSTI]

    Wang, Zhong L.

    de Investigacio´n y Desarrollo de Ductos, Instituto Mexicano del Petroleo, Eje Central La´zaro Ca´rdenas No. 152, Col. San Bartolo Atepehuacan, C.P.07730, Mexico D.F., Mexico 2 Instituto de Fi´sica, Universidad Auto´noma de Puebla, Apdo. Postal J-48, Puebla, Pue. 72570, Mexico 3 Instituto de Investigaciones

  13. Casimir force driven ratchets

    E-Print Network [OSTI]

    Thorsten Emig

    2007-01-26T23:59:59.000Z

    We explore the non-linear dynamics of two parallel periodically patterned metal surfaces that are coupled by the zero-point fluctuations of the electromagnetic field between them. The resulting Casimir force generates for asymmetric patterns with a time-periodically driven surface-to-surface distance a ratchet effect, allowing for directed lateral motion of the surfaces in sizeable parameter ranges. It is crucial to take into account inertia effects and hence chaotic dynamics which are described by Langevin dynamics. Multiple velocity reversals occur as a function of driving, mean surface distance, and effective damping. These transport properties are shown to be stable against weak ambient noise.

  14. Work Force Restructuring Activities

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy China 2015ofDepartment of EnergyThePatricia Hoffman is theDr.Ulrike1, 2014Force

  15. Photoemission electron microscopy of localized surface plasmons in silver nanostructures at telecommunication wavelengths

    E-Print Network [OSTI]

    Mårsell, Erik; Arnold, Cord L; Xu, Hongxing; Mauritsson, Johan; Mikkelsen, Anders

    2015-01-01T23:59:59.000Z

    We image the field enhancement at Ag nanostructures using femtosecond laser pulses with a center wavelength of 1.55 micrometer. Imaging is based on non-linear photoemission observed in a photoemission electron microscope (PEEM). The images are directly compared to ultra violet PEEM and scanning electron microscopy (SEM) imaging of the same structures. Further, we have carried out atomic scale scanning tunneling microscopy (STM) on the same type of Ag nanostructures and on the Au substrate. Measuring the photoelectron spectrum from individual Ag particles shows a larger contribution from higher order photoemission process above the work function threshold than would be predicted by a fully perturbative model, consistent with recent results using shorter wavelengths. Investigating a wide selection of both Ag nanoparticles and nanowires, field enhancement is observed from 30% of the Ag nanoparticles and from none of the nanowires. No laser-induced damage is observed of the nanostructures neither during the PEEM ...

  16. Pairing forces in nuclei

    SciTech Connect (OSTI)

    Chasman, R.R. [Argonne National Lab., IL (United States). Physics Div.

    1996-12-31T23:59:59.000Z

    In this contribution, the author mentions some features of pairing forces that are unique to nuclei and cover some areas of major interest in nuclear structure research, that involve pairing. At the level of most nuclear structure studies, nuclei are treated as consisting of two kinds of fermions (protons and neutrons) in a valence space with rather few levels. These features give rise to unique aspects of pairing forces in nuclei: (1) n-p pairing in T = 0 as well as the usual T = 1 pairing that is characteristic of like fermions; (2) a need to correct pairing calculations for the (1/N) effects that can typically be neglected in superconducting solids. An issue of current concern is the nature of the pairing interaction: several recent studies suggest a need for a density dependent form of the pairing interaction. There is a good deal of feedback between the questions of accurate calculations of pairing interactions and the form and magnitude of the pairing interaction. Finally, the authors discuss some many-body wave functions that are a generalization of the BCS wave function form, and apply them to a calculation of energy level spacings in superdeformed rotational bands.

  17. Iowa Powder Atomization Technologies

    ScienceCinema (OSTI)

    None

    2013-03-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  18. Iowa Powder Atomization Technologies

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  19. Single particle microscopy with nanometer resolution

    E-Print Network [OSTI]

    Georg Jacob; Karin Groot-Berning; Sebastian Wolf; Stefan Ulm; Luc Couturier; Ulrich G. Poschinger; Ferdinand Schmidt-Kaler; Kilian Singer

    2014-05-26T23:59:59.000Z

    We experimentally demonstrate nanoscopic transmission microscopy relying on a deterministic single particle source. This increases the signal-to-noise ratio with respect to conventional microscopy methods, which employ Poissonian particle sources. We use laser-cooled ions extracted from a Paul trap, and demonstrate remote imaging of transmissive objects with a resolution of 8.6 $\\pm$ 2.0nm and a minimum two-sample deviation of the beam position of 1.5nm. Detector dark counts can be suppressed by 6 orders of magnitudes through gating by the extraction event. The deterministic nature of our source enables an information-gain driven approach to imaging. We demonstrate this by performing efficient beam characterization based on a Bayes experiment design method.

  20. Three-wire magnetic trap for direct forced evaporative cooling Shengwang Du1,* and Eun Oh2

    E-Print Network [OSTI]

    Du, Shengwang

    Three-wire magnetic trap for direct forced evaporative cooling Shengwang Du1,* and Eun Oh2 1 Kong, China 2 U.S. Naval Research Laboratory, Remote Sensing Division, Washington, D.C. 20375, USA potential for direct forced evaporative cooling of neutral atoms without using induced spin

  1. Reliable strain measurement in transistor arrays by robust scanning transmission electron microscopy

    SciTech Connect (OSTI)

    Kim, Suhyun; Kim, Joong Jung; Jung, Younheum; Lee, Kyungwoo; Byun, Gwangsun; Hwang, KyoungHwan; Lee, Sunyoung; Lee, Kyupil [Memory Analysis Science and Engineering Group, Samsung Electronics, San 16, Hwasung City, Gyeonggi-Do 445-701 (Korea, Republic of)] [Memory Analysis Science and Engineering Group, Samsung Electronics, San 16, Hwasung City, Gyeonggi-Do 445-701 (Korea, Republic of)

    2013-09-15T23:59:59.000Z

    Accurate measurement of the strain field in the channels of transistor arrays is critical for strain engineering in modern electronic devices. We applied atomic-resolution high-angle annular dark-field scanning transmission electron microscopy to quantitative measurement of the strain field in transistor arrays. The quantitative strain profile over 20 transistors was obtained with high reliability and a precision of 0.1%. The strain field was found to form homogeneously in the channels of the transistor arrays. Furthermore, strain relaxation due to the thin foil effect was quantitatively investigated for thicknesses of 35 to 275 nm.

  2. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy

    SciTech Connect (OSTI)

    Oberbeck, Lars [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); TOTAL Marketing Services, New Energies, La Défense 10, 92069 Paris La Défense Cedex (France); Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schofield, Steven R. [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, UCL, London WC1E 6BT (United Kingdom); Curson, Neil J., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, UCL, London WC1E 7JE (United Kingdom)

    2014-06-23T23:59:59.000Z

    We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.

  3. Dark Field Microscopy for Analytical Laboratory Courses

    SciTech Connect (OSTI)

    Augspurger, Ashley E.; Stender, Anthony S.; Marchuk, Kyle; Greenbowe, Thomas J.; Fang, Ning

    2014-06-10T23:59:59.000Z

    An innovative and inexpensive optical microscopy experiment for a quantitative analysis or an instrumental analysis chemistry course is described. The students have hands-on experience with a dark field microscope and investigate the wavelength dependence of localized surface plasmon resonance in gold and silver nanoparticles. Students also observe and measure individual crystal growth during a replacement reaction between copper and silver nitrate. The experiment allows for quantitative, qualitative, and image data analyses for undergraduate students.

  4. Scanning electron microscopy of cold gases

    E-Print Network [OSTI]

    Santra, Bodhaditya

    2015-01-01T23:59:59.000Z

    Ultracold quantum gases offer unique possibilities to study interacting many-body quantum systems. Probing and manipulating such systems with ever increasing degree of control requires novel experimental techniques. Scanning electron microscopy is a high resolution technique which can be used for in situ imaging, single site addressing in optical lattices and precision density engineering. Here, we review recent advances and achievements obtained with this technique and discuss future perspectives.

  5. Elements & Compounds Atoms (Elements)

    E-Print Network [OSTI]

    Frey, Terry

    #12;Elements & Compounds #12;Atoms (Elements) Molecules (Compounds) Cells Elements & Compounds #12 #12;First shell Second shell Third shell Hydrogen 1H Lithium 3Li Sodium 11Na Beryllium 4Be Magnesium energy Higher energy (a) A ball bouncing down a flight of stairs provides an analogy for energy levels

  6. Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

    SciTech Connect (OSTI)

    Subhash Chandra

    2008-05-30T23:59:59.000Z

    The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysis of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.

  7. Primary Atomization of a Liquid Jet in Crossflow

    E-Print Network [OSTI]

    Rana, Sandeep

    2010-01-01T23:59:59.000Z

    In this fluid dynamics video, we present a visualization of the primary atomization of a turbulent liquid jet injected into a turbulent gaseous crossflow. It is based on a detailed numerical simulation of the primary atomization region of the jet using a finite volume, balanced force, incompressible LES/DNS flow solver coupled to a Refined Level Set Grid (RLSG) solver to track the phase interface position. The visualization highlights the two distinct breakup modes of the jet: the column breakup mode of the main liquid column and the ligament breakup mode on the sides of the jet and highlights the complex evolution of the phase interface geometry.

  8. Record-Setting Microscopy Illuminates Energy Storage Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Record-Setting Microscopy Illuminates Energy Storage Materials Print X-ray microscopy is powerful in that it can probe large volumes of material at high spatial resolution with...

  9. Flash Scanning Electron Microscopy Raphael Sznitman, Aurelien Lucchi, Marco Cantoni,

    E-Print Network [OSTI]

    Dalang, Robert C.

    Flash Scanning Electron Microscopy Raphael Sznitman, Aurelien Lucchi, Marco Cantoni, Graham Knott. Scanning Electron Microscopy (SEM) is an invaluable tool for biologists and neuroscientists to study brain earlier methods, we explicitly balance the conflicting requirements of spending enough time scanning

  10. Video-rate Scanning Confocal Microscopy and Microendoscopy

    E-Print Network [OSTI]

    Nichols, Alexander J.

    Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical sectioning of complex systems. Confocal microscopy is routinely used, ...

  11. Quantitative imaging of living cells by deep ultraviolet microscopy

    E-Print Network [OSTI]

    Zeskind, Benjamin J

    2006-01-01T23:59:59.000Z

    Developments in light microscopy over the past three centuries have opened new windows into cell structure and function, yet many questions remain unanswered by current imaging approaches. Deep ultraviolet microscopy ...

  12. New Developments in Transmission Electron Microscopy for Nanotechnology**

    E-Print Network [OSTI]

    Wang, Zhong L.

    New Developments in Transmission Electron Microscopy for Nanotechnology** By Zhong Lin Wang* 1. Electron Microscopy and Nanotechnology Nanotechnology, as an international initiative for science manufacturing are the foundation of nanotechnology. Tracking the historical background of why nanotechnology

  13. Atom-by-atom nucleation and growth of graphene nanopores

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Atom-by-atom nucleation and growth of graphene nanopores Christopher J. Russoa,b and J. A February 17, 2012 (received for review December 9, 2011) Graphene is an ideal thin membrane substrate structures in graphene with atomic preci- sion. It consists of inducing defect nucleation centers with ener

  14. Chemically-selective imaging of brain structures with CARS microscopy

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    Chemically-selective imaging of brain structures with CARS microscopy Conor L. Evans1§ , Xiaoyin Xu anti-Stokes Raman scattering (CARS) microscopy to image brain structure and pathology ex vivo. Although. Definitive diagnosis still requires brain biopsy in a significant number of cases. CARS microscopy

  15. Variational Scheme to Compute Protein Reaction Pathways using Atomistic Force Fields with Explicit Solvent

    E-Print Network [OSTI]

    S. a Beccara; L. Fant; P. Faccioli

    2015-02-18T23:59:59.000Z

    We introduce a variational approximation to the microscopic dynamics of rare conformational transitions of macromolecules. Within this framework it is possible to simulate on a small computer cluster reactions as complex as protein folding, using state of the art all-atom force fields in explicit solvent. We test this method against molecular dynamics (MD) simulations of the folding of an alpha- and a beta-protein performed with the same all-atom force field on the Anton supercomputer. We find that our approach yields results consistent with those of MD simulations, at a computational cost orders of magnitude smaller.

