National Library of Energy BETA

Sample records for ncem electron microscopy

  1. 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...

  2. Dynamic Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Evans, James E.; Jungjohann, K. L.; Browning, Nigel D.

    2012-10-12

    Dynamic transmission electron microscopy (DTEM) combines the benefits of high spatial resolution electron microscopy with the high temporal resolution of ultrafast lasers. The incorporation of these two components into a single instrument provides a perfect platform for in situ observations of material processes. However, previous DTEM applications have focused on observing structural changes occurring in samples exposed to high vacuum. Therefore, in order to expand the pump-probe experimental regime to more natural environmental conditions, in situ gas and liquid chambers must be coupled with Dynamic TEM. This chapter describes the current and future applications of in situ liquid DTEM to permit time-resolved atomic scale observations in an aqueous environment, Although this chapter focuses mostly on in situ liquid imaging, the same research potential exists for in situ gas experiments and the successful integration of these techniques promises new insights for understanding nanoparticle, catalyst and biological protein dynamics with unprecedented spatiotemporal resolution.

  3. The Future of Electron Microscopy

    SciTech Connect (OSTI)

    Zheng, Haimei

    2015-05-06

    Berkeley Lab scientist Haimei Zheng discusses the future of electron microscopy and her breakthrough research into examining liquids using an electron microscope.

  4. News Item

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

    Molecular Foundry and NCEM Merge Complete As of October 1, 2014, the Molecular Foundry includes the National Center for Electron Microscopy (NCEM). Previously, NCEM was a separate...

  5. Electron Microscopy Catalysis Projects: Success Stories from...

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

    Electron Microscopy Catalysis Projects: Success Stories from the High Temperature Materials Laboratory (HTML) User Program Electron Microscopy Catalysis Projects: Success Stories ...

  6. Dynamic imaging with electron microscopy

    ScienceCinema (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-05-30

    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.

  7. NREL: Measurements and Characterization - Scanning Electron Microscopy

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

    Electron Microscopy Researcher using field-emission scanning electron microscope. Field emission scanning electron microscope (FE-SEM) JEOL 6320F. This FE-SEM equipped with a cold field-emission source and in-lens detectors is designed for ultra-high resolution at low accelerating voltage. Compositional mapping by energy-dispersive microscopy and Electron Backscattered Diffraction are available. In basic scanning electron microscopy (SEM), a beam of highly energetic (0.1-50 keV) electrons is

  8. Combining Quantitative Electrochemistry and Electron Microscopy...

    Office of Scientific and Technical Information (OSTI)

    Conference: Combining Quantitative Electrochemistry and Electron Microscopy to Study ... Resource Relation: Conference: Proposed for presentation at the Materials Research Society ...

  9. Scientific Achievement Analytical Transmission Electron Microscopy

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

    Analytical Transmission Electron Microscopy (TEM) method was developed to determine thickness and wrinkles in electron beam sensitive 2-dimensional (2D) MFI nanosheets....

  10. Electron Microscopy Center | Argonne National Laboratory

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

    Electron Microscopy Center Electron Microscopy Center The Electron Microscopy Center Group (EMC) develops and maintains unique capabilities for electron beam characterization and applies those capabilities to solve materials challenges. EMC emphasizes three major areas: materials research, experimental technique and instrumentation development, and operation of unique and state-of-the-art instrumentation. The goals of EMC materials research are closely aligned with those of our user community.

  11. In Situ Transmission Electron Microscopy

    Office of Scientific and Technical Information (OSTI)

    ... Nanofactory Atomic Force Microscopy (AFM) Stage * Measures force interactions on samples with higher sensitivity than the NanoIndentation stage * Load range between 10 - 2,000 nN * ...

  12. Fast electron microscopy via compressive sensing

    DOE Patents [OSTI]

    Larson, Kurt W; Anderson, Hyrum S; Wheeler, Jason W

    2014-12-09

    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.

  13. The future of electron microscopy

    SciTech Connect (OSTI)

    Zhu, Yimei; Durr, Hermann

    2015-04-01

    Seeing is believing. So goes the old adage and seen evidence is undoubtedly satisfying because it can be interpreted easily, though not always correctly. For centuries, humans have developed such instruments as telescopes that observe the heavens and microscopes that reveal bacteria and viruses. The 2014 Nobel Prize in Chemistry was awarded to Eric Betzig, Stefan Hell, and William Moerner for their foundational work on superresolution fluorescence microscopy in which they overcame the Abbe diffraction limit for the resolving power of conventional light microscopes. (See Physics Today, December 2014, page 18.) That breakthrough enabled discoveries in biological research and testifies to the importance of modern microscopy.

  14. The future of electron microscopy

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

    Zhu, Yimei; Durr, Hermann

    2015-04-01

    Seeing is believing. So goes the old adage and seen evidence is undoubtedly satisfying because it can be interpreted easily, though not always correctly. For centuries, humans have developed such instruments as telescopes that observe the heavens and microscopes that reveal bacteria and viruses. The 2014 Nobel Prize in Chemistry was awarded to Eric Betzig, Stefan Hell, and William Moerner for their foundational work on superresolution fluorescence microscopy in which they overcame the Abbe diffraction limit for the resolving power of conventional light microscopes. (See Physics Today, December 2014, page 18.) That breakthrough enabled discoveries in biological research and testifiesmore » to the importance of modern microscopy.« less

  15. 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 2011 DOE Hydrogen and Fuel Cells Program, ...

  16. 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 ...

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

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

    More Documents & Publications In-Situ Electron Microscopy of Electrical Energy Storage Materials In-Situ Electron Microscopy of Electrical Energy Storage Materials Investigations ...

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

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

    More Documents & Publications In-Situ Electron Microscopy of Electrical Energy Storage Materials In-Situ Electron Microscopy of Electrical Energy Storage Materials In-situ ...

  19. In Situ Transmission Electron Microscopy. (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    In Situ Transmission Electron Microscopy. Citation Details In-Document Search Title: In Situ Transmission Electron Microscopy. Abstract not provided. Authors: Jungjohann, Katherine ...

  20. Subangstrom Edge Relaxations Probed by Electron Microscopy in...

    Office of Scientific and Technical Information (OSTI)

    Subangstrom Edge Relaxations Probed by Electron Microscopy in Hexagonal Boron Nitride Title: Subangstrom Edge Relaxations Probed by Electron Microscopy in Hexagonal Boron Nitride ...

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

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

    pm029allard2010p.pdf More Documents & Publications Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst...

  2. Frontiers of in situ electron microscopy

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

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

    2015-01-01

    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

  3. Electron Microscopy Center Capabilities | Argonne National Laboratory

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

    Electron Microscopy Center Capabilities ACAT: Argonne Chromatic Aberration-corrected TEM This FEI Titan 80-300 ST has a CEOS Cc/Cs corrector on the imaging side of the column to correct both spherical and chromatic aberrations. The Cc/Cs corrector also provides greatly-improved resolution and signal for energy filtered imaging and EELS. FEI Tecnai F20ST TEM/STEM This premier analytical transmission electron microscope (AEM) has specialized accessories including an energy-dispersive x-ray

  4. Electron Microscopy > Analytical Resources > Research > The Energy

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

    Materials Center at Cornell Analytical Resources In This Section Differential Electrochemical Mass Spectroscopy (DEMS) Electron Microscopy X-Ray Diffraction Electron Microscopy Aberration-Corrected Electron Microscope Facility Electron microscopy provides atomic-resolution images of the structure, composition and bonding of our fuel cells and their components. Three-dimensional images of catalyst particles and their support materials are constructed using electron tomography - a similar

  5. News Item

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

    NCEM Leadership Change After more than 20 years as Director of the National Center for Electron Microscopy (NCEM), Ulrich Dahmen has stepped into a new role as NCEM Senior Advisor, effective March 15. As Senior Advisor, Dahmen will be focusing on multidisciplinary materials research and helping to set the agenda for electron microscopy research at the Molecular Foundry and NCEM, which are merging into a single User Facility later this year. Under Dahmen's leadership, NCEM has become DOE's

  6. In situ transmission electron microscopy investigation of the...

    Office of Scientific and Technical Information (OSTI)

    In situ transmission electron microscopy investigation of the interfacial reaction between Ni and Al during rapid heating in a nanocalorimeter Grapes, Michael D. Department of...

  7. In situ transmission electron microscopy investigation of the...

    Office of Scientific and Technical Information (OSTI)

    Published Article: In situ transmission electron microscopy investigation of the interfacial reaction between Ni and Al during rapid heating in a nanocalorimeter Title: In situ...

  8. A Sealed Liquid Cell for In Situ Transmission Electron Microscopy...

    Office of Scientific and Technical Information (OSTI)

    A Sealed Liquid Cell for In Situ Transmission Electron Microscopy of Controlled Electrochemical Processes Citation Details In-Document Search Title: A Sealed Liquid Cell for In ...

  9. Scanning Transmission Electron Microscopy Investigations of Complex Oxides

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

    | Stanford Synchrotron Radiation Lightsource 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 Chemistry, University of South Carolina High-Angle-Annular-Dark-Field/Scanning Transmission Electron Microscopy (HAADF/STEM) is a technique uniquely suited for detailed studies of the structure and composition of complex oxides. The HAADF detector collects electrons

  10. Ion-induced electron emission microscopy

    DOE Patents [OSTI]

    Doyle, Barney L.; Vizkelethy, Gyorgy; Weller, Robert A.

    2001-01-01

    An ion beam analysis system that creates multidimensional maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the secondary electrons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted secondary electrons are collected in a strong electric field perpendicular to the sample surface and (optionally) projected and refocused by the electron lenses found in a photon emission electron microscope, amplified by microchannel plates and then their exact position is sensed by a very sensitive X Y position detector. Position signals from this secondary electron detector are then correlated in time with nuclear, atomic or electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these secondary electrons in the fit place.

  11. Phase contrast in high resolution electron microscopy

    DOE Patents [OSTI]

    Rose, H.H.

    1975-09-23

    This patent relates to a device for developing a phase contrast signal for a scanning transmission electron microscope. The lens system of the microscope is operated in a condition of defocus so that predictable alternate concentric regions of high and low electron density exist in the cone of illumination. Two phase detectors are placed beneath the object inside the cone of illumination, with the first detector having the form of a zone plate, each of its rings covering alternate regions of either higher or lower electron density. The second detector is so configured that it covers the regions of electron density not covered by the first detector. Each detector measures the number of electrons incident thereon and the signal developed by the first detector is subtracted from the signal developed by the record detector to provide a phase contrast signal. (auth)

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

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

    Department of Energy 1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation es095_unocic_2011_o.pdf (1.17 MB) More Documents & Publications In-Situ Electron Microscopy of Electrical Energy Storage Materials In-Situ Electron Microscopy of Electrical Energy Storage Materials In-situ characterization and diagnostics of mechanical degradation in electrodes

  13. Ultra-High Resolution Electron Microscopy for Catalyst Characterization |

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

    Department of Energy lm034_rohatgi_2011_o.pdf (1.05 MB) More Documents & Publications Vehicle Technologies Office: 2010 Lightweight Materials R&D Annual Progress Report Nanostructured Materials by Machining 2011 Annual Progress Report for Lightweighting Materials Department of Energy

    pm029_allard_2011_p.pdf (2.39 MB) More Documents & Publications Ultra-High Resolution Electron Microscopy for Catalyst Characterization Ultra-high Resolution Electron Microscopy for Catalyst

  14. 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.

    2011-01-01

    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.

  15. Microscopy with slow electrons: from LEEM to XPEEM

    ScienceCinema (OSTI)

    Bauer, Ernst [Arizona State University, Phoenix, Arizona, United States

    2010-01-08

    The short penetration and escape depth of electrons with energies below 1 keV make them ideally suited for the study of surfaces and ultrathin films. The combination of the low energy electrons and the high lateral resolution of a microscope produces a powerful method for the characterization of nanostructures on bulk samples, in particular if the microscope is equipped with an imaging energy filter and connected to a synchrotron radiation source. Comprehensive characterization by imaging, diffraction, and spectroscope of the structural, chemical, and magnetic properties is then possible. The Talk will describe the various imaging techniques in using reflected and emitted electrons in low-energy electron microscopy (LEEM) and x-ray photoemission electron microscopy (XPEEM), with an emphasis on magnetic materials with spin-polarized LEEM and x-ray magnetic circular dichroism PEEM. The talk with end with an outlook on future possibilities.

  16. A national facility for biological cryo-electron microscopy

    SciTech Connect (OSTI)

    Saibil, Helen R.; Grnewald, Kay; Stuart, David I.

    2015-01-01

    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.

  17. Microfabricated high-bandpass foucault aperture for electron microscopy

    DOE Patents [OSTI]

    Glaeser, Robert; Cambie, Rossana; Jin, Jian

    2014-08-26

    A variant of the Foucault (knife-edge) aperture is disclosed that is designed to provide single-sideband (SSB) contrast at low spatial frequencies but retain conventional double-sideband (DSB) contrast at high spatial frequencies in transmission electron microscopy. The aperture includes a plate with an inner open area, a support extending from the plate at an edge of the open area, a half-circle feature mounted on the support and located at the center of the aperture open area. The radius of the half-circle portion of reciprocal space that is blocked by the aperture can be varied to suit the needs of electron microscopy investigation. The aperture is fabricated from conductive material which is preferably non-oxidizing, such as gold, for example.

  18. Studying localized corrosion using liquid cell transmission electron microscopy

    SciTech Connect (OSTI)

    Chee, See Wee; Pratt, Sarah H.; Hattar, Khalid; Duquette, David; Ross, Frances M.; Hull, Robert

    2014-11-07

    Using liquid cell transmission electron microscopy (LCTEM), localized corrosion of Cu and Al thin films immersed in aqueous NaCl solutions was studied. We demonstrate that potentiostatic control can be used to initiate pitting and that local compositional changes, due to focused ion beam implantation of Au+ ions, can modify the corrosion susceptibility of Al films. Likewise, a discussion on strategies to control the onset of pitting is also presented.