  16. Atomic phenomena in dense plasmas

    SciTech Connect (OSTI)

    Weisheit, J.C.

    1981-03-01T23:59:59.000Z

    The following chapters are included: (1) the plasma environment, (2) perturbations of atomic structure, (3) perturbations of atomic collisions, (4) formation of spectral lines, and (5) dielectronic recombination. (MOW)

  17. Dynamic Force AFM (Asylum) | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    specifically for biological applications and can be used to: Study individual protein or DNA molecules in situ Image the surface of living cells Measure the adhesive forces of...

  18. Continuous Forcing Data, Darwin, Australia

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jakob, Christian

    Long term, large scale continuous forcing data set for three complete wet seasons (2004-2005, 2005-2006 and 2006-2007) in Darwin, Australia.

  19. Scanning electron microscopy of intestinal villous structures

    E-Print Network [OSTI]

    Boyer, Edmond

    briefly in running water for 30 minutes and were dehydrated through graded ethanol series (1 hour each in 50, 70, 80, 95 and 100 %). Dehydrated specimens were dried in a carbon dioxide critical point drier to avoid exposure of the specimens to any surface tension forces when drying. The dried specimens were

  20. Physical sectioning in 3D biological microscopy

    E-Print Network [OSTI]

    Guntupalli, Jyothi Swaroop

    2008-10-10T23:59:59.000Z

    ...................................................................... 61 G Stepan’s models of regenerative chatter in metal cutting........................... 62 H Chatter model for KESM............................................................................ 64 ix CHAPTER Page I Summary... based on the source of vibration: frictional, regenerative, mode-coupling, and thermo-mechanical [7]. Frictional chatter gets its excitation energy from the friction force either between the workpiece and the tool 15 flank, or between the section...

  1. Physical sectioning in 3D biological microscopy

    E-Print Network [OSTI]

    Guntupalli, Jyothi Swaroop

    2009-05-15T23:59:59.000Z

    ...................................................................... 61 G Stepan?s models of regenerative chatter in metal cutting........................... 62 H Chatter model for KESM............................................................................ 64 ix CHAPTER Page I Summary... based on the source of vibration: frictional, regenerative, mode-coupling, and thermo-mechanical [7]. Frictional chatter gets its excitation energy from the friction force either between the workpiece and the tool 15 flank, or between the section...

  2. Sub-microsecond-resolution probe microscopy

    DOE Patents [OSTI]

    Ginger, David; Giridharagopal, Rajiv; Moore, David; Rayermann, Glennis; Reid, Obadiah

    2014-04-01T23:59:59.000Z

    Methods and apparatus are provided herein for time-resolved analysis of the effect of a perturbation (e.g., a light or voltage pulse) on a sample. By operating in the time domain, the provided method enables sub-microsecond time-resolved measurement of transient, or time-varying, forces acting on a cantilever.

  3. HRTEM Imaging of Atoms at Sub-Angstrom Resolution

    SciTech Connect (OSTI)

    O'Keefe, Michael A.; Allard, Lawrence F.; Blom, Douglas A.

    2005-04-06T23:59:59.000Z

    John Cowley and his group at Arizona State University pioneered the use of transmission electron microscopy (TEM) for high-resolution imaging. Images were achieved three decades ago showing the crystal unit cell content at better than 4 Angstrom resolution. This achievement enabled researchers to pinpoint the positions of heavy atom columns within the unit cell. Lighter atoms appear as resolution is improved to sub-Angstrom levels. Currently, advanced microscopes can image the columns of the light atoms (carbon, oxygen, nitrogen) that are present in many complex structures, and even the lithium atoms present in some battery materials. Sub-Angstrom imaging, initially achieved by focal-series reconstruction of the specimen exit surface wave, will become common place for next-generation electron microscopes with CS-corrected lenses and monochromated electron beams. Resolution can be quantified in terms of peak separation and inter-peak minimum, but the limits imposed on the attainable resolution by the properties of the micro-scope specimen need to be considered. At extreme resolution the ''size'' of atoms can mean that they will not be resolved even when spaced farther apart than the resolution of the microscope.

  4. atoms: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  5. Calibration of a single atom detector for atomic micro chips

    E-Print Network [OSTI]

    A. Stibor; S. Kraft; T. Campey; D. Komma; A. Günther; J. Fortágh; C. J. Vale; H. Rubinsztein-Dunlop; C. Zimmermann

    2007-02-13T23:59:59.000Z

    We experimentally investigate a scheme for detecting single atoms magnetically trapped on an atom chip. The detector is based on the photoionization of atoms and the subsequent detection of the generated ions. We describe the characterization of the ion detector with emphasis on its calibration via the correlation of ions with simultaneously generated electrons. A detection efficiency of 47.8% (+-2.6%) is measured, which is useful for single atom detection, and close to the limit allowing atom counting with sub-Poissonian uncertainty.

  6. A microfabricated atomic clock

    SciTech Connect (OSTI)

    Knappe, Svenja; Shah, Vishal; Schwindt, Peter D.D.; Hollberg, Leo; Kitching, John; Liew, Li-Anne; Moreland, John [Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States); Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States)

    2004-08-30T23:59:59.000Z

    Fabrication techniques usually applied to microelectromechanical systems (MEMS) are used to reduce the size and operating power of the core physics assembly of an atomic clock. With a volume of 9.5 mm{sup 3}, a fractional frequency instability of 2.5x10{sup -10} at 1 s of integration, and dissipating less than 75 mW of power, the device has the potential to bring atomically precise timing to hand-held, battery-operated devices. In addition, the design and fabrication process allows for wafer-level assembly of the structures, enabling low-cost mass-production of thousands of identical units with the same process sequence, and easy integration with other electronics.

  7. Delay in Atomic Photoionization

    SciTech Connect (OSTI)

    Kheifets, A. S. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106-4030 (United States); Ivanov, I. A. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia)

    2010-12-03T23:59:59.000Z

    We analyze the time delay between emission of photoelectrons from the outer valence ns and np subshells in noble gas atoms following absorption of an attosecond extreme ultraviolet pulse. Various processes such as elastic scattering of the photoelectron on the parent ion and many-electron correlation affect the apparent 'time zero' when the photoelectron leaves the atom. This qualitatively explains the time delay between photoemission from the 2s and 2p subshells of Ne as determined experimentally by attosecond streaking [Science 328, 1658 (2010)]. However, with our extensive numerical modeling, we were only able to account for less than half of the measured time delay of 21{+-}5 as. We argue that the extreme ultraviolet pulse alone cannot produce such a large time delay and it is the streaking IR field that is most likely responsible for this effect.

  8. Fast electron microscopy via compressive sensing

    DOE Patents [OSTI]

    Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

    2014-12-09T23:59:59.000Z

    Various technologies described herein pertain to compressive sensing electron microscopy. A compressive sensing electron microscope includes a multi-beam generator and a detector. The multi-beam generator emits a sequence of electron patterns over time. Each of the electron patterns can include a plurality of electron beams, where the plurality of electron beams is configured to impart a spatially varying electron density on a sample. Further, the spatially varying electron density varies between each of the electron patterns in the sequence. Moreover, the detector collects signals respectively corresponding to interactions between the sample and each of the electron patterns in the sequence.

  9. New Microscopy Patent Awarded | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparency VisitSilverNephelineNeuralNewIdeasofNew Microscopy Patent

  10. Air Force Enhanced Use Lease

    Broader source: Energy.gov (indexed) [DOE]

    S e r v i c e - E x c e l l e n c e Headquarters U.S. Air Force 1 Air Force Enhanced Use Lease Mr. Brian Brown 16 Oct. 12 I n t e g r i t y - S e r v i c e - E x c e l l e n c e 2...

  11. Air Force Renewable Energy Programs

    Broader source: Energy.gov (indexed) [DOE]

    in All We Do" I n t e g r i t y - S e r v i c e - E x c e l l e n c e THINK GREEN, BUILD GREEN, Topics Air Force Energy Use Air Force Facility Energy Center Current RE...

  12. Backaction-Driven Transport of Bloch Oscillating Atoms in Ring Cavities

    E-Print Network [OSTI]

    J. Goldwin; B. Prasanna Venkatesh; D. H. J. O'Dell

    2014-08-19T23:59:59.000Z

    We predict that an atomic Bose-Einstein condensate strongly coupled to an intracavity optical lattice can undergo resonant tunneling and directed transport when a constant and uniform bias force is applied. The bias force induces Bloch oscillations, causing amplitude and phase modulation of the lattice which resonantly modifies the site-to-site tunneling. For the right choice of parameters a net atomic current is generated. The transport velocity can be oriented oppositely to the bias force, with its amplitude and direction controlled by the detuning between the pump laser and the cavity. The transport can also be enhanced through imbalanced pumping of the two counter-propagating running wave cavity modes. Our results add to the cold atoms quantum simulation toolbox, with implications for quantum sensing and metrology.

  13. Optics and interferometry with atoms and molecules

    E-Print Network [OSTI]

    Cronin, Alexander D.

    Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic ...

  14. Thin polymer films of block copolymers and blend/nanoparticle composites 

    E-Print Network [OSTI]

    Kalloudis, Michail

    2013-11-28T23:59:59.000Z

    In this thesis, atomic force microscopy (AFM), transmission electron microscopy (TEM) and optical microscopy techniques were used to investigate systematically the self-assembled nanostructure behaviour of two different ...

  15. Multifunctional Composites and Devices for Sensing and Energy Harvesting 

    E-Print Network [OSTI]

    Cleveland, Michael Allen

    2011-08-08T23:59:59.000Z

    melting method, the magenetocaloric samples were created. Multi-length scales characterized using atomic force microscopy (AFM), optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-Ray diffraction (XRD...

  16. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumni AlumniFederalAshley BoyleAn overhead viewAtom-split it

  17. Direct visualization of atomically precise nitrogen-doped graphene nanoribbons

    SciTech Connect (OSTI)

    Zhang, Yi; Zhang, Yanfang; Li, Geng; Lu, Jianchen; Du, Shixuan, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Gao, Hong-Jun [Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China); Lin, Xiao [University of Chinese Academy of Sciences and Institute of Physics, Chinese Academy of Sciences, Beijing 100049 (China); Berger, Reinhard; Feng, Xinliang, E-mail: sxdu@iphy.ac.cn, E-mail: feng@mpip-mainz.mpg.de; Müllen, Klaus [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)

    2014-07-14T23:59:59.000Z

    We have fabricated atomically precise nitrogen-doped chevron-type graphene nanoribbons by using the on-surface synthesis technique combined with the nitrogen substitution of the precursors. Scanning tunneling microscopy and spectroscopy indicate that the well-defined nanoribbons tend to align with the neighbors side-by-side with a band gap of 1.02?eV, which is in good agreement with the density functional theory calculation result. The influence of the high precursor coverage on the quality of the nanoribbons is also studied. We find that graphene nanoribbons with sufficient aspect ratios can only be fabricated at sub-monolayer precursor coverage. This work provides a way to construct atomically precise nitrogen-doped graphene nanoribbons.

  18. Single Molecule DNA Detection with an Atomic Vapor Notch Filter

    E-Print Network [OSTI]

    Uhland, Denis; Widmann, Matthias; Lee, Sang-Yun; Wrachtrup, Jörg; Gerhardt, Ilja

    2015-01-01T23:59:59.000Z

    The detection of single molecules has facilitated many advances in life- and material-sciences. Commonly, it founds on the fluorescence detection of single molecules, which are for example attached to the structures under study. For fluorescence microscopy and sensing the crucial parameters are the collection and detection efficiency, such that photons can be discriminated with low background from a labeled sample. Here we show a scheme for filtering the excitation light in the optical detection of single stranded labeled DNA molecules. We use the narrow-band filtering properties of a hot atomic vapor to filter the excitation light from the emitted fluorescence of a single emitter. The choice of atomic sodium allows for the use of fluorescent dyes, which are common in life-science. This scheme enables efficient photon detection, and a statistical analysis proves an enhancement of the optical signal of more than 15% in a confocal and in a wide-field configuration.

  19. Le magn)sme ar)ficiel pour les gaz d'atomes froids

    E-Print Network [OSTI]

    Dalibard, Jean

    Le magné)sme ar)ficiel pour les gaz d'atomes froids Jean Dalibard Année 2013-14 Chaire Atomes et rayonnement #12;Thème général du cours : le magné?sme = q v B = 0 perdu d'avance ? pas forcément... On peut émuler ce magné?sme par

  20. Spectra of helium clusters with up to six atoms using soft core potentials

    E-Print Network [OSTI]

    M. Gattobigio; A. Kievsky; M. Viviani

    2011-12-01T23:59:59.000Z

    In this work we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with $A=2,3,4,5,6$ atoms with an inter-particle potential which does not present a strong repulsion at short distances. We use an attractive gaussian potential that reproduces the values of the dimer binding energy, the atom-atom scattering length, and the effective range obtained with one of the widely used He-He interactions, the LM2M2 potential. In systems with more than two atoms we consider a repulsive three-body force that, by construction, reproduces the trimer binding energy of the LM2M2 potential. With this model, consisting in the sum of a two- and three-body potential, we have calculated the spectrum of clusters formed by four, five and six helium atoms. We have found that these systems present two bound states, one deep and one shallow close to the threshold fixed by the energy of the $(A-1)$-atom system. Universal relations between the energies of the excited state of the $A$-atom system and the ground state energy of the $(A-1)$-atom system are extracted as well as the ratio between the ground state of the $A$-atom system and the ground state energy of the trimer.

  1. Spectra of helium clusters with up to six atoms using soft-core potentials

    SciTech Connect (OSTI)

    Gattobigio, M. [Universite de Nice-Sophia Antipolis, Institut Non-Lineaire de Nice, CNRS, 1361 route des Lucioles, F-06560 Valbonne (France); Kievsky, A.; Viviani, M. [Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100 Pisa (Italy)

    2011-11-15T23:59:59.000Z

    In this paper, we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with A=2,3,4,5,6 atoms with an interparticle potential which does not present a strong repulsion at short distances. We use an attractive Gaussian potential that reproduces the values of the dimer binding energy, the atom-atom scattering length, and the effective range obtained with one of the widely used He-He interactions, the Aziz and Slaman potential, called LM2M2. In systems with more than two atoms, we consider a repulsive three-body force that, by construction, reproduces the trimer binding energy of the LM2M2 potential. With this model, consisting of the sum of a two- and three-body potential, we have calculated the spectrum of clusters formed by four, five, and six helium atoms. We have found that these systems present two bound states, one deep and one shallow, close to the threshold fixed by the energy of the (A-1)-atom system. Universal relations between the energies of the excited state of the A-atom system and the ground-state energy of the (A-1)-atom system are extracted, as well as the ratio between the ground state of the A-atom system and the ground-state energy of the trimer.

  2. Atomic Energy Commission Takes Over Responsibility for all Atomic...

    National Nuclear Security Administration (NNSA)

    Takes Over Responsibility for all Atomic Energy Programs | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile...

  3. Dynamics of Cell Shape and Forces on Micropatterned Substrates Predicted by a Cellular Potts Model

    E-Print Network [OSTI]

    Philipp J. Albert; Ulrich S. Schwarz

    2014-05-19T23:59:59.000Z

    Micropatterned substrates are often used to standardize cell experiments and to quantitatively study the relation between cell shape and function. Moreover, they are increasingly used in combination with traction force microscopy on soft elastic substrates. To predict the dynamics and steady states of cell shape and forces without any a priori knowledge of how the cell will spread on a given micropattern, here we extend earlier formulations of the two-dimensional cellular Potts model. The third dimension is treated as an area reservoir for spreading. To account for local contour reinforcement by peripheral bundles, we augment the cellular Potts model by elements of the tension-elasticity model. We first parameterize our model and show that it accounts for momentum conservation. We then demonstrate that it is in good agreement with experimental data for shape, spreading dynamics, and traction force patterns of cells on micropatterned substrates. We finally predict shapes and forces for micropatterns that have not yet been experimentally studied.

  4. Quantum transport in ultracold atoms

    E-Print Network [OSTI]

    Chih-Chun Chien; Sebastiano Peotta; Massimiliano Di Ventra

    2015-04-11T23:59:59.000Z

    Ultracold atoms confined by engineered magnetic or optical potentials are ideal systems for studying phenomena otherwise difficult to realize or probe in the solid state because their atomic interaction strength, number of species, density, and geometry can be independently controlled. This review focuses on quantum transport phenomena in atomic gases that mirror and oftentimes either better elucidate or show fundamental differences with those observed in mesoscopic and nanoscopic systems. We discuss significant progress in performing transport experiments in atomic gases, contrast similarities and differences between transport in cold atoms and in condensed matter systems, and survey inspiring theoretical predictions that are difficult to verify in conventional setups. These results further demonstrate the versatility offered by atomic systems in the study of nonequilibrium phenomena and their promise for novel applications.

  5. Protective Force Firearms Qualification Courses

    Broader source: Energy.gov (indexed) [DOE]

    points; Protective Force Firearms Qualification Courses Section A Appendix 4 July 2011 4-3 d. a projectile print within or cutting the outer ring is 2 points; and e. a projectile...

  6. Prediction of vehicle impact forces

    E-Print Network [OSTI]

    Kaderka, Darrell Laine

    1990-01-01T23:59:59.000Z

    PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject...: Civil Engineering PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Approved as to style and content by: C. Eugene Buth (Chair of Committee) W. ynn Beason (Member) I? D n E. B ay (Member) es T. P. Yao (Departmen Head) May...

  7. Prediction of vehicle impact forces 

    E-Print Network [OSTI]

    Kaderka, Darrell Laine

    1990-01-01T23:59:59.000Z

    PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1990 Major Subject...: Civil Engineering PREDICTION OF VEHICLE IMPACT FORCES A Thesis by DARRELL LAINE KADERKA Approved as to style and content by: C. Eugene Buth (Chair of Committee) W. ynn Beason (Member) I? D n E. B ay (Member) es T. P. Yao (Departmen Head) May...

  8. Direct imaging of crystal structure and defects in metastable Ge{sub 2}Sb{sub 2}Te{sub 5} by quantitative aberration-corrected scanning transmission electron microscopy

    SciTech Connect (OSTI)

    Ross, Ulrich; Lotnyk, Andriy, E-mail: andriy.lotnyk@iom-leipzig.de; Thelander, Erik; Rauschenbach, Bernd [Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig (Germany)

    2014-03-24T23:59:59.000Z

    Knowledge about the atomic structure and vacancy distribution in phase change materials is of foremost importance in order to understand the underlying mechanism of fast reversible phase transformation. In this Letter, by combining state-of-the-art aberration-corrected scanning transmission electron microscopy with image simulations, we are able to map the local atomic structure and composition of a textured metastable Ge{sub 2}Sb{sub 2}Te{sub 5} thin film deposited by pulsed laser deposition with excellent spatial resolution. The atomic-resolution scanning transmission electron microscopy investigations display the heterogeneous defect structure of the Ge{sub 2}Sb{sub 2}Te{sub 5} phase. The obtained results are discussed. Highly oriented Ge{sub 2}Sb{sub 2}Te{sub 5} thin films appear to be a promising approach for further atomic-resolution investigations of the phase change behavior of this material class.

  9. Testing Gravity with Cold-Atom Interferometers

    E-Print Network [OSTI]

    G. W. Biedermann; X. Wu; L. Deslauriers; S. Roy; C. Mahadeswaraswamy; M. A. Kasevich

    2014-12-10T23:59:59.000Z

    We present a horizontal gravity gradiometer atom interferometer for precision gravitational tests. The horizontal configuration is superior for maximizing the inertial signal in the atom interferometer from a nearby proof mass. In our device, we have suppressed spurious noise associated with the horizonal configuration to achieve a differential acceleration sensitivity of 4.2$\\times10^{-9}g/\\sqrt{Hz}$ over a 70 cm baseline or 3.0$\\times10^{-9}g/\\sqrt{Hz}$ inferred per accelerometer. Using the performance of this instrument, we characterize the results of possible future gravitational tests. We complete a proof-of-concept measurement of the gravitational constant with a precision of 3$\\times10^{-4}$ that is competitive with the present limit of 1.2$\\times10^{-4}$ using other techniques. From this measurement, we provide a statistical constraint on a Yukawa-type fifth force at 8$\\times$10$^{-3}$ near the poorly known length scale of 10 cm. Limits approaching 10$^{-5}$ appear feasible. We discuss improvements that can enable uncertainties falling well below 10$^{-5}$ for both experiments.

  10. String model of the Hydrogen Atom

    E-Print Network [OSTI]

    Omar Yepez

    2007-01-31T23:59:59.000Z

    A non-moving electron hydrogen model is proposed, resolving a long standing contradiction (94 years) in the hydrogen atom. This, however, forces to not use the "in an orbit point particle kinetic energy" as the phenomenon responsible for the atom stability. The repulsion between the masses of the electron and proton is what is responsible of such stability. The mass of the electron is a field fully described by the uncertainty principle through the confinement of the particle, which is also consistent with the general theory of relativity that states: "mass-energy tells the space how to bend". Ergo, mass exerts a tension on its surrounding space and the lighter the mass the larger the space it will occupy. Based on this concept it is proposed that the orbital is the electron. The electron's orbitals are just the electron's different ways of intersecting the space; with different magnetic momenta. The coupling of this momenta with the magnetic moment of the proton finally explains the hyperfine structure of the hydrogen spectrum with an overwhelming simplicity

  11. In-Situ Transmission Electron Microscopy Probing of Native Oxide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing of Native Oxide and Artificial Layers on Silicon Nanoparticles for Lithium Ion In-Situ Transmission Electron Microscopy Probing of Native Oxide and Artificial...

  12. NATIONAL CENTRE FOR SENSOR RESEARCH (NCSR) Research Engineer Fluorescence Microscopy

    E-Print Network [OSTI]

    Humphrys, Mark

    manuals, prepare standard operating procedures and ensure documentation is maintained. · Manage online projects. · Undertake the commissioning and maintenance of microscopy equipment. · Collate operations

  13. In-Situ Electron Microscopy of Electrical Energy Storage Materials...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Storage Materials In-Situ Electron Microscopy of Electrical Energy Storage Materials In-situ characterization and diagnostics of mechanical degradation in electrodes...

  14. Strong wind forcing of the ocean

    E-Print Network [OSTI]

    Zedler, Sarah E.

    2007-01-01T23:59:59.000Z

    latitudes, tropical storm force winds may be sufficient tolocation where hurricane force winds arrive at the region.shear data. The wind stress used to force these model was

  15. Light-induced gauge fields for ultracold atoms

    E-Print Network [OSTI]

    N. Goldman; G. Juzeliunas; P. Ohberg; I. B. Spielman

    2014-12-12T23:59:59.000Z

    Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our universe is ruled by gravity, whose gauge structure suggests the existence of a particle - the graviton - that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms "feeling" laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials - both Abelian and non-Abelian - in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.

  16. Spin-Flavor van der Waals Forces and NN interaction

    SciTech Connect (OSTI)

    Alvaro Calle Cordon, Enrique Ruiz Arriola

    2011-12-01T23:59:59.000Z

    A major goal in Nuclear Physics is the derivation of the Nucleon-Nucleon (NN) interaction from Quantum Chromodynamics (QCD). In QCD the fundamental degrees of freedom are colored quarks and gluons which are confined to form colorless strongly interacting hadrons. Because of this the resulting nuclear forces at sufficiently large distances correspond to spin-flavor excitations, very much like the dipole excitations generating the van der Waals (vdW) forces acting between atoms. We study the Nucleon-Nucleon interaction in the Born-Oppenheimer approximation at second order in perturbation theory including the Delta resonance as an intermediate state. The potential resembles strongly chiral potentials computed either via soliton models or chiral perturbation theory and has a van der Waals like singularity at short distances which is handled by means of renormalization techniques. Results for the deuteron are discussed.