  19. Studying localized corrosion using liquid cell transmission electron microscopy

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

    Chee, See Wee; Pratt, Sarah H.; Hattar, Khalid; Duquette, David; Ross, Frances M.; Hull, Robert

    2014-11-07

    Using liquid cell transmission electron microscopy (LCTEM), localized corrosion of Cu and Al thin films immersed in aqueous NaCl solutions was studied. We demonstrate that potentiostatic control can be used to initiate pitting and that local compositional changes, due to focused ion beam implantation of Au+ ions, can modify the corrosion susceptibility of Al films. Likewise, a discussion on strategies to control the onset of pitting is also presented.

  20. Focused ion beam and scanning electron microscopy for 3D materials...

    Office of Scientific and Technical Information (OSTI)

    microscopy for 3D materials characterization. Citation Details In-Document Search Title: Focused ion beam and scanning electron microscopy for 3D materials characterization. ...

  1. System and method for compressive scanning electron microscopy

    DOE Patents [OSTI]

    Reed, Bryan W

    2015-01-13

    A scanning transmission electron microscopy (STEM) system is disclosed. The system may make use of an electron beam scanning system configured to generate a plurality of electron beam scans over substantially an entire sample, with each scan varying in electron-illumination intensity over a course of the scan. A signal acquisition system may be used for obtaining at least one of an image, a diffraction pattern, or a spectrum from the scans, the image, diffraction pattern, or spectrum representing only information from at least one of a select subplurality or linear combination of all pixel locations comprising the image. A dataset may be produced from the information. A subsystem may be used for mathematically analyzing the dataset to predict actual information that would have been produced by each pixel location of the image.

  2. Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography

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

    Jesse, S.; Chi, M.; Belianinov, A.; Beekman, C.; Kalinin, S. V.; Borisevich, A. Y.; Lupini, A. R.

    2016-05-23

    Electron microscopy is undergoing a transition; from the model of producing only a few micrographs, through the current state where many images and spectra can be digitally recorded, to a new mode where very large volumes of data (movies, ptychographic and multi-dimensional series) can be rapidly obtained. In this paper, we discuss the application of so-called “big-data” methods to high dimensional microscopy data, using unsupervised multivariate statistical techniques, in order to explore salient image features in a specific example of BiFeO3 domains. Remarkably, k-means clustering reveals domain differentiation despite the fact that the algorithm is purely statistical in nature andmore » does not require any prior information regarding the material, any coexisting phases, or any differentiating structures. While this is a somewhat trivial case, this example signifies the extraction of useful physical and structural information without any prior bias regarding the sample or the instrumental modality. Further interpretation of these types of results may still require human intervention. Finally, however, the open nature of this algorithm and its wide availability, enable broad collaborations and exploratory work necessary to enable efficient data analysis in electron microscopy.« less

  3. Time resolved electron microscopy for in situ experiments

    SciTech Connect (OSTI)

    Campbell, Geoffrey H. McKeown, Joseph T.; Santala, Melissa K.

    2014-12-15

    Transmission electron microscopy has functioned for decades as a platform for in situ observation of materials and processes with high spatial resolution. Yet, the dynamics often remain elusive, as they unfold too fast to discern at these small spatial scales under traditional imaging conditions. Simply shortening the exposure time in hopes of capturing the action has limitations, as the number of electrons will eventually be reduced to the point where noise overtakes the signal in the image. Pulsed electron sources with high instantaneous current have successfully shortened exposure times (thus increasing the temporal resolution) by about six orders of magnitude over conventional sources while providing the necessary signal-to-noise ratio for dynamic imaging. We describe here the development of this new class of microscope and the principles of its operation, with examples of its application to problems in materials science.

  4. High-resolution electron microscopy of advanced materials

    SciTech Connect (OSTI)

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  5. Electron microscopy study of direct laser deposited IN718

    SciTech Connect (OSTI)

    Ding, R.G.; Huang, Z.W.; Li, H.Y.; Mitchell, I.; Baxter, G.; Bowen, P.

    2015-08-15

    The microstructure of direct laser deposited (DLD) IN718 has been investigated in detail using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results confirm that the dendrite core microstructure can be linked to the cooling rate experienced during the deposition. A ~ 100 μm wide δ partially dissolved region in the IN718 substrate was observed close to the substrate/deposit boundary. In the deposited IN718, γ/Laves eutectic constituent is the predominant minor microconstituent. Irregular and regular (small) (Nb,Ti)C carbides and a mixture of the carbides and Laves were observed. Most M{sub 3}B{sub 2} borides were nucleated around a (Nb,Ti)C carbide. Needles of δ phase precipitated from the Laves phase were also observed. A complex constituent (of Laves, δ, α-Cr, γ″, and γ matrix) is reported in IN718 for the first time. The formation of α-Cr particles could be related to Cr rejection during the formation and growth of Cr-depleted δ phase. - Highlights: • Secondary phases in IN718 deposits were identified using electron diffraction and EDS. • MC, M{sub 3}B{sub 2}, γ/Laves eutectic and γ/NbC/Laves eutectic were observed. • Needle-like δ phases were precipitated from the Laves phase. • A complex constituent (Laves, δ, α-Cr, γ″ and γ) was reported for the first time.

  6. Simultaneous orientation and thickness mapping in transmission electron microscopy

    SciTech Connect (OSTI)

    Tyutyunnikov, Dmitry; Özdöl, V. Burak; Koch, Christoph T.

    2014-12-04

    In this paper we introduce an approach for simultaneous thickness and orientation mapping of crystalline samples by means of transmission electron microscopy. We show that local thickness and orientation values can be extracted from experimental dark-field (DF) image data acquired at different specimen tilts. The method has been implemented to automatically acquire the necessary data and then map thickness and crystal orientation for a given region of interest. We have applied this technique to a specimen prepared from a commercial semiconductor device, containing multiple 22 nm technology transistor structures. The performance and limitations of our method are discussed and compared to those of other techniques available.

  7. Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series

    SciTech Connect (OSTI)

    Dahmen, Tim; Baudoin, Jean-Pierre G; Lupini, Andrew R; Kubel, Christian; Slusallek, Phillip; De Jonge, Niels

    2014-01-01

    In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller missing wedge artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.

  8. Frontiers of in situ electron microscopy

    SciTech Connect (OSTI)

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

    2015-01-01

    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.

  9. Collaborative Computational Project for Electron cryo-Microscopy

    SciTech Connect (OSTI)

    Wood, Chris; Burnley, Tom [Science and Technology Facilities Council, Research Complex at Harwell, Didcot OX11 0FA (United Kingdom); Patwardhan, Ardan [European Molecular Biology Laboratory, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD (United Kingdom); Scheres, Sjors [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Topf, Maya [University of London, Malet Street, London WC1E 7HX (United Kingdom); Roseman, Alan [University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom); Winn, Martyn, E-mail: martyn.winn@stfc.ac.uk [Science and Technology Facilities Council, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Science and Technology Facilities Council, Research Complex at Harwell, Didcot OX11 0FA (United Kingdom)

    2015-01-01

    The Collaborative Computational Project for Electron cryo-Microscopy (CCP-EM) is a new initiative for the structural biology community, following the success of CCP4 for macromolecular crystallography. Progress in supporting the users and developers of cryoEM software is reported. The Collaborative Computational Project for Electron cryo-Microscopy (CCP-EM) has recently been established. The aims of the project are threefold: to build a coherent cryoEM community which will provide support for individual scientists and will act as a focal point for liaising with other communities, to support practising scientists in their use of cryoEM software and finally to support software developers in producing and disseminating robust and user-friendly programs. The project is closely modelled on CCP4 for macromolecular crystallography, and areas of common interest such as model fitting, underlying software libraries and tools for building program packages are being exploited. Nevertheless, cryoEM includes a number of techniques covering a large range of resolutions and a distinct project is required. In this article, progress so far is reported and future plans are discussed.

  10. In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry

    SciTech Connect (OSTI)

    Graetz J.; Meng, Y.S.; McGilvray, T.; Yang, M.-C.; Gostovic, D.; Wang, F.; Zeng, D.; Zhu, Y.

    2011-10-31

    Oxides and their tailored structures are at the heart of electrochemical energy storage technologies and advances in understanding and controlling the dynamic behaviors in the complex oxides, particularly at the interfaces, during electrochemical processes will catalyze creative design concepts for new materials with enhanced and better-understood properties. Such knowledge is not accessible without new analytical tools. New innovative experimental techniques are needed for understanding the chemistry and structure of the bulk and interfaces, more importantly how they change with electrochemical processes in situ. Analytical Transmission Electron Microscopy (TEM) is used extensively to study electrode materials ex situ and is one of the most powerful tools to obtain structural, morphological, and compositional information at nanometer scale by combining imaging, diffraction and spectroscopy, e.g., EDS (energy dispersive X-ray spectrometry) and Electron Energy Loss Spectrometry (EELS). Determining the composition/structure evolution upon electrochemical cycling at the bulk and interfaces can be addressed by new electron microscopy technique with which one can observe, at the nanometer scale and in situ, the dynamic phenomena in the electrode materials. In electrochemical systems, for instance in a lithium ion battery (LIB), materials operate under conditions that are far from equilibrium, so that the materials studied ex situ may not capture the processes that occur in situ in a working battery. In situ electrochemical operation in the ultra-high vacuum column of a TEM has been pursued by two major strategies. In one strategy, a 'nano-battery' can be fabricated from an all-solid-state thin film battery using a focused ion beam (FIB). The electrolyte is either polymer based or ceramic based without any liquid component. As shown in Fig. 1a, the interfaces between the active electrode material/electrolyte can be clearly observed with TEM imaging, in contrast to the

  11. Advanced analytical electron microscopy for alkali-ion batteries

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

    Qian, Danna; Ma, Cheng; Meng, Ying Shirley; More, Karren; Chi, Miaofang

    2015-01-01

    Lithium-ion batteries are a leading candidate for electric vehicle and smart grid applications. However, further optimizations of the energy/power density, coulombic efficiency and cycle life are still needed, and this requires a thorough understanding of the dynamic evolution of each component and their synergistic behaviors during battery operation. With the capability of resolving the structure and chemistry at an atomic resolution, advanced analytical transmission electron microscopy (AEM) is an ideal technique for this task. The present review paper focuses on recent contributions of this important technique to the fundamental understanding of the electrochemical processes of battery materials. A detailed reviewmore » of both static (ex situ) and real-time (in situ) studies will be given, and issues that still need to be addressed will be discussed.« less

  12. Simultaneous orientation and thickness mapping in transmission electron microscopy

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

    Tyutyunnikov, Dmitry; Özdöl, V. Burak; Koch, Christoph T.

    2014-12-04

    In this paper we introduce an approach for simultaneous thickness and orientation mapping of crystalline samples by means of transmission electron microscopy. We show that local thickness and orientation values can be extracted from experimental dark-field (DF) image data acquired at different specimen tilts. The method has been implemented to automatically acquire the necessary data and then map thickness and crystal orientation for a given region of interest. We have applied this technique to a specimen prepared from a commercial semiconductor device, containing multiple 22 nm technology transistor structures. The performance and limitations of our method are discussed and comparedmore » to those of other techniques available.« less

  13. Advanced analytical electron microscopy for alkali-ion batteries

    SciTech Connect (OSTI)

    Qian, Danna; Ma, Cheng; Meng, Ying Shirley; More, Karren; Chi, Miaofang

    2015-01-01

    Lithium-ion batteries are a leading candidate for electric vehicle and smart grid applications. However, further optimizations of the energy/power density, coulombic efficiency and cycle life are still needed, and this requires a thorough understanding of the dynamic evolution of each component and their synergistic behaviors during battery operation. With the capability of resolving the structure and chemistry at an atomic resolution, advanced analytical transmission electron microscopy (AEM) is an ideal technique for this task. The present review paper focuses on recent contributions of this important technique to the fundamental understanding of the electrochemical processes of battery materials. A detailed review of both static (ex situ) and real-time (in situ) studies will be given, and issues that still need to be addressed will be discussed.

  14. Thin dielectric film thickness determination by advanced transmission electron microscopy

    SciTech Connect (OSTI)

    Diebold, A.C.; Foran, B.; Kisielowski, C.; Muller, D.; Pennycook, S.; Principe, E.; Stemmer, S.

    2003-09-01

    High Resolution Transmission Electron Microscopy (HR-TEM) has been used as the ultimate method of thickness measurement for thin films. The appearance of phase contrast interference patterns in HR-TEM images has long been confused as the appearance of a crystal lattice by non-specialists. Relatively easy to interpret crystal lattice images are now directly observed with the introduction of annular dark field detectors for scanning TEM (STEM). With the recent development of reliable lattice image processing software that creates crystal structure images from phase contrast data, HR-TEM can also provide crystal lattice images. The resolution of both methods was steadily improved reaching now into the sub Angstrom region. Improvements in electron lens and image analysis software are increasing the spatial resolution of both methods. Optimum resolution for STEM requires that the probe beam be highly localized. In STEM, beam localization is enhanced by selection of the correct aperture. When STEM measurement is done using a highly localized probe beam, HR-TEM and STEM measurement of the thickness of silicon oxynitride films agree within experimental error. In this paper, the optimum conditions for HR-TEM and STEM measurement are discussed along with a method for repeatable film thickness determination. The impact of sample thickness is also discussed. The key result in this paper is the proposal of a reproducible method for film thickness determination.

  15. Imaging doped silicon test structures using low energy electron microscopy.

    SciTech Connect (OSTI)

    Nakakura, Craig Yoshimi; Anderson, Meredith Lynn; Kellogg, Gary Lee

    2010-01-01

    This document is the final SAND Report for the LDRD Project 105877 - 'Novel Diagnostic for Advanced Measurements of Semiconductor Devices Exposed to Adverse Environments' - funded through the Nanoscience to Microsystems investment area. Along with the continuous decrease in the feature size of semiconductor device structures comes a growing need for inspection tools with high spatial resolution and high sample throughput. Ideally, such tools should be able to characterize both the surface morphology and local conductivity associated with the structures. The imaging capabilities and wide availability of scanning electron microscopes (SEMs) make them an obvious choice for imaging device structures. Dopant contrast from pn junctions using secondary electrons in the SEM was first reported in 1967 and more recently starting in the mid-1990s. However, the serial acquisition process associated with scanning techniques places limits on the sample throughput. Significantly improved throughput is possible with the use of a parallel imaging scheme such as that found in photoelectron emission microscopy (PEEM) and low energy electron microscopy (LEEM). The application of PEEM and LEEM to device structures relies on contrast mechanisms that distinguish differences in dopant type and concentration. Interestingly, one of the first applications of PEEM was a study of the doping of semiconductors, which showed that the PEEM contrast was very sensitive to the doping level and that dopant concentrations as low as 10{sup 16} cm{sup -3} could be detected. More recent PEEM investigations of Schottky contacts were reported in the late 1990s by Giesen et al., followed by a series of papers in the early 2000s addressing doping contrast in PEEM by Ballarotto and co-workers and Frank and co-workers. In contrast to PEEM, comparatively little has been done to identify contrast mechanisms and assess the capabilities of LEEM for imaging semiconductor device strictures. The one exception is the

  16. Transmission electron microscopy analysis of corroded metal waste forms.

    SciTech Connect (OSTI)

    Dietz, N. L.

    2005-04-15

    This report documents the results of analyses with transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDS) and selected area electron diffraction (ED) of samples of metallic waste form (MWF) materials that had been subjected to various corrosion tests. The objective of the TEM analyses was to characterize the composition and microstructure of surface alteration products which, when combined with other test results, can be used to determine the matrix corrosion mechanism. The examination of test samples generated over several years has resulted in refinements to the TEM sample preparation methods developed to preserve the orientation of surface alteration layers and the underlying base metal. The preservation of microstructural spatial relationships provides valuable insight for determining the matrix corrosion mechanism and for developing models to calculate radionuclide release in repository performance models. The TEM results presented in this report show that oxide layers are formed over the exposed steel and intermetallic phases of the MWF during corrosion in aqueous solutions and humid air at elevated temperatures. An amorphous non-stoichiometric ZrO{sub 2} layer forms at the exposed surfaces of the intermetallic phases, and several nonstoichiometric Fe-O layers form over the steel phases in the MWF. These oxide layers adhere strongly to the underlying metal, and may be overlain by one or more crystalline Fe-O phases that probably precipitated from solution. The layer compositions are consistent with a corrosion mechanism of oxidative dissolution of the steel and intermetallic phases. The layers formed on the steel and intermetallic phases form a continuous layer over the exposed waste form, although vertical splits in the layer and corrosion in pits and crevices were seen in some samples. Additional tests and analyses are needed to verify that these layers passivate the underlying metals and if passivation can break

  17. TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS

    SciTech Connect (OSTI)

    Tosten, M; Michael Morgan, M

    2008-12-12

    A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing {delta} ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal {delta} ferrite. In welds with higher levels of {delta} ferrite, the ferrite was more continuous and, in some areas of the 33 volume percent sample, was the matrix/majority phase. The helium bubble microstructures observed were similar in all samples. Bubbles were found in the austenite but not in the {delta} ferrite. In the austenite, bubbles had nucleated homogeneously in the grain interiors and heterogeneously on dislocations. Bubbles were not found on any austenite/austenite grain boundaries or at the austenite/{delta} ferrite interphase interfaces. Bubbles were not observed in the {delta} ferrite because of the combined effects of the low solubility and rapid diffusion of tritium through the {delta} ferrite which limited the amount of helium present to form visible bubbles.

  18. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing...

  19. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were...

  20. A TRANSMISSION ELECTRON MICROSCOPY STUDY OF PRESOLAR HIBONITE

    SciTech Connect (OSTI)

    Zega, Thomas J.; Stroud, Rhonda M.; Alexander, Conel M. O'D.; Nittler, Larry R.

    2011-04-01

    We report isotopic and microstructural data on five presolar hibonite grains (KH1, KH2, KH6, KH15, and KH21) identified in an acid residue of the Krymka LL3.1 ordinary chondrite. Isotopic measurements by secondary ion mass spectrometry (SIMS) verified a presolar circumstellar origin for the grains. Transmission electron microscopy (TEM) examination of the crystal structure and chemistry of the grains was enabled by in situ sectioning and lift-out with a focused-ion-beam scanning-electron microscope (FIB-SEM). Comparisons of isotopic compositions with models indicate that four of the five grains formed in low-mass stars that evolved through the red giant/asymptotic giant branches (RGBs/AGBs), whereas one grain formed in the ejecta of a Type II supernova. Selected-area electron-diffraction patterns show that all grains are single crystals of hibonite. Some grains contain minor structural perturbations (stacking faults) and small spreads in orientation that can be attributed to a combination of growth defects and mechanical processing by grain-grain collisions. The similar structure of the supernova grain to those from RGB/AGB stars indicates a similarity in the formation conditions. Radiation damage (e.g., point defects), if present, occurs below our detection limit. Of the five grains we studied, only one has the pure hibonite composition of CaAl{sub 12}O{sub 19}. All others contain minor amounts of Mg, Si, Ti, and Fe. The microstructural data are generally consistent with theoretical predictions, which constrain the circumstellar condensation temperature to a range of 1480-1743 K, assuming a corresponding total gas pressure between 1 x 10{sup -6} and 1 x 10{sup -3} atm. The TEM data were also used to develop a calibration for SIMS determination of Ti contents in oxide grains. Grains with extreme {sup 18}O depletions, indicating deep mixing has occurred in their parent AGB stars, are slightly Ti enriched compared with grains from stars without deep mixing, most

  1. Transmission electron microscopy of whiskers and hillocks formed on Al films deposited onto a glass

    SciTech Connect (OSTI)

    Saka, H.; Fujino, S.; Kuroda, K. [Department of Quantum Engineering, Nagoya University, Nagoya 464-01 (Japan); Tsujimoto, K.; Tsuji, S. [Display Technology, IBM Japan, Ltd., Shimotsuruma, Yamato, Kanagawa 242 (Japan); Takatsuji, H. [Display Technology, IBM Japan, Ltd., Ichimiyake, Yasu-gun, Shiga 520-23 (Japan)

    1998-01-05

    Whiskers and hillocks formed on an Al film deposited onto a glass substrate have been observed by means of a variety of transmission electron microscopy technique.

  2. New insights from in-situ electron microscopy into capacity loss...

    Office of Scientific and Technical Information (OSTI)

    Li-ion batteries with Al anodes. Citation Details In-Document Search Title: New insights from in-situ electron microscopy into capacity loss mechanisms in Li-ion batteries with Al ...

  3. New insights from in-situ electron microscopy into capacity loss...

    Office of Scientific and Technical Information (OSTI)

    batteries with Al anodes. Citation Details In-Document Search Title: New insights from in-situ electron microscopy into capacity loss mechanisms in all-solid-state Li-ion batteries ...

  4. Electron and Scanning Probe Microscopies | U.S. DOE Office of Science (SC)

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

    Electron and Scanning Probe Microscopies Materials Sciences and Engineering (MSE) Division MSE Home About Research Areas Energy Frontier Research Centers (EFRCs) DOE Energy Innovation Hubs BES Funding Opportunities Reports and Activities Science Highlights Principal Investigators' Meetings BES Home Research Areas Electron and Scanning Probe Microscopies Print Text Size: A A A FeedbackShare Page This research area supports basic research in condensed matter physics and materials physics using

  5. In-Situ Electrochemical Transmission Electron Microscopy for Battery Research

    SciTech Connect (OSTI)

    Mehdi, Beata L; Gu, Meng; Parent, Lucas; Xu, WU; Nasybulin, Eduard; Chen, Xilin; Unocic, Raymond R; Xu, Pinghong; Welch, David; Abellan, Patricia; Zhang, Ji-Guang; Liu, Jun; Wang, Chongmin; Arslan, Ilke; Evans, James E; Browning, Nigel

    2014-01-01

    The recent development of in-situ liquid stages for (scanning) transmission electron microscopes now makes it possible for us to study the details of electrochemical processes under operando conditions. As electrochemical processes are complex, care must be taken to calibrate the system before any in-situ/operando observations. In addition, as the electron beam can cause effects that look similar to electrochemical processes at the electrolyte/electrode interface, an understanding of the role of the electron beam in modifying the operando observations must also be understood. In this paper we describe the design, assembly, and operation of an in-situ electrochemical cell, paying particular attention to the method for controlling and quantifying the experimental parameters. The use of this system is then demonstrated for the lithiation/delithiation of silicon nanowires.

  6. Electron microscopy of Mg/TiO{sub 2} photocatalyst morphology for deep desulfurization of diesel

    SciTech Connect (OSTI)

    Yin, Yee Cia; Kait, Chong Fai Fatimah, Hayyiratul Wilfred, Cecilia

    2015-07-22

    A series of Mg/TiO{sub 2} photocatalysts were prepared and characterized using Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Transmission Electron Microscopy (HRTEM). The average particle sizes of the photocatalysts were ranging from 25.7 to 35.8 nm. Incorporation of Mg on TiO{sub 2} did not lead to any surface lattice distortion to TiO{sub 2}. HRTEM data indicated the presence of MgO and Mg(OH){sub 2} mixture at low Mg loading while at higher Mg loading, the presence of lamellar Mg-oxyhydroxide intermediates and Mg(OH){sub 2}.

  7. Characterization of aluminum oxide tunnel barriers by combining transport measurements and transmission electron microscopy imaging

    SciTech Connect (OSTI)

    Aref, T.; Averin, A.; Nguyend, H. Q.; Pekola, J. P.; Dijken, S. van; Yao, L. D.; Ferring, A.; Koberidze, M.; Nieminen, R. M.

    2014-08-21

    We present two approaches for studying the uniformity of a tunnel barrier. The first approach is based on measuring single-electron and two-electron tunneling in a hybrid single-electron transistor. Our measurements indicate that the effective area of a conduction channel is about one order of magnitude larger than predicted by theoretical calculations. With the second method, transmission electron microscopy, we demonstrate that variations in the barrier thickness are a plausible explanation for the larger effective area and an enhancement of higher order tunneling processes.

  8. High-Resolution Transmission Electron Microscopy Observation of Colloidal Nanocrystal Growth Mechanisms using Graphene Liquid Cells

    SciTech Connect (OSTI)

    Yuk, Jong Min; Park, Jungwon; Ercius, Peter; Kim, Kwanpyo; Hellebusch, Danny J.; Crommie, Michael F.; Lee, Jeong Yong; Zettl, A.; Alivisatos, A. Paul

    2011-12-12

    We introduce a new type of liquid cell for in-situ electron microscopy based upon entrapment of a liquid film between layers of graphene. We employ this cell to achieve high-resolution imaging of colloidal platinum nanocrystal growth. The ability to directly image and resolve critical steps at atomic resolution provides new insights into nanocrystal coalescence and reshaping during growth.

  9. Investigating the mesostructure of ordered porous silica nanocomposites by transmission electron microscopy techniques

    SciTech Connect (OSTI)

    Bullita, S.; Casula, M. F.; Piludu, M.; Falqui, A.; Carta, D.; Corrias, A.

    2014-10-21

    Nanocomposites made out of FeCo alloy nanocrystals supported onto pre-formed mesoporous ordered silica which features a cubic arrangement of pores (SBA-16) were investigated. Information on the effect of the nanocrystals on the mesostructure (i.e. pore arrangement symmetry, pore size, and shape) were deduced by a multitechnique approach including N2 physisorption, low angle X-ray diffraction, and Transmission electron microscopy. It is shown that advanced transmission electron microscopy techniques are required, however, to gain direct evidence on key compositional and textural features of the nanocomposites. In particular, electron tomography and microtomy techniques make clear that the FeCo nanocrystals are located within the pores of the SBA-16 silica, and that the ordered mesostructure of the nanocomposite is retained throughout the observed specimen.

  10. Imaging and microanalysis of thin ionomer layers by scanning transmission electron microscopy

    SciTech Connect (OSTI)

    Cullen, David A; Koestner, Roland; Kukreja, Ratan; Minko, Sergiy; Trotsenko, Oleksandr; Tokarev, Alexander V; Guetaz, Laure; Meyer III, Harry M; Parish, Chad M; More, Karren Leslie

    2014-01-01

    Improved conditions for imaging and spectroscopic mapping of thin perfluorosulfonic acid (PFSA) ionomer layers in fuel cell electrodes by scanning transmission electron microscopy (STEM) have been investigated. These conditions are first identified on model systems of Nafion ionomer-coated nanostructured thin films and nanoporous Si. The optimized conditions are then applied in a quantitative study of the ionomer through-layer loading for two typical electrode catalyst coatings using electron energy loss and energy dispersive X-ray spectroscopy in the transmission electron microscope. The e-beam induced damage to the perfluorosulfonic acid (PFSA) ionomer is quantified by following the fluorine mass loss with electron exposure and is then mitigated by a few orders of magnitude using cryogenic specimen cooling and a higher incident electron voltage. Multivariate statistical analysis is also applied to the analysis of spectrum images for data denoising and unbiased separation of independent components related to the catalyst, ionomer, and support.

  11. Thickness determination of few-layer hexagonal boron nitride films by scanning electron microscopy and Auger electron spectroscopy

    SciTech Connect (OSTI)

    Sutter, P. Sutter, E.

    2014-09-01

    We assess scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) for thickness measurements on few-layer hexagonal boron nitride (h-BN), the layered dielectric of choice for integration with graphene and other two-dimensional materials. Observations on h-BN islands with large, atomically flat terraces show that the secondary electron intensity in SEM reflects monolayer height changes in films up to least 10 atomic layers thickness. From a quantitative analysis of AES data, the energy-dependent electron escape depth in h-BN films is deduced. The results show that AES is suitable for absolute thickness measurements of few-layer h-BN of 1 to 6 layers.