  17. Thermal Issues in Casimir Forces Between Conductors and Semiconductors

    E-Print Network [OSTI]

    K. A. Milton; Iver Brevik; Simen A. Ellingsen

    2012-07-20T23:59:59.000Z

    The Casimir effect between metal surfaces has now been well-verified at the few-percent level experimentally. However, the temperature dependence has never been observed in the laboratory, since all experiments are conducted at room temperature. The temperature dependence for the related Casimir-Polder force between an atom and a bulk material has, in contrast, been observed between a BEC and a silica substrate, with the environment and the silica held at different temperatures. There is a controversy about the temperature dependence for the force between metals, having to do with the magnitude of the linear temperature term for both low and high temperature, the latter being most prominent at large distances. There are also related anomalies pertaining to semiconductors. The status of this controversy, and of the relevant experiments, are reviewed in this report.

  18. Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion

    E-Print Network [OSTI]

    Subhadeep Gupta; Kevin L. Moore; Kater W. Murch; Dan M. Stamper-Kurn

    2007-09-05T23:59:59.000Z

    We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to $10^5$ $^{87}$Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.

  19. The use of atomic level stress to characterize the structure of irradiated iron

    SciTech Connect (OSTI)

    Egami, Takeshi [ORNL] [ORNL; Ojha, Madhusudan [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Nicholson, Donald M. [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Odbadrakh, Khorgolkhuu [ORNL] [ORNL; Radhakrishnan, Bala [ORNL] [ORNL; Stoller, Roger E [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    The behaviour of irradiated material near a primary knock on atom immediately after impact is of great importance for designing reactor materials. Currently, molecular dynamics simulations with classical force fields provide the foundation for understanding the resulting cascade. However, modern density functional calculations can now treat large enough numbers of atoms that they can provide additional details of the magnetic and electronic nature of irradiated samples. In this paper we calculate from first principles the atomic level stresses for an instantaneous configuration following the initiation of a low energy cascade in iron.

  20. Ab-initio friction forces on the nanoscale: A DFT study of fcc Cu(111)

    E-Print Network [OSTI]

    Wolloch, Michael; Mohn, Peter; Redinger, Josef; Vernes, András

    2014-01-01T23:59:59.000Z

    While there are a number of models that tackle the problem of calculating friction forces on the atomic level, providing a completely parameter-free approach remains a challenge. Here we present a quasi-static model to obtain an approximation to the nanofrictional response of dry, wearless systems based on quantum mechanical all-electron calculations. We propose a mechanism to allow dissipative sliding, which relies on atomic relaxations. We define two different ways of calculating the mean nanofriction force, both leading to an exponential friction-versus-load behavior for all sliding directions. Since our approach does not impose any limits on lengths and directions of the sliding paths, we investigate arbitrary sliding directions for an fcc Cu(111) interface and detect two periodic paths which form the upper and lower bound of nanofriction. For long aperiodic paths the friction force convergences to a value in between these limits. For low loads we retrieve the Derjaguin generalization of Amontons-Coulomb ...

  1. Coherent Atom Optics with fast metastable rare gas atoms

    SciTech Connect (OSTI)

    Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Vassilev, G.; Ducloy, M. [Laboratoire de Physique des Lasers, Universite Paris 13, Avenue J.B. Clement, 93430-Villetaneuse (France); Bocvarski, V. [Institute of Physics, Pregrevica 118, 11080 - Belgrade-Zemun (Serbia and Montenegro)

    2006-12-01T23:59:59.000Z

    Coherent atom optics experiments making use of an ultra-narrow beam of fast metastable atoms generated by metastability exchange are reported. The transverse coherence of the beam (coherence radius of 1.7 {mu}m for He*, 1.2 {mu}m for Ne*, 0.87 {mu}m for Ar*) is demonstrated via the atomic diffraction by a non-magnetic 2{mu}m-period reflection grating. The combination of the non-scalar van der Waals (vdW) interaction with the Zeeman interaction generated by a static magnetic field gives rise to ''vdW-Zeeman'' transitions among Zeeman sub-levels. Exo-energetic transitions of this type are observed with Ne*(3P2) atoms traversing a copper micro-slit grating. They can be used as a tunable beam splitter in an inelastic Fresnel bi-prism atom interferometer.

  2. U.S. Air Force Fact Sheet Air Force Reserve Officer Training Corps

    E-Print Network [OSTI]

    Su, Xiao

    U.S. Air Force Fact Sheet Air Force Reserve Officer Training Corps Mission Develop Quality Leaders for the Air Force. Personnel and Resources Air Force Reserve Officer Training Corps (ROTC) includes four,796 new Second Lieutenants who entered active duty in the United States Air Force. Organization Air Force

  3. Forces in electromagnetic field and gravitational field

    E-Print Network [OSTI]

    Zihua Weng

    2011-03-31T23:59:59.000Z

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in the interplanetary space between the sun and the earth.

  4. Field mapping by off-axis electron holography: from devices to the detection of single dopant atoms.

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Field mapping by off-axis electron holography: from devices to the detection of single dopant atoms. 3. Ernst-Ruska Center for Microscopy and Spectroscopy with Electrons, Research Centre Julich, D-52425 Julich, Germany. david.cooper@cea.fr Keywords: electron holography, dopant potentials, strain

  5. Complete information acquisition in scanning probe microscopy

    SciTech Connect (OSTI)

    Belianinov, Alex [ORNL; Kalinin, Sergei V [ORNL; Jesse, Stephen [ORNL

    2015-01-01T23:59:59.000Z

    In the last three decades, scanning probe microscopy (SPM) has emerged as a primary tool for exploring and controlling the nanoworld. A critical part of the SPM measurements is the information transfer from the tip-surface junction to a macroscopic measurement system. This process reduces the many degrees of freedom of a vibrating cantilever to relatively few parameters recorded as images. Similarly, the details of dynamic cantilever response at sub-microsecond time scales of transients, higher-order eigenmodes and harmonics are averaged out by transitioning to millisecond time scale of pixel acquisition. Hence, the amount of information available to the external observer is severely limited, and its selection is biased by the chosen data processing method. Here, we report a fundamentally new approach for SPM imaging based on information theory-type analysis of the data stream from the detector. This approach allows full exploration of complex tip-surface interactions, spatial mapping of multidimensional variability of material s properties and their mutual interactions, and SPM imaging at the information channel capacity limit.

  6. Bogoliubov theory and bosonic atoms

    E-Print Network [OSTI]

    Phan Thanh Nam

    2011-09-13T23:59:59.000Z

    We formulate the Bogoliubov variational principle in a mathematical framework similar to the generalized Hartree-Fock theory. Then we analyze the Bogoliubov theory for bosonic atoms in details. We discuss heuristically why the Bogoliubov energy should give the first correction to the leading energy of large bosonic atoms.

  7. In-situ control system for atomization

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Terpstra, R.L.

    1995-06-13T23:59:59.000Z

    Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray is disclosed. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray. 3 figs.

  8. Comparison of Segmentation Algorithms For Fluorescence Microscopy Images of Cells

    E-Print Network [OSTI]

    Bernal, Javier

    - mentation techniques are less accurate than k-means clustering with multiple clusters. Segmentation accuracy fluorescence microscopy; k-means cluster; image segmentation; cell edge; bivariate simi- larity index NUMEROUSComparison of Segmentation Algorithms For Fluorescence Microscopy Images of Cells Alden A. Dima,1

  9. Photoacoustic microscopy of tyrosinase reporter gene in vivo

    E-Print Network [OSTI]

    Wang, Lihong

    Photoacoustic microscopy of tyrosinase reporter gene in vivo Arie Krumholz Sarah J. Van microscopy of tyrosinase reporter gene in vivo Arie Krumholz,a Sarah J. VanVickle-Chavez,b Junjie Yao for tyrosinase, the primary enzyme responsible for expression of melanin in melanogenic cells. Optical res

  10. Spectral Emission of Moving Atom

    E-Print Network [OSTI]

    J. X. Zheng-Johansson

    2008-03-17T23:59:59.000Z

    A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the spectral emission of a moving atom exhibits always a redshift which informs not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a portion of its internal energy on transiting to a lower-energy state which however has in a moving atom an additional energy gain; this results in a redshift in the emission frequency. Based on auxiliary experimental information and a scheme for de Broglie particle formation, we give a vigorous elucidation of the mechanism for deceleration radiation of atomic electron; the corresponding prediction of the redshift is in complete agreement with the Ives and Stilwell's experimental formula.

  11. Supersonic coal water slurry fuel atomizer

    DOE Patents [OSTI]

    Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA); Balsavich, John (Foxborough, MA)

    1991-01-01T23:59:59.000Z

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  12. Nuclear force in Lattice QCD

    E-Print Network [OSTI]

    T. T. Takahashi; T. Doi; H. Suganuma

    2006-01-05T23:59:59.000Z

    We perform the quenched lattice QCD analysis on the nuclear force (baryon-baryon interactions). We employ $20^3\\times 24$ lattice at $\\beta=5.7$ ($a\\simeq 0.19$ fm) with the standard gauge action and the Wilson quark action with the hopping parameters $\\kappa=0.1600, 0.1625, 0.1650$, and generate about 200 gauge configurations. We measure the temporal correlators of the two-baryon system which consists of heavy-light-light quarks. We extract the inter-baryon force as a function of the relative distance $r$. We also evaluate the contribution to the nuclear force from each ``Feynman diagram'' such as the quark-exchange diagram individually, and single out the roles of Pauli-blocking effects or quark exchanges in the inter-baryon interactions.

  13. Forcing in Strategic Belief Models

    E-Print Network [OSTI]

    Tohmè, Fernando; Gangle, Rocco

    2012-01-01T23:59:59.000Z

    Forcing is a methodology for building models of Set Theory satisfying certain properties. Since its inception by Paul Cohen, in the early 1960s, it has been applied to several areas in Mathematical Logic, becoming a powerful tool in the analysis of axiomatic systems. In this paper we extend the applicability of forcing to game-theoretic strategic belief models. In particular, we propose a very general notion of solutions for such games by enlarging Brandenburger's $RmAR$ condition via extension through generic types.

  14. Automatic HTS force measurement instrument

    DOE Patents [OSTI]

    Sanders, Scott T. (Valparaiso, IN); Niemann, Ralph C. (Downers Grove, IL)

    1999-01-01T23:59:59.000Z

    A device for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed.

  15. Automatic HTS force measurement instrument

    DOE Patents [OSTI]

    Sanders, S.T.; Niemann, R.C.

    1999-03-30T23:59:59.000Z

    A device is disclosed for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed. 3 figs.

  16. Atomization and Sprays 20(4), 297310 (2010) SPLASHING PHENOMENA DURING LIQUID

    E-Print Network [OSTI]

    Aguilar, Guillermo

    sound speed in liquid, m/s Tsat saturation temperature of droplet at 1 atm, C F force, N V droplet number (V µ/) tc characteristic spreading time, s Cg sound speed in ambient gas, m/s T temperature, C ClAtomization and Sprays 20(4), 297­310 (2010) SPLASHING PHENOMENA DURING LIQUID DROPLET IMPACT Jie

  17. Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux

    E-Print Network [OSTI]

    Rioux, Frank

    Critique of the Centrifugal Effect in the Hydrogen Atom Frank Rioux Some quantum textbooks invoke with involves the middle term in the Hamiltonian given above. Some authors call it the centrifugal potential the effective potential energy. In support of this maneuver they invoke the idea of centrifugal force, which

  18. Measuring biomolecules: an image processing and length estimation pipeline using atomic

    E-Print Network [OSTI]

    Mohri, Mehryar

    Measuring biomolecules: an image processing and length estimation pipeline using atomic force, these snapshots would give direct, specific observation of the cell's regulation behavior. Taking a snapshot estimation pipeline using AFM that can achieve these measurement tolerances. In particular, we developed

  19. 1996, Journal of Microscopy 181, 225-237 (and vol 182, p 240.) Multimodal microscopy by digital image processing

    E-Print Network [OSTI]

    Stone, J. V.