  12. Nanoscale deformation analysis with high-resolution transmission electron microscopy and digital image correlation

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

    Wang, Xueju; Pan, Zhipeng; Fan, Feifei; Wang, Jiangwei; Liu, Yang; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-09-10

    We present an application of the digital image correlation (DIC) method to high-resolution transmission electron microscopy (HRTEM) images for nanoscale deformation analysis. The combination of DIC and HRTEM offers both the ultrahigh spatial resolution and high displacement detection sensitivity that are not possible with other microscope-based DIC techniques. We demonstrate the accuracy and utility of the HRTEM-DIC technique through displacement and strain analysis on amorphous silicon. Two types of error sources resulting from the transmission electron microscopy (TEM) image noise and electromagnetic-lens distortions are quantitatively investigated via rigid-body translation experiments. The local and global DIC approaches are applied for themore » analysis of diffusion- and reaction-induced deformation fields in electrochemically lithiated amorphous silicon. As a result, the DIC technique coupled with HRTEM provides a new avenue for the deformation analysis of materials at the nanometer length scales.« less

  13. Nanoscale deformation analysis with high-resolution transmission electron microscopy and digital image correlation

    SciTech Connect (OSTI)

    Wang, Xueju; Pan, Zhipeng; Fan, Feifei; Wang, Jiangwei; Liu, Yang; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-09-10

    We present an application of the digital image correlation (DIC) method to high-resolution transmission electron microscopy (HRTEM) images for nanoscale deformation analysis. The combination of DIC and HRTEM offers both the ultrahigh spatial resolution and high displacement detection sensitivity that are not possible with other microscope-based DIC techniques. We demonstrate the accuracy and utility of the HRTEM-DIC technique through displacement and strain analysis on amorphous silicon. Two types of error sources resulting from the transmission electron microscopy (TEM) image noise and electromagnetic-lens distortions are quantitatively investigated via rigid-body translation experiments. The local and global DIC approaches are applied for the analysis of diffusion- and reaction-induced deformation fields in electrochemically lithiated amorphous silicon. As a result, the DIC technique coupled with HRTEM provides a new avenue for the deformation analysis of materials at the nanometer length scales.

  14. In situ transmission electron microscopy of individual carbon nanotetrahedron/nanoribbon structures in Joule heating

    SciTech Connect (OSTI)

    Masuda, Yusuke; Yoshida, Hideto; Takeda, Seiji; Kohno, Hideo

    2014-08-25

    Collapse of a carbon nanotube results in the formation of a nanoribbon, and a switching of the collapse direction yields a nanotetrahedron in the middle of a nanoribbon. Here, we report in-situ transmission electron microscopy observations of the behavior of carbon nanotetrahedron/nanoribbon structures during Joule heating to reveal their thermal stability. In addition, we propose that the observed process is related to the formation process of the structure.

  15. Comparison of preparation techniques for nuclear materials for transmission electron microscopy (TEM)

    SciTech Connect (OSTI)

    Aitkaliyeva, Assel; Madden, James W.; Miller, Brandon D; Cole, James I; Gan, Jian

    2015-04-01

    Preparation of highly radioactive and irradiated nuclear fuels and materials for transmission electron microscopy (TEM) is conjoined with a set of unique challenges, including but not limited to personnel radiation exposure and contamination. The paper evaluates three specimen preparation techniques for preparation of irradiated materials and determines which technique yields to the most reliable characterization of radiation damage microstructure. Various specimen preparation artifacts associated with each technique are considered and ways of minimizing these artifacts are addressed.

  16. Conductive atomic force microscopy study of local electronic transport in ZnTe thin films

    SciTech Connect (OSTI)

    Kshirsagar, Sachin D.; Krishna, M. Ghanashyam; Tewari, Surya P.

    2013-02-05

    ZnTe thin films obtained by the electron beam evaporation technique were subjected to thermal annealing at 500 Degree-Sign C for 2 hours. The as deposited films were amorphous but transformed to the crystalline state under influence of the thermal treatment. There is increase in optical absorption due to the heat treatment caused by increase in free carrier concentration. Conductive atomic force microscopy shows the presence of electronic inhomogeneities in the films. This is attributed to local compositional variations in the films. I-V analysis in these systems indicates formation of Schottky junction at the metal semiconductor (M-S) interface.

  17. An In Situ Study of the Martensitic Transformation in Shape Memory Alloys Using Photoemission Electron Microscopy

    SciTech Connect (OSTI)

    Cai, Mingdong; Langford, Stephen C.; Dickinson, J. T.; Xiong, Gang; Droubay, Timothy C.; Joly, Alan G.; Beck, Kenneth M.; Hess, Wayne P.

    2007-04-15

    Thermally-induced martensitic phase transformations in polycrystalline CuZnAl and thin-film NiTiCu shape memory alloys were probed using photoemission electron microscopy (PEEM). Ultra-violet photoelectron spectroscopy shows a reversible change in the apparent work function during transformation, presumably due to the contrasting surface electronic structures of the martensite and austenite phases. In situ PEEM images provide information on the spatial distribution of these phases and the evolution of the surface microstructure during transformation. PEEM offers considerable potential for improving our understanding of martensitic transformations in shape memory alloys in real time.

  18. Defects in paramagnetic Co-doped ZnO films studied by transmission electron microscopy

    SciTech Connect (OSTI)

    Kovacs, Andras; Ney, A.; Duchamp, Martial; Ney, V.; Boothroyd, Chris; Galindo, Pedro L.; Kaspar, Tiffany C.; Chambers, Scott A.; Dunin-Borkowski, Rafal

    2013-12-23

    We have studied planar defects in epitaxial Co:ZnO dilute magnetic semiconductor thin films deposited on c-plane sapphire (Al2O3) and the Co:ZnO/Al2O3 interface structure at atomic resolution using aberration-corrected transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). Comparing Co:ZnO samples deposited by pulsed laser deposition and reactive magnetron sputtering, both exhibit extrinsic stacking faults, incoherent interface structures, and compositional variations within the first 3-4 Co:ZnO layers at the interface.. In addition, we have measured the local strain which reveals the lattice distortion around the stacking faults.

  19. Efficient linear phase contrast in scanning transmission electron microscopy with matched illumination and detector interferometry

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

    Ophus, Colin; Ciston, Jim; Pierce, Jordan; Harvey, Tyler R.; Chess, Jordan; McMorran, Benjamin J.; Czarnik, Cory; Rose, Harald H.; Ercius, Peter

    2016-02-29

    The ability to image light elements in soft matter at atomic resolution enables unprecedented insight into the structure and properties of molecular heterostructures and beam-sensitive nanomaterials. In this study, we introduce a scanning transmission electron microscopy technique combining a pre-specimen phase plate designed to produce a probe with structured phase with a high-speed direct electron detector to generate nearly linear contrast images with high efficiency. We demonstrate this method by using both experiment and simulation to simultaneously image the atomic-scale structure of weakly scattering amorphous carbon and strongly scattering gold nanoparticles. Our method demonstrates strong contrast for both materials, makingmore » it a promising candidate for structural determination of heterogeneous soft/hard matter samples even at low electron doses comparable to traditional phase-contrast transmission electron microscopy. Ultimately, simulated images demonstrate the extension of this technique to the challenging problem of structural determination of biological material at the surface of inorganic crystals.« less

  20. Nucleation of diamond by pure carbon ion bombardment--a transmission electron microscopy study

    SciTech Connect (OSTI)

    Yao, Y.; Liao, M.Y.; Wang, Z.G.; Lifshitz, Y.; Lee, S.

    2005-08-08

    A cross-sectional high-resolution transmission electron microscopy (HRTEM) study of a film deposited by a 1 keV mass-selected carbon ion beam onto silicon held at 800 deg. C is presented. Initially, a graphitic film with its basal planes perpendicular to the substrate is evolving. The precipitation of nanodiamond crystallites in upper layers is confirmed by HRTEM, selected area electron diffraction, and electron energy loss spectroscopy. The nucleation of diamond on graphitic edges as predicted by Lambrecht et al. [W. R. L. Lambrecht, C. H. Lee, B. Segall, J. C. Angus, Z. Li, and M. Sunkara, Nature, 364 607 (1993)] is experimentally confirmed. The results are discussed in terms of our recent subplantation-based diamond nucleation model.

  1. EMRinger: side chain–directed model and map validation for 3D cryo-electron microscopy

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

    Barad, Benjamin A.; Echols, Nathaniel; Wang, Ray Yu-Ruei; Cheng, Yifan; DiMaio, Frank; Adams, Paul D.; Fraser, James S.

    2015-08-17

    Advances in high-resolution cryo-electron microscopy (cryo-EM) require the development of validation metrics to independently assess map quality and model geometry. We report that EMRinger is a tool that assesses the precise fitting of an atomic model into the map during refinement and shows how radiation damage alters scattering from negatively charged amino acids. EMRinger (https://github.com/fraser-lab/EMRinger) will be useful for monitoring progress in resolving and modeling high-resolution features in cryo-EM.

  2. Structural defects in GaN revealed by Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Liliental-Weber, Zuzanna

    2014-04-18

    This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

  3. Structural defects in GaN revealed by Transmission Electron Microscopy

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

    Liliental-Weber, Zuzanna

    2014-09-08

    This paper reviews the various types of structural defects observed by Transmission Electron Microscopy in GaN heteroepitaxial layers grown on foreign substrates and homoepitaxial layers grown on bulk GaN substrates. The structural perfection of these layers is compared to the platelet self-standing crystals grown by High Nitrogen Pressure Solution. Defects in undoped and Mg doped GaN are discussed. Lastly, some models explaining the formation of inversion domains in heavily Mg doped layers that are possible defects responsible for the difficulties of p-doping in GaN are also reviewed.

  4. Studying The Kinetics Of Crystalline Silicon Nanoparticle Lithiation With In-Situ Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Mcdowell, Matthew T.; Ryu, Ill; Lee, Seokwoo; Wang, Chong M.; Nix, William D.; Cui, Yi

    2012-11-27

    Silicon is an attractive high-capacity anode material for Li-ion batteries, but a comprehensive understanding of the massive ~300% volume change and fracture during lithiation/delithiation is necessary to reliably employ Si anodes. Here, in-situ transmission electron microscopy (TEM) of the lithiation of crystalline Si nanoparticles reveals that the reaction slows down as it progresses into the particle interior. Analysis suggests that this behavior is due to the influence of mechanical stress at the reaction front on the driving force for the reaction. These experiments give insight into the factors controlling the kinetics of this unique reaction.

  5. Biological Applications and Transmission Electron Microscopy Investigations of Mesoporous Silica Nanoparticles

    SciTech Connect (OSTI)

    Brian G. Trewyn

    2006-05-01

    The research presented and discussed within involves the development of novel biological applications of mesoporous silica nanoparticles (MSN) and an investigation of mesoporous material by transmission electron microscopy (TEM). Mesoporous silica nanoparticles organically functionalized shown to undergo endocytosis in cancer cells and drug release from the pores was controlled intracellularly and intercellularly. Transmission electron microscopy investigations demonstrated the variety of morphologies produced in this field of mesoporous silica nanomaterial synthesis. A series of room-temperature ionic liquid (RTIL) containing mesoporous silica nanoparticle (MSN) materials with various particle morphologies, including spheres, ellipsoids, rods, and tubes, were synthesized. By changing the RTIL template, the pore morphology was tuned from the MCM-41 type of hexagonal mesopores to rotational moire type of helical channels, and to wormhole-like porous structures. These materials were used as controlled release delivery nanodevices to deliver antibacterial ionic liquids against Escherichia coli K12. The involvement of a specific organosiloxane function group, covalently attached to the exterior of fluorescein doped mesoporous silica nanoparticles (FITC-MSN), on the degree and kinetics of endocytosis in cancer and plant cells was investigated. The kinetics of endocystosis of TEG coated FITC-MSN is significantly quicker than FITC-MSN as determined by flow cytometry experiments. The fluorescence confocal microscopy investigation showed the endocytosis of TEG coated-FITC MSN triethylene glycol grafted fluorescein doped MSN (TEG coated-FITC MSN) into both KeLa cells and Tobacco root protoplasts. Once the synthesis of a controlled-release delivery system based on MCM-41-type mesoporous silica nanorods capped by disulfide bonds with superparamagnetic iron oxide nanoparticles was completed. The material was characterized by general methods and the dosage and kinetics of the

  6. In situ transmission electron microscopy analysis of conductive filament during solid electrolyte resistance switching

    SciTech Connect (OSTI)

    Fujii, Takashi; Arita, Masashi; Takahashi, Yasuo; Fujiwara, Ichiro

    2011-05-23

    An in situ transmission electron microscopy (TEM) analysis of a solid electrolyte, Cu-GeS, during resistance switching is reported. Real-time observations of the filament formation and disappearance process were performed in the TEM instrument and the conductive-filament-formation model was confirmed experimentally. Narrow conductive filaments were formed corresponding to resistance switching from high- to low-resistance states. When the resistance changed to high-resistance state, the filament disappeared. It was also confirmed by use of selected area diffractometry and energy-dispersive x-ray spectroscopy that the conductive filament was made of nanocrystals composed mainly of Cu.

  7. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy

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

    He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao -Qing; et al

    2016-05-09

    In this study, spinel transition metal oxides are an important class of materials that are being considered as electrodes for lithium-ion batteries, due to their low cost and high theoretical capacity. The lithiation of these compounds is known to undergo a two-step reaction, whereby intercalation and conversion occur in a sequential fashion. These two reactions are known to have distinct reaction dynamics, but it is unclear how the kinetics of these processes affect the overall electrochemical response. Here, we explore the lithiation of nanosized magnetite (Fe3O4) by employing a new strain-sensitive, bright-field scanning transmission electron microscopy approach.

  8. Hetero-epitaxial EuO interfaces studied by analytic electron microscopy

    SciTech Connect (OSTI)

    Mundy, Julia A.; Hodash, Daniel; Melville, Alexander; Held, Rainer; Mairoser, Thomas; Schmehl, Andreas; Muller, David A.; Kourkoutis, Lena F.; Schlom, Darrell G.

    2014-03-03

    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.

  9. An electron microscopy study of the microstructure and microarchitecture of the Strombus gigas shell

    SciTech Connect (OSTI)

    Rieke, P.C.; Laraia, V.J. ); Heuer, A.H. ); Aindow, M. )

    1989-11-01

    A scanning and transmission electron microscopy study is presented of the microstructure of the Strombus gigas shell. The hierarchical nature of this crossed-lamellar structure and the defect content of the mineral component are described. The mineral component consists of small single crystal grains of aragonite, the metastable orthorhombic polymorph of CaCO{sub 3}. The habit and morphology of the grains discussed here have not been determined previously. The observed habit and defect structure suggest that the organic matrix exerts a high degree of control over the crystal growth of the mineral phase and is responsible for the long range order in the microarhitecture. Electron beam heating of the mineral component leads to certain phase changes and these are discussed. 15 refs., 6 figs.

  10. Imaging electronic trap states in perovskite thin films with combined fluorescence and femtosecond transient absorption microscopy

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

    Xiao, Kai; Ma, Ying -Zhong; Simpson, Mary Jane; Doughty, Benjamin; Yang, Bin

    2016-04-22

    Charge carrier trapping degrades the performance of organometallic halide perovskite solar cells. To characterize the locations of electronic trap states in a heterogeneous photoactive layer, a spatially resolved approach is essential. Here, we report a comparative study on methylammonium lead tri-iodide perovskite thin films subject to different thermal annealing times using a combined photoluminescence (PL) and femtosecond transient absorption microscopy (TAM) approach to spatially map trap states. This approach coregisters the initially populated electronic excited states with the regions that recombine radiatively. Although the TAM images are relatively homogeneous for both samples, the corresponding PL images are highly structured. Themore » remarkable variation in the PL intensities as compared to transient absorption signal amplitude suggests spatially dependent PL quantum efficiency, indicative of trapping events. Furthermore, detailed analysis enables identification of two trapping regimes: a densely packed trapping region and a sparse trapping area that appear as unique spatial features in scaled PL maps.« less

  11. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

    SciTech Connect (OSTI)

    Woehl, Taylor J.; Kashyap, Sanjay; Firlar, Emre; Perez-Gonzalez, Teresa; Faivre, Damien; Trubitsyn, Denis; Bazylinski, Dennis A.; Prozorov, Tanya

    2014-10-31

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment. Here we present a correlative scanning TEM (STEM) and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid using an in situ fluid cell TEM holder. Fluorescently labeled cells were immobilized on microchip window surfaces and visualized in a fluid cell with STEM, followed by correlative fluorescence imaging to verify their membrane integrity. Notably, the post-STEM fluorescence imaging indicated that the bacterial cell wall membrane did not sustain radiation damage during STEM imaging at low electron dose conditions. We investigated the effects of radiation damage and sample preparation on the bacteria viability and found that approximately 50% of the bacterial membranes remained intact after an hour in the fluid cell, decreasing to ~30% after two hours. These results represent a first step toward in vivo studies of magnetite biomineralization in magnetotactic bacteria.

  12. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

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

    Woehl, Taylor J.; Kashyap, Sanjay; Firlar, Emre; Perez-Gonzalez, Teresa; Faivre, Damien; Trubitsyn, Denis; Bazylinski, Dennis A.; Prozorov, Tanya

    2014-10-31

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment. Here we present a correlative scanning TEM (STEM) and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid using an in situ fluid cell TEM holder. Fluorescently labeled cells were immobilized on microchip windowmore » surfaces and visualized in a fluid cell with STEM, followed by correlative fluorescence imaging to verify their membrane integrity. Notably, the post-STEM fluorescence imaging indicated that the bacterial cell wall membrane did not sustain radiation damage during STEM imaging at low electron dose conditions. We investigated the effects of radiation damage and sample preparation on the bacteria viability and found that approximately 50% of the bacterial membranes remained intact after an hour in the fluid cell, decreasing to ~30% after two hours. These results represent a first step toward in vivo studies of magnetite biomineralization in magnetotactic bacteria.« less

  13. 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)

    2015-01-01

    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 . 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.

  14. Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

    SciTech Connect (OSTI)

    Baranwal, R. and Burke, M.G.

    2003-03-03

    Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 {micro}m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large ({approx} 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation.

  15. Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid water

    SciTech Connect (OSTI)

    Proetto, Maria T.; Rush, Anthony M.; Chien, Miao-Ping; Abellan Baeza, Patricia; Patterson, Joseph P.; Thompson, Matthew P.; Olson, Norman H.; Moore, Curtis E.; Rheingold, Arnold L.; Andolina, Christopher; Millstone, Jill; Howell, Stephen B.; Browning, Nigel D.; Evans, James E.; Gianneschi, Nathan C.

    2014-01-14

    In this paper we present in situ transmission electron microscopy (TEM) of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterization of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerization of an oxaliplatin analog, designed for an ongoing program in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point toward key design parameters that enable this new characterization approach for organic nanomaterials. We describe the preparation of the synthetic micellar nanoparticles to- gether with their characterization in liquid water.

  16. Unraveling irradiation induced grain growth with in situ transmission electron microscopy and coordinated modeling

    SciTech Connect (OSTI)

    Bufford, D. C.; Abdeljawad, F. F.; Foiles, S. M.; Hattar, K.

    2015-11-09

    Nanostructuring has been proposed as a method to enhance radiation tolerance, but many metallic systems are rejected due to significant concerns regarding long term grain boundary and interface stability. This work utilized recent advancements in transmission electron microscopy (TEM) to quantitatively characterize the grain size, texture, and individual grain boundary character in a nanocrystalline gold model system before and after in situ TEM ion irradiation with 10 MeV Si. The initial experimental measurements were fed into a mesoscale phase field model, which incorporates the role of irradiation-induced thermal events on boundary properties, to directly compare the observed and simulated grain growth with varied parameters. The observed microstructure evolution deviated subtly from previously reported normal grain growth in which some boundaries remained essentially static. In broader terms, the combined experimental and modeling techniques presented herein provide future avenues to enhance quantification and prediction of the thermal, mechanical, or radiation stability of grain boundaries in nanostructured crystalline systems.

  17. An in situ electron microscopy technique for the study of thermally activated reactions in multilayered materials

    SciTech Connect (OSTI)

    Wall, M.A.; Barbee, T.W. Jr.; Weihs, T.P.

    1995-04-14

    A novel in situ transmission electron microscopy technique for the observation of reaction processes in multilayered materials is reported. The technique involves constant heating rate experiments of multilayered materials in image and diffraction modes. Because the fine scale microstructure of multilayered materials is typically a small fraction of the TEM specimen thickness, realistic comparison of the microstructural evolution with that of similarly processed thick foil samples is possible. Such experiments, when well designed, can provide rapid characterization of phase transformations and stability of nano-structured materials. The results of these experiments can be recorded in both video and micrograph format. The results and limitations of this technique will be shown for the Al/Zr and Al/Monel multilayered systems.

  18. Big Data and Deep data in scanning and electron microscopies: functionality from multidimensional data sets

    SciTech Connect (OSTI)

    Belianinov, Alex; Vasudevan, Rama K; Strelcov, Evgheni; Steed, Chad A; Yang, Sang Mo; Tselev, Alexander; Jesse, Stephen; Biegalski, Michael D; Shipman, Galen M; Symons, Christopher T; Borisevich, Albina Y; Archibald, Richard K; Kalinin, Sergei

    2015-01-01

    The development of electron, and scanning probe microscopies in the second half of the twentieth century have produced spectacular images of internal structure and composition of matter with, at nanometer, molecular, and atomic resolution. Largely, this progress was enabled by computer-assisted methods of microscope operation, data acquisition and analysis. The progress in imaging technologies in the beginning of the twenty first century has opened the proverbial floodgates of high-veracity information on structure and functionality. High resolution imaging now allows information on atomic positions with picometer precision, allowing for quantitative measurements of individual bond length and angles. Functional imaging often leads to multidimensional data sets containing partial or full information on properties of interest, acquired as a function of multiple parameters (time, temperature, or other external stimuli). Here, we review several recent applications of the big and deep data analysis methods to visualize, compress, and translate this data into physically and chemically relevant information from imaging data.

  19. High resolution electron microscopy study of as-prepared and annealed tungsten-carbon multilayers

    SciTech Connect (OSTI)

    Nguyen, T.D.; Gronsky, R.; Kortright, J.B.

    1988-12-01

    A series of sputtered tungsten-carbon multilayer structures with periods ranging from 2 to 12 nm in the as-prepared state and after annealing at 500/degree/C for 4 hours has been studied with high resolution transmission electron microscopy. The evolution with annealing of the microstructure of these multilayers depends on their period. As-prepared structures appear predominantly amorphous from TEM imaging and diffraction. Annealing results in crystallization of the W-rich layers into WC in the larger period samples, and less complete or no crystallization in the smaller period samples. X-ray scattering reveals that annealing expands the period in a systematic way. The layers remain remarkably well-defined after annealing under these conditions. 12 refs., 4 figs., 1 tab.

  20. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

    SciTech Connect (OSTI)

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.

  1. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

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

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; et al

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore » environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less

  2. Rendering graphene supports hydrophilic with non-covalent aromatic functionalization for transmission electron microscopy

    SciTech Connect (OSTI)

    Pantelic, Radosav S., E-mail: pantelic@imbb.forth.gr [National Cancer Institute, 50 South Drive, Building 50, Room 4306, Bethesda, Maryland 20892 (United States); Fu, Wangyang; Schoenenberger, Christian [Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056 (Switzerland); Stahlberg, Henning [Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, WRO-1058, Basel CH-4058 (Switzerland)

    2014-03-31

    Amorphous carbon films have been routinely used to enhance the preparation of frozen-hydrated samples for transmission electron microscopy (TEM), either in retaining protein concentration, providing mechanical stability or dissipating sample charge. However, strong background signal from the amorphous carbon support obstructs that of the sample, and the insulating properties of thin amorphous carbon films preclude any efficiency in dispersing charge. Graphene addresses the limitations of amorphous carbon. Graphene is a crystalline material with virtually no phase or amplitude contrast and unparalleled, high electrical carrier mobility. However, the hydrophobic properties of graphene have prevented its routine application in Cryo-TEM. This Letter reports a method for rendering graphene TEM supports hydrophilica convenient approach maintaining graphene's structural and electrical properties based on non-covalent, aromatic functionalization.

  3. Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy

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

    Leenheer, Andrew Jay; Jungjohann, Katherine Leigh; Zavadil, Kevin Robert; Sullivan, John P.; Harris, Charles Thomas

    2015-03-18

    Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating and stripping processes is needed to enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) to image the first few cycles of lithium electrodeposition/dissolution in liquid aprotic electrolyte at submicron resolution. Cycling at current densities from 1 to 25 mA/cm2 leads to variations in grain structure, with higher current densities giving a more needle-like, higher surface area deposit. The effectmore » of the electron beam was explored, and it was found that, even with minimal beam exposure, beam-induced surface film formation could alter the Li microstructure. The electrochemical dissolution was seen to initiate from isolated points on grains rather than uniformly across the Li surface, due to the stabilizing solid electrolyte interphase surface film. As a result, we discuss the implications for operando STEM liquid-cell imaging and Li-battery applications.« less

  4. Defects in paramagnetic Co-doped ZnO films studied by transmission electron microscopy

    SciTech Connect (OSTI)

    Kovcs, A.; Duchamp, M.; Boothroyd, C. B.; Dunin-Borkowski, R. E.; Ney, A.; Ney, V.; Galindo, P. L.; Kaspar, T. C.; Chambers, S. A.

    2013-12-28

    We study planar defects in epitaxial Co:ZnO dilute magnetic semiconductor thin films deposited on c-plane sapphire (Al{sub 2}O{sub 3}), as well as the Co:ZnO/Al{sub 2}O{sub 3} interface, using aberration-corrected transmission electron microscopy and electron energy-loss spectroscopy. Co:ZnO samples that were deposited using pulsed laser deposition and reactive magnetron sputtering are both found to contain extrinsic stacking faults, incoherent interface structures, and compositional variations within the first 34 Co:ZnO layers next to the Al{sub 2}O{sub 3} substrate. The stacking fault density is in the range of 10{sup 17} cm{sup ?3}. We also measure the local lattice distortions around the stacking faults. It is shown that despite the relatively high density of planar defects, lattice distortions, and small compositional variation, the Co:ZnO films retain paramagnetic properties.

  5. News Item

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

    Following the merge of the Molecular Foundry and the National Center for Electron Microscopy (NCEM) at the start of FY 2015, a new logo has been created to represent the newly ...

  6. Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)

    SciTech Connect (OSTI)

    Sato, Chikara; Manaka, Sachie; Nakane, Daisuke; Nishiyama, Hidetoshi; Suga, Mitsuo; Nishizaka, Takayuki; Miyata, Makoto; Maruyama, Yuusuke

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

  7. X-ray photoemission electron microscopy for the study of semiconductor materials

    SciTech Connect (OSTI)

    Anders, S.; Stammler, T.; Padmore, H.; Terminello, L.J.; Jankowski, A.F.; Stohr, J.; Diaz, J.; Cossy-Gantner, A.

    1998-03-01

    Photoemission Electron Microscopy (PEEM) using X-rays is a novel combination of two established materials analysis techniques--PEEM using UV light, and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. This combination allows the study of elemental composition and bonding structure of the sample by NEXAFS spectroscopy with a high spatial resolution given by the microscope. A simple, two lens, 10 kV operation voltage PEEM has been used at the Stanford Synchrotron Radiation Laboratory and at the Advanced Light Source (ALS) in Berkeley to study various problems including materials of interest for the semiconductor industry. In the present paper the authors give a short overview over the method and the instrument which was used, and describe in detail a number of applications. These applications include the study of the different phases of titanium disilicide, various phases of boron nitride, and the analysis of small particles. A brief outlook is given on possible new fields of application of the PEEM technique, and the development of new PEEM instruments.

  8. Scanning electron microscopy and x-ray photoelectron spectroscopy evaluation of MHD channel electrodes

    SciTech Connect (OSTI)

    Martello, D.V.; Baltrus, J.P.; Diehl, J.R.; Makovsky, L.E.