    , Blakistone and Kyryk 1990 compared applications of polarised light, bright eld, DIC and scanning electron microscopy SEM in the paper industry. Fluorescence microscopy adds further possible imaging modes to light. 1 #12;1 Introduction Di erent imaging modes with the light microscope convey complementary infor

  20. Solvent-induced forces in protein folding

    SciTech Connect (OSTI)

    Ben-Naim, A. (Hebrew Univ., Jerusalem (Israel))

    1990-08-23T23:59:59.000Z

    The solvent-induced forces between various groups on the protein are examined. It is found that the intramolecular hydrophilic forces are likely to be the strongest forces mediated through the solvent. It is argued that these are probably the most important solvent-induced driving forces in the process of protein folding.

  1. October 9, 2014- SEAB Task Force Meeting

    Broader source: Energy.gov [DOE]

    SECRETARY OF ENERGY ADVISORY BOARDTask Force Meeting on Technology Development for Environmental Management (EM)

  2. Nanoscale Optical Devices: Force, Torque and Modulator

    E-Print Network [OSTI]

    Liu, Ming

    2010-01-01T23:59:59.000Z

    enhancements produced by a bowtie (Butterworth Heinemann,stronger binding forces. For bowtie structures, the field

  3. High-resolution ab initio three-dimensional x-ray diffraction microscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; Noy, Aleksandr; Hau-Riege, Stefan P.; Cui, Congwu; Howells, Malcolm R.; Rosen, Rachel; He, Haifeng; Spence, John C.; et al

    2006-01-01T23:59:59.000Z

    Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatialmore »resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.« less

  4. Hetero-epitaxial EuO interfaces studied by analytic electron microscopy

    SciTech Connect (OSTI)

    Mundy, Julia A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Hodash, Daniel; Melville, Alexander; Held, Rainer [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Mairoser, Thomas; Schmehl, Andreas [Zentrum für Elektronische Korrelationen und Magnetismus, Universität Augsburg, Universitätsstraße 1, D-86159 Augsburg (Germany); Muller, David A.; Kourkoutis, Lena F. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853 (United States); Schlom, Darrell G. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853 (United States)

    2014-03-03T23:59:59.000Z

    With nearly complete spin polarization, the ferromagnetic semiconductor europium monoxide could enable next-generation spintronic devices by providing efficient ohmic spin injection into silicon. Spin injection is greatly affected by the quality of the interface between the injector and silicon. Here, we use atomic-resolution scanning transmission electron microscopy in conjunction with electron energy loss spectroscopy to directly image and chemically characterize a series of EuO|Si and EuO|YAlO{sub 3} interfaces fabricated using different growth conditions. We identify the presence of europium silicides and regions of disorder at the EuO|Si interfaces, imperfections that could significantly reduce spin injection efficiencies via spin-flip scattering.

  5. High-resolution ab initio Three-dimensional X-ray Diffraction Microscopy

    SciTech Connect (OSTI)

    Chapman, H N; Barty, A; Marchesini, S; Noy, A; Cui, C; Howells, M R; Rosen, R; He, H; Spence, J H; Weierstall, U; Beetz, T; Jacobsen, C; Shapiro, D

    2005-08-19T23:59:59.000Z

    Coherent X-ray diffraction microscopy is a method of imaging non-periodic isolated objects at resolutions only limited, in principle, by the largest scattering angles recorded. We demonstrate X-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the 3D diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a non-periodic object. We also construct 2D images of thick objects with infinite depth of focus (without loss of transverse spatial resolution). These methods can be used to image biological and materials science samples at high resolution using X-ray undulator radiation, and establishes the techniques to be used in atomic-resolution ultrafast imaging at X-ray free-electron laser sources.

  6. High-resolution ab initio three-dimensional x-ray diffraction microscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; Noy, Aleksandr; Hau-Riege, Stefan P.; Cui, Congwu; Howells, Malcolm R.; Rosen, Rachel; He, Haifeng; Spence, John C.; Weierstall, Uwe; Beetz, Tobias; Jacobsen, Chris; Shapiro, David

    2006-01-01T23:59:59.000Z

    Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatial resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.

  7. Detection of transient fluorine atoms

    SciTech Connect (OSTI)

    Loge, G.W.; Nereson, N.; Fry, H.A.

    1986-01-01T23:59:59.000Z

    A KrF eximer laser with a fluence of 50 mJ/cm/sup 2/ was used to photolyze either uranium hexafluoride or molecular fluorine, yielding a transient number density of fluorine atoms. The rise and decay of the atomic fluorine density was observed by transient absorption of a 25-..mu..m Pb-salt diode laser. To prevent the diode laser wavelength from drifting out of resonance with the atomic fluorine line, part of the beam was split off and sent through a microwave discharge fluorine atom cell. This allowed a wavelength modulation-feedback technique to be used to lock the diode laser wavelength onto the atomic line. The remaining diode laser beam was made collinear with the eximer laser beam using a LiF window with a 45/sup 0/ angle of incidence to reflect the infrared beam while transmitting most of the uv beam. Using this setup along with a transient digitizer to average between 100 and 200 transient absorption profiles, fluorine atom number densities on the order of 10/sup 14/ cm/sup -3/ in a 1.7 m pathlength were detected. The signals observed were about a factor of two less than expected from known photolysis and atomic fluorine absorption cross-sections. 2 refs., 4 figs.

  8. Largely defocused probe scanning transmission electron microscopy for imaging local modulation of strain field in a hetero interface

    SciTech Connect (OSTI)

    Kim, Suhyun, E-mail: u98kim@surface.phys.titech.ac.jp; Jung, Younheum; Kim, Joong Jung; Lee, Sunyoung; Lee, Haebum [Memory Analysis Science and Engineering Group, Samsung Electronics, San #16 Hwasung-City, Gyeonggi-Do 445-701 (Korea, Republic of); Oshima, Yoshifumi [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan)

    2014-10-13T23:59:59.000Z

    We present an innovative method for characterizing the strain field in three dimensions in a hetero interface. Largely defocused probe scanning transmission electron microscopy (LDP-STEM) was employed for imaging the inhomogeneous strain field in a germanium (Ge) layer deposited on a silicon (Si) substrate. In the LDP-STEM image, Ge-atomic columns that are relaxed or strained to the Si substrate in the Si/Ge hetero interface were observed to be distinguishable, allowing for the qualitative characterization of the coherency of the crystal growth. Our results revealed that the strain field is locally modulated along the in-plane direction in the Si/Ge hetero interface.

  9. Anticipating the atom: popular perceptions of atomic power before Hiroshima

    E-Print Network [OSTI]

    d'Emal, Jacques-Andre Christian

    1994-01-01T23:59:59.000Z

    Before Hiroshima made the Bomb an object of popular concern, possible implications and applications of atomic physics had been discussed in the public forum. The new science of X-rays and radium promised the possibilities of unlimited energy...

  10. atomization atomic absorption: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in vacuum. The...

  11. Constraints on New Gravitylike Forces in the Nanometer Range

    E-Print Network [OSTI]

    Kamiya, Y; Tani, M; Kim, G N; Komamiya, S

    2015-01-01T23:59:59.000Z

    We report on a new constraint on gravitylike short-range forces, in which the interaction charge is mass, obtained by measuring the angular distribution of 5 A neutrons scattering off atomic xenon gas. Around 10^7 scattering events were collected at the 40 m small angle neutron scattering beam line located at the HANARO research reactor of the Korean Atomic Energy Research Institute. The extracted coupling strengths of new forces in the Yukawa-type parametrization are g^2 = (0.2 \\pm 6.8 \\pm 2.0) \\times 10^-15 GeV^2 and g^2 = (-5.3 \\pm 9.0 + 2.7 -2.8) \\times 10^-17 GeV^2 for interaction ranges of 0.1 and 1.0 nm, respectively. These strengths correspond to 95% confidence level limits of g^2 < (1.4 \\pm 0.2) \\times 10^-14 GeV^-2 and g^2 < (1.3 \\pm 0.2) \\times 10^-16 GeV^-2, improving the current limits for interaction ranges between 4 and 0.04 nm by a factor of up to 10.

  12. Chemical factors influencing selenium atomization

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  13. Chemical factors influencing selenium atomization 

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  14. LABORATORY I FORCES AND EQUILIBRIUM

    E-Print Network [OSTI]

    Minnesota, University of

    of equilibrium is the result of a balance among all of the different forces interacting with the object (sections 1-10), chapter 4 (sections 1, 2, 5- 7), the paragraph at equation 6-13, chapter 10 (sections 5 problems before your lecturer addresses this material. So, it is very important that you read the text

  15. Heterogeneous Catalysis on Atomically Dispersed Supported Metals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction on Multifunctional Pd Catalysts. Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction...

  16. Selective Atomic Heating in Plasmas: Implications for Quantum Theory

    E-Print Network [OSTI]

    Phillips, Jonathan

    2008-01-01T23:59:59.000Z

    A new model of quantum mechanics, Classical Quantum Mechanics, is based on the (nearly heretical) postulate that electrons are physical objects that obey classical physical laws. Indeed, ionization energies, excitation energies etc. are computed based on picturing electrons as bubbles of charge that symmetrically surround a nucleus. Hence, for example, simple algebraic expressions based on Newtonian force balances are used to predict ionization energies and stable excitation states with remarkable precision. One of the most startling predictions of the model is that there are stable sizes of the hydrogen atom electron (bubble diameter) that are smaller (called hydrinos) than that calculated for the standard ground state. Experimental evidence in support of this novel physical/classical version of quantum is alleged to be found in the existence of super heated hydrogen atoms reported by many teams in a variety of plasmas. It is postulated that the energy required for creating super heated H aoms comes from the...

  17. Imaging atoms in 3-D

    ScienceCinema (OSTI)

    Ercius, Peter

    2014-06-27T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  18. Imaging atoms in 3-D

    SciTech Connect (OSTI)

    Ercius, Peter

    2013-10-31T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  19. Moøller polarimetry with polarized atomic hydrogen at MESA

    SciTech Connect (OSTI)

    Bartolomé, P. Aguar; Aulenbacher, K.; Tyukin, V. [Institut für Kernphysik, Johannes Gutenberg-University, D-55099 Mainz (Germany)

    2013-11-07T23:59:59.000Z

    A new generation of parity violation (PV) electron scattering experiments are planned to be carried out at the Institut für Kernphysik in Mainz. These experiments will be performed at low energies of 100-200 MeV using the new accelerator MESA (Mainz Energy recovering Superconducting Accelerator). One of the main challenges of such experiments is to achieve an accuracy in beam polarization measurements that must be below 0.5%. This very high accuracy can be reached using polarized atomic hydrogen gas, stored in an ultra-cold magnetic trap, as the target for electron beam polarimetry based on Mo/ller scattering. Electron spin-polarized atomic hydrogen can be stored at high densities of 10{sup 16} cm{sup ?2}, over relatively long time periods, in a high magnetic field (8T) and at low temperatures (0.3K). The gradient force splits the ground state of the hydrogen into four states with different energies. Atoms in the low energy states are trapped in the strong magnetic field region whereas the high energy states are repelled and pumped away. The physics of ultra-cold atomic hydrogen in magnetic traps and the status of the Mainz Hydro-Mo/ller project will be presented.

  20. Vibration atomic layer deposition for conformal nanoparticle coating

    SciTech Connect (OSTI)

    Park, Suk Won; Woo Kim, Jun; Jong Choi, Hyung; Hyung Shim, Joon, E-mail: shimm@korea.ac.kr [School of Mechanical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2014-01-15T23:59:59.000Z

    A vibration atomic layer deposition reactor was developed for fabricating a conformal thin-film coating on nanosize particles. In this study, atomic layer deposition of 10–15-nm-thick Al{sub 2}O{sub 3} films was conducted on a high-surface-area acetylene black powder with particle diameters of 200–250?nm. Intense vibration during the deposition resulted in the effective separation of particles, overcoming the interparticle agglomeration force and enabling effective diffusion of the precursor into the powder chunk; this phenomenon led to the formation of a conformal film coating on the nanopowder particles. It was also confirmed that the atomic layer deposition Al{sub 2}O{sub 3} films initially grew on the high-surface-area acetylene black powder particles as discrete islands, presumably because chemisorption of the precursor and water occurred only on a few sites on the high-surface-area acetylene black powder surface. Relatively sluggish growth of the films during the initial atomic layer deposition cycles was identified from composition analysis.

  1. Degradation of Staphylococcus aureus bacteria by neutral oxygen atoms

    SciTech Connect (OSTI)

    Cvelbar, U.; Mozetic, M. [Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Hauptman, N.; Klanjsek-Gunde, M. [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia)

    2009-11-15T23:59:59.000Z

    The degradation of Staphylococcus aureus bacteria during treatment with neutral oxygen atoms was monitored by scanning electron microscopy. Experiments were performed in an afterglow chamber made from borosilicate glass. The source of oxygen atoms was remote inductively coupled radiofrequency oxygen plasma. The density of atoms at the samples was 8x10{sup 20} m{sup -3}. The treatment was performed at room temperature. The first effect was the removal of dried capsule. Capsule on exposed parts of bacteria was removed after receiving the dose of 6x10{sup 23} at./m{sup 2}, while the parts of capsule filling the gaps between bacteria were removed after receiving the dose of 2.4x10{sup 24} m{sup -2}. After removing the capsule, degradation continued as etching of bacterial cell wall. The etching was rather nonuniform as holes with diameter of several 10 nm were observed. The cell wall was removed after receiving the dose of about 7x10{sup 24} m{sup -2}. The etching probabilities were about 2x10{sup -5} for the capsule and 2x10{sup -6} for the cell wall. The results were explained by different compositions of capsule and the cell wall.

  2. Recent Progress in ultracold atoms

    E-Print Network [OSTI]

    Baltisberger, Jay H.

    , cold gas experiments 2. How to make a BEC out of fermions 3. Recent Progress: Controlling Interaction (Feshbach Resonance) 4. From BCS to BEC: Rotating trap and spin- polarized condensates. 5. Future research and Einstein What is Bose-Einstein condensation (BEC)? #12;300 K to 1 mK 109 atoms 1 mK to 1 mK 108 106 atoms

  3. Absorption properties of identical atoms

    E-Print Network [OSTI]

    Pedro Sancho

    2013-07-31T23:59:59.000Z

    Emission rates and other optical properties of multiparticle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas.

  4. Optomechanical Rydberg-atom excitation via dynamic Casimir-Polder coupling

    E-Print Network [OSTI]

    Mauro Antezza; Caterina Braggio; Giovanni Carugno; Antonio Noto; Roberto Passante; Lucia Rizzuto; Giuseppe Ruoso; Salvatore Spagnolo

    2014-07-09T23:59:59.000Z

    We study the optomechanical coupling of a oscillating effective mirror with a Rydberg atomic gas, mediated by the dynamical atom-mirror Casimir-Polder force. This coupling may produce a near-field resonant atomic excitation whose probability scales as $\\propto (d^2\\;a\\;n^4\\;t)^2/z_0^8$, where $z_0$ is the average atom-surface distance, $d$ the atomic dipole moment, $a$ the mirror's effective oscillation amplitude, $n$ the initial principal quantum number, and $t$ the time. We propose an experimental configuration to realize this system with a cold atom gas trapped at a distance $\\sim 2\\cdot10 \\, \\mu$m from a semiconductor substrate, whose dielectric constant is periodically driven by an external laser pulse, hence realizing en effective mechanical mirror motion due to the periodic change of the substrate from transparent to reflecting. For a parabolic gas shape, this effect is predicted to excite about $\\sim 10^2$ atoms of a dilute gas of $10^3$ trapped Rydberg atoms with $n=75$ after about $0.5 \\,\\mu \\mbox{s}$, hence high enough to be detected in typical Rydberg gas experimental conditions.

  5. The Engineering of Optical Conservative Force

    E-Print Network [OSTI]

    Du, Junjie; Ding, Kun; Du, Guiqiang; Lin, Zhifang; Chan, C T; Ng, Jack

    2015-01-01T23:59:59.000Z

    Optical forces have been fruitfully applied in a broad variety of areas that not only span the traditional scientific fields such as physics, chemistry, and biology, but also in more applied fields. It is customary and useful to split the optical force into the (conservative) gradient force and the (non-conservative) scattering and absorption force. These forces are different in attributes. The ability to tailor them will open great potential in fundamental optics and practical applications. Here, we present an analytical and a numerical approach to calculate these forces, and, with these tools, we create a fairly general class of 2D conservative optical force field. In general, particles immersed in an optical force do not obey equilibrium statistical mechanics, making the analysis complicated. With conservative forces, these issues are resolved.

  6. Carmichael's Concise Review Microscopy is Only Skin Deep

    E-Print Network [OSTI]

    Heller, Eric

    Carmichael's Concise Review Microscopy is Only Skin Deep Stephen W. Carmichael Mayo Clinic. Coming Events 2011 EMAS 2011 May 15­19, 2011 Angers, France www.emas-web.net IUMAS-V May 22­27, 2011

  7. advanced microscopy techniques: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Syllabus MSE 581: Advanced Electron Microscopy Course description: Present the theory of...

  8. advanced electron microscopy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Syllabus MSE 581: Advanced Electron Microscopy Course description: Present the theory of...

  9. Scanning Tunneling Microscopy and Theoretical Study of Water...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Theoretical Study of Water Adsorption on Fe3O4: Implications for Catalysis. Scanning Tunneling Microscopy and Theoretical Study of Water Adsorption on Fe3O4: Implications...

  10. Optical fiber based ultrashort pulse multispectral nonlinear optical microscopy

    E-Print Network [OSTI]

    Larson, Adam Michael

    2009-05-15T23:59:59.000Z

    Nonlinear optical microscopy (NLOM) utilizing femtosecond laser pulses is well suited for imaging living tissues. This work reports on the design and development of an optical fiber based multispectral NLOM developed around a laser generating...

  11. Target-specific contrast agents for magnetic resonance microscopy

    E-Print Network [OSTI]

    Hepler Blackwell, Megan Leticia

    2007-01-01T23:59:59.000Z

    High-resolution ex vivo magnetic resonance microscopy (MRM) can be used to delineate prominent architectonic features in the human brain, but increased contrast is required to visualize more subtle distinctions. The goal ...

  12. Doppler optical coherence microscopy for studies of cochlear mechanics

    E-Print Network [OSTI]

    Hong, Stanley S.

    The possibility of measuring subnanometer motions with micron scale spatial resolution in the intact mammalian cochlea using Doppler optical coherence microscopy (DOCM) is demonstrated. A novel DOCM system is described ...

  13. X-Ray Diffraction Microscopy of Magnetic Structures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    12.0.2.2 Citation: J.J. Turner et al., "X-Ray Diffraction Microscopy of Magnetic Structures," Phys. Rev. Lett. 107, 033904 (2011). Web: http:prl.aps.orgpdfPRLv107i3e033904...

  14. Microwave probes Dipole Blockade and van der Waals Forces in a Cold Rydberg Gas

    E-Print Network [OSTI]

    R. Celistrino Teixeira; C. Hermann-Avigliano; Thanh Long Nguyen; T. Cantat-Moltrecht; Jean-Michel Raimond; S. Haroche; S. Gleyzes; M. Brune

    2015-02-14T23:59:59.000Z

    We show that microwave spectroscopy of a dense Rydberg gas trapped on a superconducting atom chip in the dipole blockade regime reveals directly the dipole-dipole many-body interaction energy spectrum. We use this method to investigate the expansion of the Rydberg cloud under the effect of repulsive van der Waals forces and the breakdown of the frozen gas approximation. This study opens a promising route for quantum simulation of many-body systems and quantum information transport in chains of strongly interacting Rydberg atoms.

  15. Microwave probes Dipole Blockade and van der Waals Forces in a Cold Rydberg Gas

    E-Print Network [OSTI]

    Teixeira, R Celistrino; Nguyen, Thanh Long; Cantat-Moltrecht, T; Raimond, Jean-Michel; Haroche, S; Gleyzes, S; Brune, M

    2015-01-01T23:59:59.000Z

    We show that microwave spectroscopy of a dense Rydberg gas trapped on a superconducting atom chip in the dipole blockade regime reveals directly the dipole-dipole many-body interaction energy spectrum. We use this method to investigate the expansion of the Rydberg cloud under the effect of repulsive van der Waals forces and the breakdown of the frozen gas approximation. This study opens a promising route for quantum simulation of many-body systems and quantum information transport in chains of strongly interacting Rydberg atoms.

  16. Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis

    E-Print Network [OSTI]

    Kang, Jeon Woong

    We have developed a novel multimodal microscopy system that incorporates confocal Raman, confocal reflectance, and quantitative phase microscopy (QPM) into a single imaging entity. Confocal Raman microscopy provides detailed ...

  17. Centrifugal force in Kerr geometry

    E-Print Network [OSTI]

    Sai Iyer; A R Prasanna

    1992-07-31T23:59:59.000Z

    We have obtained the correct expression for the centrifugal force acting on a particle at the equatorial circumference of a rotating body in the locally non-rotating frame of the Kerr geometry. Using this expression for the equilibrium of an element on the surface of a slowly rotating Maclaurin spheroid, we obtain the expression for the ellipticity (as discussed earlier by Abramowicz and Miller) and determine the radius at which the ellipticity is maximum.

  18. Hydrodynamic forces on piggyback pipelines

    SciTech Connect (OSTI)

    Jakobsen, M.L.; Sayer, P. [Univ. of Strathclyde, Glasgow (United Kingdom)

    1995-12-31T23:59:59.000Z

    An increasing number of new offshore pipelines have been designed as bundles, mainly because of overall cost reductions. One popular way of combining two pipelines with different diameters is the piggyback configuration, with the smaller pipeline strapped on top of the main pipeline. The external hydrodynamic forces on this combination are at present very roughly estimated; pipeline engineers need more data to support their designs. This paper presents experimental results for the in-line hydrodynamic loading on three different piggyback set-ups. The models comprised a 0.4 m main pipeline, and three piggyback pipelines with diameters of 0.038 m, 0.059 m and 0.099 m. Each small pipeline was separately mounted to the main pipeline, with a gap equal to its own diameter. These model sizes lie approximately between half- and full-scale. Experiments were undertaken for K{sub C} between 5 and 42, and R{sub e} in the range 0.0 * 10{sup 4} to 8.5 * 10{sup 5}. The results based on Morison`s equation indicate that a simple addition of the separate forces acting on each cylinder underestimates the actual force by up to 35% at low K{sub C} (< {approximately} 10) and by as much as 100% in the drag-dominated regime (K{sub C} > {approximately} 20).

  19. Friction forces in cosmological models

    E-Print Network [OSTI]

    Donato Bini; Andrea Geralico; Daniele Gregoris; Sauro Succi

    2014-08-23T23:59:59.000Z

    We investigate the dynamics of test particles undergoing friction forces in a Friedmann-Robertson-Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting-Robertson-like friction force in the equations of motion, leading to measurable (at least in principle) deviations of the particle trajectories from geodesic motion. The effect on the peculiar velocities of the particles is investigated for various equations of state of the background fluid and different standard cosmological models. The friction force is found to have major effects on particle motion in closed FRW universes, where it turns the time-asymptotic value (approaching the recollapse) of the peculiar particle velocity from ultra-relativistic (close to light speed) to a co-moving one, i.e., zero peculiar speed. On the other hand, for open or flat universes the effect of the friction is not so significant, because the time-asymptotic peculiar particle speed is largely non-relativistic also in the geodesic case.