    1994-12-31

    Anode elements from the coal-fired Magnetohydrodynamic (MHD) channel at the Component Development and Integration Facility (CDIF) in Butte, Montana have been selected for study of the effects of localized phase morphology and chemistry on anode degradation. The platinum/tungsten/copper anode elements from the 1A{sub 4} channel were examined with scanning electron microscopy and X-ray photoelectron spectroscopy following testing in the MHD channel, and the results compared to those for unexposed anodes. Evidence suggests that the surface of the tungsten anode is chemically attacked by a potassium-rich slag to form a fine-grained crystalline reaction product layer that is covered by a fused, glassy slag during channel operation. Examination of a mechanically separated, partially delaminated platinum cap and polished cross-sections of anode segments showed evidence of chemical attack along the braze used to join the two caps. Interface porosity may provide a path for slag penetration and diffusion of corrosive gases and liquids during channel operation, leading to delamination. The microstructure of the brazed joint cross-sections were similar, independent of exposure severity in the MHD channel. The primary mechanism of tungsten degradation appears to be grain exfoliation due to severe grain boundary attack.

  9. Applications of scanning electron microscopy to the study of mineral matter in peat

    SciTech Connect (OSTI)

    Raymond, R. Jr.; Andrejko, M.J.; Bardin, S.W.

    1983-01-01

    Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) have been used for in situ analysis of minerals in peats by combining methods for producing oriented microtome sections of peat with methods for critical point drying. The combined technique allows SEM analysis of the inorganic components and their associated botanical constituents, along with petrographic identification of the botanical constituents. In peat deposits with abundant fluvial- or marine-derived minerals, one may use the above technique and/or medium- or low-temperature ashing followed by x-ray diffraction to readily identify the various mineral components. However, in some freshwater environments the scarcity of non-silica minerals makes the above techniques impractical. By separating the inorganic residues from the peat, one can isolate the non-silica mineral matter in the SEM for analysis by EDS. Furthermore, such separation allows SEM analysis of features and textures of both silica and non-silica mineral particles that might otherwise be unidentifiable. Results indicate the occurrence of detritial minerals in both Okefenokee and Snuggedy Swamp peats, the presence of authigenic or diagenetic minerals growing within peats, and dissolution features on freshwater sponge spicules that may account for the absence of spicules in Tertiary lignites.

  10. Thermodynamic Prediction of Compositional Phases Confirmed by Transmission Electron Microscopy on Tantalum-Based Alloy Weldments

    SciTech Connect (OSTI)

    Moddeman, William E.; Birkbeck, Janine C.; Barklay, Chadwick D.; Kramer, Daniel P.; Miller, Roger G.; Allard, Lawrence F.

    2007-01-30

    Tantalum alloys have been used by the U.S. Department of Energy as structural alloys for radioisotope based thermal to electrical power systems since the 1960s. Tantalum alloys are attractive for high temperature structural applications due to their high melting point, excellent formability, good thermal conductivity, good ductility (even at low temperatures), corrosion resistance, and weldability. Tantalum alloys have demonstrated sufficient high-temperature toughness to survive prolonged exposure to the radioisotope power-system working environment. Typically, the fabrication of power systems requires the welding of various components including the structural members made of tantalum alloys. Issues such as thermodynamics, lattice structure, weld pool dynamics, material purity and contamination, and welding atmosphere purity all potentially confound the understanding of the differences between the weldment properties of the different tantalum-based alloys. The objective of this paper is to outline the thermodynamically favorable material phases in tantalum alloys, with and without small amounts of hafnium, during and following solidification, based on the results derived from the FactSage(c) Integrated Thermodynamic Databank. In addition, Transition Electron Microscopy (TEM) data will show for the first time, the changes occurring in the HfC before and after welding, and the data will elucidate the role HfC plays in pinning grain boundaries.

  11. X-ray structure determination using low-resolution electron microscopy maps for molecular replacement

    SciTech Connect (OSTI)

    Jackson, Ryan N.; McCoy, Airlie J.; Terwilliger, Thomas C.; Read, Randy J.; Wiedenheft, Blake

    2015-07-30

    Structures of multi-subunit macromolecular machines are primarily determined by either electron microscopy (EM) or X-ray crystallography. In many cases, a structure for a complex can be obtained at low resolution (at a coarse level of detail) with EM and at higher resolution (with finer detail) by X-ray crystallography. The integration of these two structural techniques is becoming increasingly important for generating atomic models of macromolecular complexes. A low-resolution EM image can be a powerful tool for obtaining the "phase" information that is missing from an X-ray crystallography experiment, however integration of EM and X-ray diffraction data has been technically challenging. Here we show a step-by-step protocol that explains how low-resolution EM maps can be placed in the crystallographic unit cell by molecular replacement, and how initial phases computed from the placed EM density are extended to high resolution by averaging maps over non-crystallographic symmetry. As the resolution gap between EM and Xray crystallography continues to narrow, the use of EM maps to help with X-ray crystal structure determination, as described in this protocol, will become increasingly effective.

  12. X-ray structure determination using low-resolution electron microscopy maps for molecular replacement

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

    Jackson, Ryan N.; McCoy, Airlie J.; Terwilliger, Thomas C.; Read, Randy J.; Wiedenheft, Blake

    2015-07-30

    Structures of multi-subunit macromolecular machines are primarily determined by either electron microscopy (EM) or X-ray crystallography. In many cases, a structure for a complex can be obtained at low resolution (at a coarse level of detail) with EM and at higher resolution (with finer detail) by X-ray crystallography. The integration of these two structural techniques is becoming increasingly important for generating atomic models of macromolecular complexes. A low-resolution EM image can be a powerful tool for obtaining the "phase" information that is missing from an X-ray crystallography experiment, however integration of EM and X-ray diffraction data has been technically challenging.more » Here we show a step-by-step protocol that explains how low-resolution EM maps can be placed in the crystallographic unit cell by molecular replacement, and how initial phases computed from the placed EM density are extended to high resolution by averaging maps over non-crystallographic symmetry. As the resolution gap between EM and Xray crystallography continues to narrow, the use of EM maps to help with X-ray crystal structure determination, as described in this protocol, will become increasingly effective.« less

  13. Characterization of plutonium-bearing wastes by chemical analysis and analytical electron microscopy

    SciTech Connect (OSTI)

    Behrens, R.G.; Buck, E.C.; Dietz, N.L.; Bates, J.K.; Van Deventer, E.; Chaiko, D.J.

    1995-09-01

    This report summarizes the results of characterization studies of plutonium-bearing wastes produced at the US Department of Energy weapons production facilities. Several different solid wastes were characterized, including incinerator ash and ash heels from Rocky Flats Plant and Los Alamos National Laboratory; sand, stag, and crucible waste from Hanford; and LECO crucibles from the Savannah River Site. These materials were characterized by chemical analysis and analytical electron microscopy. The results showed the presence of discrete PuO{sub 2}PuO{sub 2{minus}x}, and Pu{sub 4}O{sub 7} phases, of about 1{mu}m or less in size, in all of the samples examined. In addition, a number of amorphous phases were present that contained plutonium. In all the ash and ash heel samples examined, plutonium phases were found that were completely surrounded by silicate matrices. Consequently, to achieve optimum plutonium recovery in any chemical extraction process, extraction would have to be coupled with ultrafine grinding to average particle sizes of less than 1 {mu}m to liberate the plutonium from the surrounding inert matrix.

  14. Big Data and Deep data in scanning and electron microscopies: functionality from multidimensional data sets

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

    Belianinov, Alex; Vasudevan, Rama K; Strelcov, Evgheni; Steed, Chad A; Yang, Sang Mo; Tselev, Alexander; Jesse, Stephen; Biegalski, Michael D; Shipman, Galen M; Symons, Christopher T; et al

    2015-01-01

    The development of electron, and scanning probe microscopies in the second half of the twentieth century have produced spectacular images of internal structure and composition of matter with, at nanometer, molecular, and atomic resolution. Largely, this progress was enabled by computer-assisted methods of microscope operation, data acquisition and analysis. The progress in imaging technologies in the beginning of the twenty first century has opened the proverbial floodgates of high-veracity information on structure and functionality. High resolution imaging now allows information on atomic positions with picometer precision, allowing for quantitative measurements of individual bond length and angles. Functional imaging often leadsmore » to multidimensional data sets containing partial or full information on properties of interest, acquired as a function of multiple parameters (time, temperature, or other external stimuli). Here, we review several recent applications of the big and deep data analysis methods to visualize, compress, and translate this data into physically and chemically relevant information from imaging data.« less

  15. High resolution transmission electron microscopy of melamine-formaldehyde aerogels and silica aerogels

    SciTech Connect (OSTI)

    Ruben, G.C. (Dartmouth Coll., Hanover, NH (United States). Dept. of Biological Sciences)

    1991-09-01

    The goal of the high resolution transmission electron microscopy (HRTEM) was to image the structure of two tetramethyl orthosilicate (TMOS) and two melamine-formaldehyde (MF) aerogels at the single polymer chain level{sup 1,2}. With this level of structural resolution we hoped to interrelate each aerogel's structure with its physical properties and its method of synthesis. Conventional single-step base catalysed TMOS aerogels show strings of spheroidal particles linked together with minimal necking. The spheroidal particles range from 86--132 {Angstrom} and average 113{plus minus}10 {Angstrom} in diameter{sup 2}. In contrast the TMOS aerogels reported on here were made by a two step method. After extended silica chains are grown in solution under acidic conditions with a substoichiometric amount of water, the reaction is stopped and the methanol hydrolysed from TMOS is removed. Then base catalysis and additional water are added to cause gel formation is a nonalcoholic solvent. The MF aerogels were prepared for HRTEM by fracturing them on a stereo microscope stage with razor knife so that fractured pieces with smooth flat surfaces could be selected for platinum-carbon replication. The two silica (TMOS) aerogels were both transparent and difficult to see. These aerogels were fractured on a stereo microscope stage with tweezers. 6 refs., 4 figs.

  16. Detecting Cellulase Penetration Into Corn Stover Cell Walls by Immuno-Electron Microscopy

    SciTech Connect (OSTI)

    Donohoe, B. S.; Selig, M. J.; Viamajala, S.; Vinzant, T. B.; Adney, W. S.; Himmel, M. E.

    2009-06-15

    In general, pretreatments are designed to enhance the accessibility of cellulose to enzymes, allowing for more efficient conversion. In this study, we have detected the penetration of major cellulases present in a commercial enzyme preparation (Spezyme CP) into corn stem cell walls following mild-, moderate- and high-severity dilute sulfuric acid pretreatments. The Trichoderma reesei enzymes, Cel7A (CBH I) and Cel7B (EG I), as well as the cell wall matrix components xylan and lignin were visualized within digested corn stover cell walls by immuno transmission electron microscopy (TEM) using enzyme- and polymer-specific antibodies. Low severity dilute-acid pretreatment (20 min at 100 C) enabled <1% of the thickness of secondary cell walls to be penetrated by enzyme, moderate severity pretreatment at (20 min at 120 C) allowed the enzymes to penetrate {approx}20% of the cell wall, and the high severity (20 min pretreatment at 150 C) allowed 100% penetration of even the thickest cell walls. These data allow direct visualization of the dramatic effect dilute-acid pretreatment has on altering the condensed ultrastructure of biomass cell walls. Loosening of plant cell wall structure due to pretreatment and the subsequently improved access by cellulases has been hypothesized by the biomass conversion community for over two decades, and for the first time, this study provides direct visual evidence to verify this hypothesis. Further, the high-resolution enzyme penetration studies presented here provide insight into the mechanisms of cell wall deconstruction by cellulolytic enzymes.

  17. Impact of membrane-induced particle immobilization on seeded growth monitored by in situ liquid scanning transmission electron microscopy

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

    Weiner, Rebecca G.; Chen, Dennis P.; Unocic, Raymond R.; Skrabalak, Sara E.

    2016-04-01

    In situ liquid cell scanning transmission electron microscopy probes seeded growth in real time. The growth of Pd on Au nanocubes is monitored as a model system to compare growth within a liquid cell and traditional colloidal synthesis. Furthermore, different growth patterns are observed due to seed immobilization and the highly reducing environment within the liquid cell.

  18. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    SciTech Connect (OSTI)

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

  19. Non parametric denoising methods based on wavelets: Application to electron microscopy images in low exposure time

    SciTech Connect (OSTI)

    Soumia, Sid Ahmed; Messali, Zoubeida; Ouahabi, Abdeldjalil; Trepout, Sylvain E-mail: cedric.messaoudi@curie.fr Messaoudi, Cedric E-mail: cedric.messaoudi@curie.fr Marco, Sergio E-mail: cedric.messaoudi@curie.fr

    2015-01-13

    The 3D reconstruction of the Cryo-Transmission Electron Microscopy (Cryo-TEM) and Energy Filtering TEM images (EFTEM) hampered by the noisy nature of these images, so that their alignment becomes so difficult. This noise refers to the collision between the frozen hydrated biological samples and the electrons beam, where the specimen is exposed to the radiation with a high exposure time. This sensitivity to the electrons beam led specialists to obtain the specimen projection images at very low exposure time, which resulting the emergence of a new problem, an extremely low signal-to-noise ratio (SNR). This paper investigates the problem of TEM images denoising when they are acquired at very low exposure time. So, our main objective is to enhance the quality of TEM images to improve the alignment process which will in turn improve the three dimensional tomography reconstructions. We have done multiple tests on special TEM images acquired at different exposure time 0.5s, 0.2s, 0.1s and 1s (i.e. with different values of SNR)) and equipped by Golding beads for helping us in the assessment step. We herein, propose a structure to combine multiple noisy copies of the TEM images. The structure is based on four different denoising methods, to combine the multiple noisy TEM images copies. Namely, the four different methods are Soft, the Hard as Wavelet-Thresholding methods, Bilateral Filter as a non-linear technique able to maintain the edges neatly, and the Bayesian approach in the wavelet domain, in which context modeling is used to estimate the parameter for each coefficient. To ensure getting a high signal-to-noise ratio, we have guaranteed that we are using the appropriate wavelet family at the appropriate level. So we have chosen âĂIJsym8âĂİ wavelet at level 3 as the most appropriate parameter. Whereas, for the bilateral filtering many tests are done in order to determine the proper filter parameters represented by the size of the filter, the range parameter and the

  20. SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES

    SciTech Connect (OSTI)

    Hay, M.; O'Rourke, P.; Ajo, H.

    2012-03-08

    The F-Area Tank Farm (FTF) Performance Assessment (PA) utilizes waste speciation in the waste release model used in the FTF fate and transport modeling. The waste release modeling associated with the residual plutonium in Tank 18 has been identified as a primary contributor to the Tank 18 dose uncertainty. In order to reduce the uncertainty related to plutonium in Tank 18, a better understanding of the plutonium speciation in the Tank 18 waste (including the oxidation state and stoichiometry) is desired. Savannah River National Laboratory (SRNL) utilized Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to analyze Tank 18 samples to provide information on the speciation of plutonium in the waste material. XRD analysis of the Tank 18 samples did not identify any plutonium mineral phases in the samples. These indicates the crystalline mineral phases of plutonium are below the detection limits of the XRD method or that the plutonium phase(s) lack long range order and are present as amorphous or microcrystalline solids. SEM analysis of the Tank 18 samples did locate particles containing plutonium. The plutonium was found as small particles, usually <1 {micro}m but ranging up to several micrometers in diameter, associated with particles of an iron matrix and at low concentration in other elemental matrices. This suggests the plutonium has an affinity for the iron matrix. Qualitatively, the particles of plutonium found in the SEM analysis do not appear to account for all of the plutonium in the sample based on concentrations determined from the chemical analysis of the Tank 18 samples. This suggests that plutonium is also distributed throughout the solids in low concentrations.

  1. Structural evolution and strain induced mixing in Cu–Co composites studied by transmission electron microscopy and atom probe tomography

    SciTech Connect (OSTI)

    Bachmaier, A.; Aboulfadl, H.; Pfaff, M.; Mücklich, F.; Motz, C.

    2015-02-15

    A Cu–Co composite material is chosen as a model system to study structural evolution and phase formations during severe plastic deformation. The evolving microstructures as a function of the applied strain were characterized at the micro-, nano-, and atomic scale-levels by combining scanning electron microscopy and transmission electron microscopy including energy-filtered transmission electron microscopy and electron energy-loss spectroscopy. The amount of intermixing between the two phases at different strains was examined at the atomic scale using atom probe tomography as complimentary method. It is shown that Co particles are dissolved in the Cu matrix during severe plastic deformation to a remarkable extent and their size, number, and volume fraction were quantitatively determined during the deformation process. From the results, it can be concluded that supersaturated solid solutions up to 26 at.% Co in a fcc Cu–26 at.% Co alloy are obtained during deformation. However, the distribution of Co was found to be inhomogeneous even at the highest degree of investigated strain. - Highlights: • Structural evolution in a deformed Cu–Co composite is studied on all length scales. • Amount of intermixing is examined by atom-probe tomography. • Supersaturated solid solutions up to 26 at.% Co in Cu are observed.

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

    SciTech Connect (OSTI)

    Chatterjee, Vijay; Harniman, Robert; May, Paul W.; Barhai, P. K.

    2014-04-28

    The emission of electrons from diamond in vacuum occurs readily as a result of the negative electron affinity of the hydrogenated surface due to features with nanoscale dimensions, which can concentrate electric fields high enough to induce electron emission from them. Electrons can be emitted as a result of an applied electric field (field emission) with possible uses in displays or cold-cathode devices. Alternatively, electrons can be emitted simply by heating the diamond in vacuum to temperatures as low as 350?C (thermionic emission), and this may find applications in solar energy generation or energy harvesting devices. Electron emission studies usually use doped polycrystalline diamond films deposited onto Si or metallic substrates by chemical vapor deposition, and these films have a rough, faceted morphology on the micron or nanometer scale. Electron emission is often improved by patterning the diamond surface into sharp points or needles, the idea being that the field lines concentrate at the points lowering the barrier for electron emission. However, there is little direct evidence that electrons are emitted from these sharp tips. The few reports in the literature that have studied the emission sites suggested that emission came from the grain boundaries and not the protruding regions. We now present direct observation of the emission sites over a large area of polycrystalline diamond using tunneling atomic force microscopy. We confirm that the emission current comes mostly from the grain boundaries, which is consistent with a model for emission in which the non-diamond phase is the source of electrons with a threshold that is determined by the surrounding hydrogenated diamond surface.

  3. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  4. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e⁻aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e⁻aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore » deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e⁻aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e⁻aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less

  5. Time dependent changes in Schottky barrier mapping of the W/Si(001) interface utilizing ballistic electron emission microscopy

    SciTech Connect (OSTI)

    Durcan, Chris A.; Balsano, Robert; LaBella, Vincent P.

    2015-06-28

    The W/Si(001) Schottky barrier height is mapped to nanoscale dimensions using ballistic electron emission microscopy (BEEM) over a period of 21 days to observe changes in the interface electrostatics. Initially, the average spectrum is fit to a Schottky barrier height of 0.71 eV, and the map is uniform with 98% of the spectra able to be fit. After 21 days, the average spectrum is fit to a Schottky barrier height of 0.62 eV, and the spatial map changes dramatically with only 27% of the spectra able to be fit. Transmission electron microscopy shows the formation of an ultra-thin tungsten silicide at the interface, which increases in thickness over the 21 days. This increase is attributed to an increase in electron scattering and the changes are observed in the BEEM measurements. Interestingly, little to no change is observed in the I-V measurements throughout the 21 day period.

  6. Largely defocused probe scanning transmission electron microscopy for imaging local modulation of strain field in a hetero interface

    SciTech Connect (OSTI)

    Kim, Suhyun Jung, Younheum; Kim, Joong Jung; Lee, Sunyoung; Lee, Haebum; Oshima, Yoshifumi

    2014-10-13

    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.

  7. Determination of pigments in colour layers on walls of some selected historical buildings using optical and scanning electron microscopy

    SciTech Connect (OSTI)

    Skapin, A. Sever Ropret, P. Bukovec, P.

    2007-11-15

    For successful restoration of painted walls and painted coloured finishing coats it is necessary to determine the composition of the original colour layers. Identification of the pigments used in The Cistercian Abbey of Sticna and The Manor of Novo Celje was carried out using optical and scanning electron microscopy. Selected samples of wall paintings were inspected by the combined application of an optical microscope and a low-vacuum Scanning Electron Microscope to determine their colour and structural features and to identify the position of individual pigment grains. Energy dispersive spectroscopy was used to determine the elemental distribution on selected surfaces and elemental composition of individual pigments. It was found that the most abundantly used pigments were iron oxide red, cinnabar, green earth, umber, calcium carbonate white, ultramarine, yellow ochre and carbon black. These identifications have allowed us to compare the use of various pigments in buildings from different historical periods.

  8. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

    SciTech Connect (OSTI)

    Santala, M. K. Campbell, G. H.; Raoux, S.

    2015-12-21

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ∼100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measured with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. The high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.

  9. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

    SciTech Connect (OSTI)

    Santala, M. K.; Raoux, S.; Campbell, G. H.

    2015-12-24

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ~100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measured with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. As a result, the high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.

  10. Magnetic properties and transmission electron microscopy studies of Ni nanoparticles encapsulated in carbon nanocages and carbon nanotubes

    SciTech Connect (OSTI)

    He Chunnian; Zhao Naiqin Shi Chunsheng; Li Jiajun; Li Haipeng

    2008-08-04

    Three types of carbon nanomaterials, including bamboo-shaped carbon nanotubes with Ni encapsulated and hollow and Ni catalytic particles filled carbon nanocages, have been prepared by methane catalytic decomposition at a relatively low temperature. Transmission electron microscopy observations showed that fascinating fullerene-like Ni-C (graphitic) core-shell nanostructures predominated. Detailed examination of high-resolution transmission electron microscopy showed that the walls of bamboo-shaped carbon nanotubes with quasi-cone catalytic particles encapsulated consisted of oblique graphene planes with respect to the tube axis. The Ni particles encapsulated in the carbon nanocages were larger than that encapsulated in carbon nanotubes, but the diameters of the cores of hollow carbon nanocages were less than that of Ni particles encapsulated in carbon nanotubes, suggesting that the sizes of catalyst particles played an important role during carbon nanomaterial growth. The magnetic properties of the carbon nanomaterials were measured, which showed relatively large coercive force (H{sub c} = 138.4 O{sub e}) and good ferromagnetism (M{sub r}/M{sub s} = 0.325)

  11. Electron-Impact Water-Jet Microfocus Source for Water-Window Microscopy

    SciTech Connect (OSTI)

    Skoglund, P.; Lundstroem, U.; Vogt, U.; Takman, P.; Hertz, H. M.

    2011-09-09

    We demonstrate high-brightness operation of an electron-impact water-jet-anode soft x-ray source with an increased power loading of 15 times compared to our previously published results, with a corresponding increase in {approx}525-eV x-ray intensity of 6.4 times. This has been accomplished by improving the vacuum pumping system and the electron focusing optics, and increasing the liquid-jet velocity. The source now operates up to 120-W e-beam power and at a 525-eV brightness of 3.5x10{sup 9} ph/(sx{mu}m{sup 2}xsrxline). The source concept has potential to increase the x-ray brightness by another order of magnitude by optimizing the e-beam focusing and upgrading the power supply. Currently, spot enlargement with increased power is determined to be the most important limiting factor.

  12. Gas mixing system for imaging of nanomaterials under dynamic environments by environmental transmission electron microscopy

    SciTech Connect (OSTI)

    Akatay, M. Cem; Zvinevich, Yury; Ribeiro, Fabio H. E-mail: estach@bnl.gov; Baumann, Philipp; Stach, Eric A. E-mail: estach@bnl.gov

    2014-03-15

    A gas mixing manifold system that is capable of delivering a stable pressure stream of a desired composition of gases into an environmental transmission electron microscope has been developed. The system is designed to provide a stable imaging environment upon changes of either the composition of the gas mixture or upon switching from one gas to another. The design of the system is described and the response of the pressure inside the microscope, the sample temperature, and sample drift in response to flow and composition changes of the system are reported.

  13. Schottky barrier height measurements of Cu/Si(001), Ag/Si(001), and Au/Si(001) interfaces utilizing ballistic electron emission microscopy and ballistic hole emission microscopy

    SciTech Connect (OSTI)

    Balsano, Robert; Matsubayashi, Akitomo; LaBella, Vincent P.

    2013-11-15

    The Schottky barrier heights of both n and p doped Cu/Si(001), Ag/Si(001), and Au/Si(001) diodes were measured using ballistic electron emission microscopy and ballistic hole emission microscopy (BHEM), respectively. Measurements using both forward and reverse ballistic electron emission microscopy (BEEM) and (BHEM) injection conditions were performed. The Schottky barrier heights were found by fitting to a linearization of the power law form of the Bell-Kaiser BEEM model. The sum of the n-type and p-type barrier heights are in good agreement with the band gap of silicon and independent of the metal utilized. The Schottky barrier heights are found to be below the region of best fit for the power law form of the BK model, demonstrating its region of validity.

  14. An efficient and cost-effective method for preparing transmission electron microscopy samples from powders

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

    Wen, Haiming; Lin, Yaojun; Seidman, David N.; Schoenung, Julie M.; van Rooyen, Isabella J.; Lavernia, Enrique J.

    2015-09-09

    The preparation of transmission electron microcopy (TEM) samples from powders with particle sizes larger than ~100 nm poses a challenge. The existing methods are complicated and expensive, or have a low probability of success. Herein, we report a modified methodology for preparation of TEM samples from powders, which is efficient, cost-effective, and easy to perform. This method involves mixing powders with an epoxy on a piece of weighing paper, curing the powder–epoxy mixture to form a bulk material, grinding the bulk to obtain a thin foil, punching TEM discs from the foil, dimpling the discs, and ion milling the dimpledmore » discs to electron transparency. Compared with the well established and robust grinding–dimpling–ion-milling method for TEM sample preparation for bulk materials, our modified approach for preparing TEM samples from powders only requires two additional simple steps. In this article, step-by-step procedures for our methodology are described in detail, and important strategies to ensure success are elucidated. Furthermore, our methodology has been applied successfully for preparing TEM samples with large thin areas and high quality for many different mechanically milled metallic powders.« less

  15. Ultrahigh-spatial-resolution chemical and magnetic imaging by laser-based photoemission electron microscopy

    SciTech Connect (OSTI)

    Taniuchi, Toshiyuki Kotani, Yoshinori; Shin, Shik

    2015-02-15

    We report the first experiments carried out on a new chemical and magnetic imaging system, which combines the high spatial resolution of a photoemission electron microscope (PEEM) with a continuous-wave deep-ultraviolet laser. Threshold photoemission is sensitive to the chemical and magnetic structures of the surface of materials. The spatial resolution of PEEM is limited by space charging when using pulsed photon sources as well as aberrations in the electron optics. We show that the use of a continuous-wave laser enabled us to overcome such a limit by suppressing the space-charge effect, allowing us to obtain a resolution of approximately 2.6 nm. With this system, we demonstrated the imaging of surface reconstruction domains on Si(001) by linear dichroism with normal incidence of the laser beam. We also succeeded in magnetic imaging of thin films with the use of magnetic circular dichroism near the Fermi level. The unique features of the ultraviolet laser will give us fast switching of the incident angles and polarizations of the photon source, which will be useful for the characterization of antiferromagnetic materials as well as ferromagnetic materials.

  16. Comparison of SOFC Cathode Microstructure Quantified using X-ray Nanotomography and Focused Ioni Beam-scanning Electron Microscopy

    SciTech Connect (OSTI)

    G Nelson; W Harris; J Lombardo; J Izzo Jr.; W Chiu; P Tanasini; M Cantoni; J Van herle; C Comninellis; et al.

    2011-12-31

    X-ray nanotomography and focused ion beam scanning electron microscopy (FIB-SEM) have been applied to investigate the complex 3D microstructure of solid oxide fuel cell (SOFC) electrodes at spatial resolutions of 45 nm and below. The application of near edge differential absorption for x-ray nanotomography and energy selected backscatter detection for FIB-SEM enable elemental mapping within the microstructure. Using these methods, non-destructive 3D x-ray imaging and FIB-SEM serial sectioning have been applied to compare three-dimensional elemental mapping of the LSM, YSZ, and pore phases in the SOFC cathode microstructure. The microstructural characterization of an SOFC cathode is reported based on these measurements. The results presented demonstrate the viability of x-ray nanotomography as a quantitative characterization technique and provide key insights into the SOFC cathode microstructure.