  20. Investigation of Micro- and Macro-Scale Transport Processes for...

    Broader source: Energy.gov (indexed) [DOE]

    cell performance models? Techniques employed: KL More, DOE Report 2005. * Small-angle neutron scattering, atomic force microscopy (ionic morphology) * Neutron on reflectometry...

  1. Microsoft Word - Equipment-Training List

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scanning and Probing Microscopy Environmental Closed Loop Atomic Force Microscope - Asylum MFD-3D-BIO CFN Safety Module for Users - NC-ESH-USERS Cyber Security Training -...

  2. Revealing the atomic and electronic structure of a SrTiO{sub 3}/LaNiO{sub 3}/SrTiO{sub 3} heterostructure interface

    SciTech Connect (OSTI)

    Zhang, Zaoli, E-mail: zaoli.zhang@oeaw.ac.at [Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben (Austria); Electron Microscopy Group for Materials Science, University of Ulm, Ulm (Germany); Soltan, S. [Max-Planck Institute for Solid State Research, D-70561 Stuttgart (Germany); Faculty of Science, Helwan University, 11795 Cairo (Egypt); Schmid, H. [INM—Leibniz-Institut für Neue Materialien, 66123 Saarbrücken (Germany); Habermeier, H.-U.; Keimer, B. [Max-Planck Institute for Solid State Research, D-70561 Stuttgart (Germany); Kaiser, U. [Electron Microscopy Group for Materials Science, University of Ulm, Ulm (Germany)

    2014-03-14T23:59:59.000Z

    The atomic structures of SrTiO{sub 3} (STO)/LaNiO{sub 3} (LNO)/STO heterostructure interfaces were investigated by spherical aberration-corrected (C{sub S}) (scanning) transmission electron microscopy. Atomic displacement and lattice distortion measurements and electron energy loss spectroscopy (EELS) were used to quantitatively analyze the distortion of the interfacial octahedra and the bond length at the interfaces. Combined with high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy analyses, two distinct interfacial atomic terminating layers are unambiguously determined. Ensuing quantitative HRTEM measurements revealed that the Ni-O bond length in the interfacial octahedral is elongated at the bottom interface (–NiO{sub 2}-SrO–). Atomic displacement shows structural relaxation effects when crossing the interfaces and lattice distortions across the interface is more pronounced in LNO than in STO. The Ti/O atomic ratio, La and Ti relative atomic ratio as derived by EELS quantification indicate non-stoichiometric composition at the interfaces. Distinct fine structures of Ti-L{sub 2,3} edge and O-K edge at the bottom and top interfaces are observed. By comparison, we are able to estimate Ti valency at both interfaces. Combining the structural distortions and Ti valency, the polar discontinuity and charge transfer at the interfaces are discussed.

  3. Accelerometer using atomic waves for space applications

    E-Print Network [OSTI]

    of Bose-Einstein condensation (BEC) of a dilute gas of trapped atoms in a single quantum state [18, 19, 20 of such devices in the field of navigation, surveying and analysis of earth structures. Matter-wave interferometry that the use of Bose-Einstein condensed atoms will bring the science of atom optics, and in particular atom

  4. Magnetic force microscopy and x-ray scattering study of 70550 nm2 pseudo-spin-valve nanomagnets

    E-Print Network [OSTI]

    Grütter, Peter

    The magnetic properties of lithographically defined mul- tilayered magnetic solids with three dimensions reversal is affected by the shape and reduced dimensions of these nanomagnets are of considerable interest or metallic spacer. Future high-density MRAM devices will require layered magnetic elements with thicknesses

  5. Josephson scanning tunneling microscopy -- a local and direct probe of the superconducting order parameter

    E-Print Network [OSTI]

    Kimura, Hikari

    2010-01-01T23:59:59.000Z

    Title Josephson scanning tunneling microscopy – a local andthe sample using a novel scanning tunneling microscope (STM)discussed. I. INTRODUCTION Scanning tunneling microscopy (

  6. Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental Science Beamline at the Advanced Light Source. Soft X-Ray Microscopy and Spectroscopy at the Molecular...

  7. Swept source optical coherence microscopy for pathological assessment of cancerous tissues

    E-Print Network [OSTI]

    Ahsen, Osman Oguz

    2013-01-01T23:59:59.000Z

    Optical coherence microscopy (OCM) combines optical coherence tomography (OCT) with confocal microscopy and enables depth resolved visualization of biological specimens with cellular resolution. OCM offers a suitable ...

  8. On Dynamic Models of Robot Force Control

    E-Print Network [OSTI]

    Eppinger, Steven D.

    1986-07-01T23:59:59.000Z

    For precise robot control, endpoint compliance strategies utilize feedback from a force sensor located near the tool/workpiece interface. Such endpoint force control systems have been observed in the laboratory to be ...

  9. Handheld force-controlled ultrasound probe

    E-Print Network [OSTI]

    Gilbertson, Matthew Wright

    2010-01-01T23:59:59.000Z

    An hand-held force controlled ultrasound probe has been developed. The controller maintains a prescribed contact force between the probe and a patient's body. The device will enhance the diagnostic capability of free-hand ...

  10. Atomic Cascade in Muonic and Hadronic Hydrogen Atoms

    E-Print Network [OSTI]

    T. S. Jensen; V. P. Popov; V. N. Pomerantsev

    2007-12-18T23:59:59.000Z

    The atomic cascade in $\\mu^- p$ and $\\pi^- p$ atoms has been studied with the improved version of the extended cascade model in which new quantum mechanical calculations of the differential and integral cross sections of the elastic scattering, Stark transitions and Coulomb de-excitation have been included for the principal quantum number values $n\\le 8$ and the relative energies $E \\ge 0.01$ eV. The $X$-ray yields and kinetic energy distributions are compared with the experimental data.

  11. Quantum Electrodynamics of Atomic Resonances

    E-Print Network [OSTI]

    Miguel Ballesteros; Jérémy Faupin; Jürg Fröhlich; Baptiste Schubnel

    2015-03-09T23:59:59.000Z

    A simple model of an atom interacting with the quantized electromagnetic field is studied. The atom has a finite mass $m$, finitely many excited states and an electric dipole moment, $\\vec{d}_0 = -\\lambda_{0} \\vec{d}$, where $\\| d^{i}\\| = 1,$ $ i=1,2,3,$ and $\\lambda_0$ is proportional to the elementary electric charge. The interaction of the atom with the radiation field is described with the help of the Ritz Hamiltonian, $-\\vec{d}_0\\cdot \\vec{E}$, where $\\vec{E}$ is the electric field, cut off at large frequencies. A mathematical study of the Lamb shift, the decay channels and the life times of the excited states of the atom is presented. It is rigorously proven that these quantities are analytic functions of the momentum $\\vec{p}$ of the atom and of the coupling constant $\\lambda_0$, provided $|\\vec{p}| < mc$ and $| \\Im\\vec{p} |$ and $| \\lambda_{0} |$ are sufficiently small. The proof relies on a somewhat novel inductive construction involving a sequence of `smooth Feshbach-Schur maps' applied to a complex dilatation of the original Hamiltonian, which yields an algorithm for the calculation of resonance energies that converges super-exponentially fast.

  12. Transmission electron microscopy investigation of acicular ferrite precipitation in {gamma}'-Fe{sub 4}N nitride

    SciTech Connect (OSTI)

    Xiong, X.C., E-mail: xiaochuan.xiong@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Institut Jean Lamour, UMR 7198 CNRS, Nancy-Universite, UPV-Metz, Ecole des Mines de Nancy, Parc de Saurupt CS 14234, F-54042 Nancy Cedex (France); Redjaimia, A. [Institut Jean Lamour, UMR 7198 CNRS, Nancy-Universite, UPV-Metz, Ecole des Mines de Nancy, Parc de Saurupt CS 14234, F-54042 Nancy Cedex (France); Goune, M. [Institut Jean Lamour, UMR 7198 CNRS, Nancy-Universite, UPV-Metz, Ecole des Mines de Nancy, Parc de Saurupt CS 14234, F-54042 Nancy Cedex (France); ArcelorMittal SA, Voie Romaine, BP 30320, F-57283 Maizieres-les-Metz (France)

    2010-11-15T23:59:59.000Z

    Acicular-shaped crystals precipitate from {gamma}'-Fe{sub 4}N nitride in an iron-nitrogen alloy and were identified by electron microdiffraction as {alpha}-ferrite. Acicular ferrite develops both the Nishiyama-Wassermann and the Kurdjumov-Sachs orientation relationships with {gamma}'-Fe{sub 4}N nitride. These orientation relationships were discussed in terms of the symmetry theory. The driving force for acicular ferrite formation was related to the increasing nitrogen content of {gamma}'-Fe{sub 4}N, in equilibrium with {alpha}-ferrite, with decreasing temperature. The passage from lamellar to acicular structure in Fe-N system was proposed. - Research Highlights: {yields} Acicular crystals precipitate from pearlitic{gamma}'-Fe{sub 4}N nitride in an iron-nitrogen alloy and were identified by electron microdiffraction as acicular ferrite. {yields} The crystal structure, orientation relationships with the matrix and morphologies of acicular ferrite, were studied by transmission electron microscopy. {yields} The driving force for the formation of acicular ferrite is related to the temperature dependence of nitrogen content of {gamma}'-Fe{sub 4}N, in equilibrium with ferrite. {yields} The passage from the pearlitic structure to the acicular structure in the present iron-nitrogen alloy was proposed.

  13. Local characterization of hindered Brownian motion by using digital video microscopy and 3D particle tracking

    E-Print Network [OSTI]

    Simon L Dettmer; Ulrich F Keyser; Stefano Pagliara

    2014-08-19T23:59:59.000Z

    In this article we present methods for measuring hindered Brownian motion in the confinement of complex 3D geometries using digital video microscopy. Here we discuss essential features of automated 3D particle tracking as well as diffusion data analysis. By introducing local mean squared displacement-vs-time curves, we are able to simultaneously measure the spatial dependence of diffusion coefficients, tracking accuracies and drift velocities. Such local measurements allow a more detailed and appropriate description of strongly heterogeneous systems as opposed to global measurements. Finite size effects of the tracking region on measuring mean squared displacements are also discussed. The use of these methods was crucial for the measurement of the diffusive behavior of spherical polystyrene particles (505 nm diameter) in a microfluidic chip. The particles explored an array of parallel channels with different cross sections as well as the bulk reservoirs. For this experiment we present the measurement of local tracking accuracies in all three axial directions as well as the diffusivity parallel to the channel axis while we observed no significant flow but purely Brownian motion. Finally, the presented algorithm is suitable also for tracking of fluorescently labeled particles and particles driven by an external force, e.g. electrokinetic or dielectrophoretic forces.

  14. Nuclear Radiological Threat Task Force Established | National...

    National Nuclear Security Administration (NNSA)

    Radiological Threat Task Force Established | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

  15. Degeneracy Breaking of Hydrogen Atom

    E-Print Network [OSTI]

    Agung Trisetyarso; Pantur Silaban

    2014-11-21T23:59:59.000Z

    The three dimensional rotation group, SO(3), is a symmetry group of the normal hydrogen atom. Each reducible representation of this group can be associated with a degenerate energy level. If this atom is placed in an external magnetic field, the interaction between the orbital magnetic moment with this field will lead to a symmetry breaking where the symmetry group of the atom is a new group distinct from the SO(3) group. This phenomenon describes the normal Zeeman effect, where a degenerate energy level splits into several new energy levels. It is explicitly shown that each of the new energy levels can be associated with an irreducible representation of the new symmetry group.

  16. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

    1997-01-01T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid.

  17. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1997-07-08T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid. 3 figs.

  18. Nanoplasmonic Lattices for Ultracold atoms

    E-Print Network [OSTI]

    M. Gullans; T. Tiecke; D. E. Chang; J. Feist; J. D. Thompson; J. I. Cirac; P. Zoller; M. D. Lukin

    2014-07-25T23:59:59.000Z

    We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.

  19. Glacial cycles and astronomical forcing

    SciTech Connect (OSTI)

    Muller, R.A. [Lawrence Berkeley Lab., CA (United States)] [Lawrence Berkeley Lab., CA (United States); MacDonald, G.J. [International Institute for Applied Systems Analysis, Laxenburg (Austria)] [International Institute for Applied Systems Analysis, Laxenburg (Austria)

    1997-07-11T23:59:59.000Z

    Narrow spectral features in ocean sediment records offer strong evidence that the cycles of glaciation were driven by astronomical forces. Two million years ago, the cycles match the 41,000-year period of Earth`s obliquity. This supports the Croll/Milankovitch theory, which attributes the cycles to variations in insolation. But for the past million years, the spectrum is dominated by a single 100,000-year feature and is a poor match to the predictions of insolation models. The spectrum can be accounted for by a theory that derives the cycles of glaciation from variations in the inclination of Earth`s orbital plane.

  20. Thermomagnetic Force in Polyatomic Gases

    E-Print Network [OSTI]

    Larchez, M. E.; Adair, Thomas W.

    1971-01-01T23:59:59.000Z

    decreases as H/P is increased above about 500 Oe/Torr. Another difference in the two effects is that the SB effect is a universal function of H/P for the entire range of values covered. This does not appear to be true in the force effect. For NO... magnetic field also causes a de- crease in the shear viscosity of oxygen. These effects in Oz were later observed in NO and were extensively studied. It was observed that the trans- port coefficients decrease in a magnetic field 8, that the effect...

  1. E-Print Network 3.0 - all-atom force field Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    coordinates and velocities for all... , simulation of long-time processes(like protein folding, new phase ... Source: Southern California, University of - Collaboratory for...

  2. Near-Grazing Dynamics in Tapping-Mode Atomic Force Harry Dankowicza

    E-Print Network [OSTI]

    Zhao, Xiaopeng

    bifurcations, discontinuity mappings. 1 Introduction Nanostructured materials and devices can be endowed as hydrogen storage devices. Similarly, self-assembly of ferromag- netic nanoparticles is a promising technique for producing high-density magnetic data storage devices and biomedical materials with desirable

  3. A Preisach Model for Quantifying Hysteresis in an Atomic Force Microscope

    E-Print Network [OSTI]

    . increases to the point where feedback mechanisms are amplifying noise rather than attenuating unmodeled and constitutive nonlin- earities even at low drive levels. Feedback mechanisms can mitigate the deleterious effects of these nonlinearities for low frequency operation but such techniques fail at higher frequencies

  4. A Preisach Model for Quantifying Hysteresis in an Atomic Force Microscope

    E-Print Network [OSTI]

    #ects of these nonlinearities for low frequency operation but such techniques fail at higher frequencies due to increased noise lateral sweep. increases to the point where feedback mechanisms are amplifying noise rather than and constitutive nonlin­ earities even at low drive levels. Feedback mechanisms can mitigate the deleterious e

  5. Viscoelastic Study Using an Atomic Force Microscope Modified to Operate as a Nanorheometer

    E-Print Network [OSTI]

    Attard, Phil

    pharmaceutical compounds, through to polymer composites,blends,novelorganicsemiconductornetworks, and even,11,12 Although category I nanorheology can be conducted without any subsequent modification to the existing AFM

  6. Atomic-Scale Simulation of Colloidal Nanoparticle Forces and Kristen A. Fichthorn

    E-Print Network [OSTI]

    Bjørnstad, Ottar Nordal

    areas in dye-sensitized solar cells, where their aggregation and interfacial structure can influence cells. Nanoparticles also figure prominently in solar-cell technologies, for example as efficient light

  7. Modeling forces in high-temperature superconductors

    SciTech Connect (OSTI)

    Turner, L. R.; Foster, M. W.

    1997-11-18T23:59:59.000Z

    We have developed a simple model that uses computed shielding currents to determine the forces acting on a high-temperature superconductor (HTS). The model has been applied to measurements of the force between HTS and permanent magnets (PM). Results show the expected hysteretic variation of force as the HTS moves first toward and then away from a permanent magnet, including the reversal of the sign of the force. Optimization of the shielding currents is carried out through a simulated annealing algorithm in a C++ program that repeatedly calls a commercial electromagnetic software code. Agreement with measured forces is encouraging.

  8. Air Force Research Laboratory Placement: Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson

    E-Print Network [OSTI]

    Alpay, S. Pamir

    Air Force Research Laboratory Placement: Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton OH Discipline(s): Materials science/engineering, chemical. Description: We are looking for a qualified candidate to join our team at the Air Force Research Laboratory

  9. Wood Fuel Task Force Response 2 | Wood Fuel Task Force Response

    E-Print Network [OSTI]

    Wood Fuel Task Force Response #12;2 | Wood Fuel Task Force Response #12;Wood Fuel Task Force Response | 3 Wood Fuel Task Force Response Scottish Government response by Minister for Environment, Michael Russell I am pleased to present on behalf of the Scottish Government our response to the Wood Fuel

  10. Exact theory and numeric results for short pulse ionization of simple model atom in one dimension

    E-Print Network [OSTI]

    Rokhlenko, Alexander

    2015-01-01T23:59:59.000Z

    Our exact theory for continuous harmonic perturbation of a one dimensional model atom by parametric variations of its potential is generalized for the cases when a) the atom is exposed to short pulses of an external harmonic electric field and b) the forcing is represented by short bursts of different shape changing the strength of the binding potential. This work is motivated not only by the wide use of laser pulses for atomic ionization, but also by our earlier study of the same model which successfully described the ionization dynamics in all orders, i.e. the multi-photon processes, though being treated by the non-relativistic Schr\\"odinger equation. In particular, it was shown that the bound atom cannot survive the excitation of its potential caused by any non-zero frequency and amplitude of the continuous harmonic forcing. Our present analysis found important laws of the atomic ionization by short pulses, in particular the efficiency of ionizing this model system and presumably real ones as well.

  11. An ultra-bright atom laser

    E-Print Network [OSTI]

    V. Bolpasi; N. K. Efremidis; M. J. Morrissey; P. Condylis; D. Sahagun; M. Baker; W. von Klitzing

    2013-11-25T23:59:59.000Z

    We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).

  12. Ab-initio friction forces on the nanoscale: A DFT study of fcc Cu(111)

    E-Print Network [OSTI]

    Michael Wolloch; Gregor Feldbauer; Peter Mohn; Josef Redinger; András Vernes

    2014-08-26T23:59:59.000Z

    While there are a number of models that tackle the problem of calculating friction forces on the atomic level, providing a completely parameter-free approach remains a challenge. Here we present a quasi-static model to obtain an approximation to the nanofrictional response of dry, wearless systems based on quantum mechanical all-electron calculations. We propose a mechanism to allow dissipative sliding, which relies on atomic relaxations. We define two different ways of calculating the mean nanofriction force, both leading to an exponential friction-versus-load behavior for all sliding directions. Since our approach does not impose any limits on lengths and directions of the sliding paths, we investigate arbitrary sliding directions for an fcc Cu(111) interface and detect two periodic paths which form the upper and lower bound of nanofriction. For long aperiodic paths the friction force convergences to a value in between these limits. For low loads we retrieve the Derjaguin generalization of Amontons-Coulomb kinetic friction law which appears to be valid all the way down to the nanoscale. We observe a non-vanishing Derjaguin-offset even for atomically flat surfaces in dry contact.

  13. Microstructure Evolution of Gas Atomized Iron Based ODS Alloys

    SciTech Connect (OSTI)

    Rieken, J.R.; Anderson, I.E.; Kramer, M.J.

    2011-08-09T23:59:59.000Z

    In a simplified process to produce precursor powders for oxide dispersion-strengthened (ODS) alloys, gas-atomization reaction synthesis (GARS) was used to induce a surface oxide layer on molten droplets of three differing erritic stainless steel alloys during break-up and rapid solidification. The chemistry of the surface oxide was identified using auger electron spectroscopy (AES) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The precursor iron-base powders were consolidated at 850 C and 1,300 C using hot isostatic pressing (HIPing). Consolidation at the lower temperature resulted in a fully dense microstructure, while preventing substantial prior particle-boundary-oxide dissociation. Microstructural analysis of the alloys consolidated at the higher temperature confirmed a significant reduction in prior-particle-boundary-oxide volume fraction, in comparison with the lower-temperature-consolidated sample. This provided evidence that a high-temperature internal oxygen-exchange reaction occurred between the metastable prior particle-boundary-oxide phase (chromium oxide) and the yttrium contained within each prior particle. This internal oxygen-exchange reaction is shown to result in the formation of yttrium-enriched oxide dispersoids throughout the alloy microstructure. The evolving microstructure was characterized using transmission electron microscopy (TEM) and high-energy X-ray diffraction (HE-XRD).

  14. Direct measurement of thermophoretic forces

    E-Print Network [OSTI]

    Laurent Helden; Ralf Eichhorn; Clemens Bechinger

    2014-12-19T23:59:59.000Z

    We study the thermophoretic motion of a micron sized single colloidal particle in front of a flat wall by evanescent light scattering. To quantify thermophoretic effects we analyse the nonequilibrium steady state (NESS) of the particle in a constant temperature gradient perpendicular to the confining walls. We propose to determine thermophoretic forces from a 'generalized potential' associated with the probability distribution of the particle position in the NESS. Experimentally we demonstrate, how this spatial probability distribution is measured and how thermophoretic forces can be extracted with 10 fN resolution. By varying temperature gradient and ambient temperature, the temperature dependence of Soret coefficient $S_T(T)$ is determined for $r = 2.5 \\mu m$ polystyrene and $r = 1.35 \\mu m$ melamine particles. The functional form of $S_T(T)$ is in good agreement with findings for smaller colloids. In addition, we measure and discuss hydrodynamic effects in the confined geometry. The theoretical and experimental technique proposed here extends thermophoresis measurements to so far inaccessible particle sizes and particle solvent combinations.

  15. Air Force Renewable Energy Programs | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Air Force Renewable Energy Programs Air Force Renewable Energy Programs Presentation covers Air Force Renewable Energy Programs and is given at the Spring 2011 Federal Utility...

  16. Protective Force Protocols for ESS Supported Performance Tests...

    Broader source: Energy.gov (indexed) [DOE]

    security force-on-force performance tests and exercises. Protective Force Protocols for ESS Supported Performance Tests and Exercises, March 12, 2007 More Documents & Publications...

  17. ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS

    E-Print Network [OSTI]

    Johnson, Robert E.

    ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS TO CONTINUUM MECHANICS Ejection of simple and complex molecules from surfaces probes the response of condensed matter to electronic excitations and has and Engineering Physics at the University of Virginia, Charlottesville. Bo Sundqvist holds the Chair in Ion

  18. Photoabsorption by Ions and Atoms

    SciTech Connect (OSTI)

    Manson, Steven T. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)

    2004-12-01T23:59:59.000Z

    Recent progress in theoretical and experimental investigations of photoabsorption by atoms and ions is presented. Specifically, examples of near-chaotic behavior in photoionization of positive ions, low-energy manifestations of nondipole effects, high-energy breakdown of the single particle picture and new phenomenology uncovered in the inner-shell photoabsorption by negative ions are discussed.

  19. Imaging hydrated microbial extracellular polymers: Comparative analysis by electron microscopy

    SciTech Connect (OSTI)

    Dohnalkova, A.C.; Marshall, M. J.; Arey, B. W.; Williams, K. H.; Buck, E. C.; Fredrickson, J. K.

    2011-01-01T23:59:59.000Z

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryogenic electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of the hydrated bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in their collapse into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.

  20. Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy

    SciTech Connect (OSTI)

    Dohnalkova, Alice; Marshall, Matthew J.; Arey, Bruce W.; Williams, Kenneth H.; Buck, Edgar C.; Fredrickson, Jim K.

    2011-02-01T23:59:59.000Z

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryo-electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in the collapse of hydrated gel-like EPS into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.