  17. Comparison of SOFC Cathode Microstructure Quantified using X-ray Nanotomography and Focused Ion Beam - Scanning Electron Microscopy

    SciTech Connect (OSTI)

    Nelson, George J.; Harris, William H.; Lombardo, Jeffrey J.; Izzo, Jr., John R.; Chiu, W. K. S.; Tanasini, Pietro; Cantoni, Marco; Van herle, Jan; Comninellis, Christos; Andrews, Joy C.; Liu, Yijin; Pianetta, Piero; Chu, Yong

    2011-03-24

    X-ray nanotomography and focused ion beam scanning electron microscopy (FIB-SEM) have been applied to investigate the complex 3D microstructure of solid oxide fuel cell (SOFC) electrodes at spatial resolutions of 45 nm and below. The application of near edge differential absorption for x-ray nanotomography and energy selected backscatter detection for FIBSEM enable elemental mapping within the microstructure. Using these methods, non-destructive 3D x-ray imaging and FIBSEM serial sectioning have been applied to compare three-dimensional elemental mapping of the LSM, YSZ, and pore phases in the SOFC cathode microstructure. The microstructural characterization of an SOFC cathode is reported based on these measurements. The results presented demonstrate the viability of x-ray nanotomography as a quantitative characterization technique and provide key insights into the SOFC cathode microstructure.

  18. Real-time observation of morphological transformations in II-VI semiconducting nanobelts via environmental transmission electron microscopy

    SciTech Connect (OSTI)

    Agarwal, Rahul; Zakharov, Dmitri N.; Krook, Nadia M.; Liu, Wenjing; Berger, Jacob; Stach, Eric A.; Agarwal, Ritesh

    2015-05-01

    It has been observed that wurtzite II–VI semiconducting nanobelts transform into single-crystal, periodically branched nanostructures upon heating. The mechanism of this novel transformation has been elucidated by heating II–VI nanobelts in an environmental transmission electron microscope (ETEM) in oxidizing, reducing and inert atmospheres while observing their structural changes with high spatial resolution. The interplay of surface reconstruction of high-energy surfaces of the wurtzite phase and environment-dependent anisotropic chemical etching of certain crystal surfaces in the branching mechanism of nanobelts has been observed. Understanding of structural and chemical transformations of materials via in situ microscopy techniques and their role in designing new nanostructured materials is discussed.

  19. High-resolution transmission electron microscopy study of carbon deposited on the NiO/MgO solid solution catalysts

    SciTech Connect (OSTI)

    Hu, Y.H.; Ruckenstein, E.

    1999-05-15

    The carbon deposition due to the CH{sub 4} decomposition at 790 C over NiO/MgO catalysts was investigated by high-resolution transmission electron microscopy. While no deposits could be detected over the catalysts with a NiO content smaller than 9.1 wt%, they were detected over the catalysts with NiO contents of 23 and 50 wt%. The carbon deposits are composed of platelets located at distances of about 0.34 nm, corresponding to the graphitic carbon. Various structures of the deposited carbon were observed: (a) carbon consisting of platelets parallel to the surface of the particle, which covers a catalyst particle, (b) nanotubes composed of platelets parallel to their axis, and (c) carbon vortexes consisting of platelets parallel to their axis.

  20. Hot-stage transmission electron microscopy study of (Na, K)NbO{sub 3} based lead-free piezoceramics

    SciTech Connect (OSTI)

    Lu, Shengbo; Xu, Zhengkui; Kwok, K. W.; Chan, Helen L. W.

    2014-07-28

    Hierarchical nanodomains assembled into micron-sized stripe domains, which is believed to be associated with outstanding piezoelectric properties, were observed at room temperature in a typical lead free piezoceramics, (Na{sub 0.52}K{sub 0.48−x})(Nb{sub 0.95−x}Ta{sub 0.05})-xLiSbO{sub 3}, with finely tuned polymorphic phase boundaries (x = 0.0465) by transmission electron microscopy. The evolution of domain morphology and crystal structure under heating and cooling cycles in the ceramic was investigated by in-situ hot stage study. It is found that the nanodomains are irreversibly transformed into micron-sized rectangular domains during heating and cooling cycles, which lead to the thermal instability of piezoelectric properties of the materials.

  1. Direct Visualization of Solid Electrolyte Interphase Formation in Lithium-Ion Batteries with In Situ Electrochemical Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Unocic, Raymond R; Sun, Xiao-Guang; Sacci, Robert L; Adamczyk, Leslie A; Alsem, Daan Hein; Dai, Sheng; Dudney, Nancy J; More, Karren Leslie

    2014-01-01

    Complex, electrochemically driven transport processes form the basis of electrochemical energy storage devices. The direct imaging of electrochemical processes at high spatial resolution and within their native liquid electrolyte would significantly enhance our understanding of device functionality, but has remained elusive. In this work we use a recently developed liquid cell for in situ electrochemical transmission electron microscopy to obtain insight into the electrolyte decomposition mechanisms and kinetics in lithium-ion (Li-ion) batteries by characterizing the dynamics of solid electrolyte interphase (SEI) formation and evolution. Here we are able to visualize the detailed structure of the SEI that forms locally at the electrode/electrolyte interface during lithium intercalation into natural graphite from an organic Li-ion battery electrolyte. We quantify the SEI growth kinetics and observe the dynamic self-healing nature of the SEI with changes in cell potential.

  2. Real-time observation of morphological transformations in II-VI semiconducting nanobelts via environmental transmission electron microscopy

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

    Agarwal, Rahul; Zakharov, Dmitri N.; Krook, Nadia M.; Liu, Wenjing; Berger, Jacob; Stach, Eric A.; Agarwal, Ritesh

    2015-05-01

    It has been observed that wurtzite II–VI semiconducting nanobelts transform into single-crystal, periodically branched nanostructures upon heating. The mechanism of this novel transformation has been elucidated by heating II–VI nanobelts in an environmental transmission electron microscope (ETEM) in oxidizing, reducing and inert atmospheres while observing their structural changes with high spatial resolution. The interplay of surface reconstruction of high-energy surfaces of the wurtzite phase and environment-dependent anisotropic chemical etching of certain crystal surfaces in the branching mechanism of nanobelts has been observed. Understanding of structural and chemical transformations of materials via in situ microscopy techniques and their role in designingmore » new nanostructured materials is discussed.« less

  3. 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.; Dekker, A. J. den; Rosenauer, A.; Sijbers, J.

    2014-08-11

    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.

  4. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

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

    Santala, M. K.; Raoux, S.; Campbell, G. H.

    2015-12-24

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ~100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measuredmore » with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. As a result, the high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.« less

  5. Investigation of Mineral Transformations in Wet Supercritical CO2 by Electron Microscopy

    SciTech Connect (OSTI)

    Arey, Bruce W.; Kovarik, Libor; Wang, Zheming; Felmy, Andrew R.

    2011-10-10

    The capture and storage of carbon dioxide and other greenhouse gases in deep geologic formations represents one of the most promising options for mitigating the impacts of greenhouse gases on global warming. In this regard, mineral-fluid interactions are of prime importance since such reactions can result in the long term sequestration of CO2 by trapping in mineral phases. Recently it has been recognized that interactions with neat to water-saturated non-aqueous fluids are of prime importance in understanding mineralization reactions since the introduced CO2 is likely to contain water initially or soon after injection and the supercritical CO2 (scCO2) is less dense than the aqueous phase which can result in a buoyant scCO2 plume contacting the isolating caprock. As a result, unraveling the molecular/microscopic mechanisms of mineral transformation in neat to water saturated scCO2 has taken on an added important. In this study, we are examining the interfacial reactions of the olivine mineral forsterite (Mg2SiO4) over a range of water contents up to and including complete water saturation in scCO2. The surface precipitates that form on the reacted forsterite grains are extremely fragile and difficult to experimentally characterize. In order to address this issue we have developed experimental protocols for preparing and imaging electron-transparent samples from fragile structures. These electron-transparent samples are then examined using a combination of STEM/EDX, FIB-TEM, and helium ion microscope (HIM) imaging (Figures 1-3). This combination of capabilities has provided unique insight into the geochemical processes that occur on scCO2 reacted mineral surfaces. The experimental procedures and protocols that have been developed also have useful applications for examining fragile structures on a wide variety of materials. This research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and

  6. Probing the Degradation Mechanisms in Electrolyte Solutions for Li-ion Batteries by In-Situ Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Abellan Baeza, Patricia; Mehdi, Beata L.; Parent, Lucas R.; Gu, Meng; Park, Chiwoo; Xu, Wu; Zhang, Yaohui; Arslan, Ilke; Zhang, Jiguang; Wang, Chong M.; Evans, James E.; Browning, Nigel D.

    2014-02-21

    One of the goals in the development of new battery technologies is to find new electrolytes with increased electrochemical stability. In-situ (scanning) transmission electron microscopy ((S)TEM) using an electrochemical fluid cell provides the ability to rapidly and directly characterize electrode/electrolyte interfacial reactions under battery relevant electrochemical conditions. Furthermore, as the electron beam itself causes a localized electrochemical reaction when it interacts with the electrolyte, the breakdown products that occur during the first stages of battery operation can potentially be simulated and characterized using a straightforward in-situ liquid stage (without electrochemical biasing capabilities). In this paper, we have studied the breakdown of a range of inorganic/salt complexes that are used in state-of-the-art Li-ion battery systems. The results of the in-situ (S)TEM experiments matches with previous stability tests performed during battery operation and the breakdown products and mechanisms are also consistent with known mechanisms. This analysis indicates that in-situ liquid stage (S)TEM observations can be used to directly test new electrolyte designs and provide structural insights into the origin of the solid electrolyte interphase (SEI) formation mechanism.

  7. Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy

    SciTech Connect (OSTI)

    Leenheer, Andrew Jay; Jungjohann, Katherine Leigh; Zavadil, Kevin Robert; Sullivan, John P.; Harris, Charles Thomas

    2015-03-18

    Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating and stripping processes is needed to enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) to image the first few cycles of lithium electrodeposition/dissolution in liquid aprotic electrolyte at submicron resolution. Cycling at current densities from 1 to 25 mA/cm2 leads to variations in grain structure, with higher current densities giving a more needle-like, higher surface area deposit. The effect of the electron beam was explored, and it was found that, even with minimal beam exposure, beam-induced surface film formation could alter the Li microstructure. The electrochemical dissolution was seen to initiate from isolated points on grains rather than uniformly across the Li surface, due to the stabilizing solid electrolyte interphase surface film. As a result, we discuss the implications for operando STEM liquid-cell imaging and Li-battery applications.

  8. Directly correlated transmission electron microscopy and atom probe tomography of grain boundary oxidation in a Ni-Al binary alloy exposed to high-temperature water.

    SciTech Connect (OSTI)

    Schreiber, Daniel K.; Olszta, Matthew J.; Bruemmer, Stephen M.

    2013-10-30

    Intergranular oxidation of a Ni-4Al alloy exposed to hydrogenated, high-temperature water was characterized using directly correlated transmission electron microscopy and atom probe tomography. These combined analyses revealed that discrete, 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 boundary as a result of grain boundary migration. The discrete oxide morphology, disconnected from the continuous surface oxidation, suggests intergranular solid-state internal oxidation of Al. Keywords: oxidation; grain boundaries; nickel alloys; atom probe tomography; transmission electron microscopy (TEM)

  9. Analysis of passivated A-286 stainless steel surfaces for mass spectrometer inlet systems by Auger electron and X-ray photoelectron spectroscopy and scanning electron microscopy

    SciTech Connect (OSTI)

    Ajo, Henry; Blankenship, Donnie; Clark, Elliot

    2014-07-25

    In this study, various commercially available surface treatments are being explored for use on stainless steel components in mass spectrometer inlet systems. Type A-286 stainless steel coupons, approximately 12.5 mm in diameter and 3 mm thick, were passivated with one of five different surface treatments; an untreated coupon served as a control. The surface and near-surface microstructure and chemistry of the coupons were investigated using sputter depth profiling using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). All the surface treatments studied appeared to change the surface morphology dramatically, as evidenced by lack of tool marks on the treated samples in SEM images. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7–0.9 nm thick), as well as to the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E’s silicon coating appears to be on the order of 200 nm thick.

  10. Analysis of passivated A-286 stainless steel surfaces for mass spectrometer inlet systems by Auger electron and X-ray photoelectron spectroscopy and scanning electron microscopy

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

    Ajo, Henry; Blankenship, Donnie; Clark, Elliot

    2014-07-25

    In this study, various commercially available surface treatments are being explored for use on stainless steel components in mass spectrometer inlet systems. Type A-286 stainless steel coupons, approximately 12.5 mm in diameter and 3 mm thick, were passivated with one of five different surface treatments; an untreated coupon served as a control. The surface and near-surface microstructure and chemistry of the coupons were investigated using sputter depth profiling using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). All the surface treatments studied appeared to change the surface morphology dramatically, as evidenced by lack of tool marks onmore » the treated samples in SEM images. In terms of the passivation treatment, Vendors A-D appeared to have oxide layers that were very similar in thickness to each other (0.7–0.9 nm thick), as well as to the untreated samples (the untreated sample oxide layers appeared to be somewhat larger). Vendor E’s silicon coating appears to be on the order of 200 nm thick.« less

  11. Electron Microscopy Lab

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

    of material microstructures in support of Basic Energy Science, Laboratory Directed Research and Development, DoD, DOE, Work for Others, nuclear energy, and weapons programs. ...

  12. Transmission electron microscopy study of precipitates in an artificially aged Al–12.7Si–0.7Mg alloy

    SciTech Connect (OSTI)

    Liu, Fang; Yu, Fuxiao; Zhao, Dazhi; Zuo, Liang

    2015-09-15

    An investigation of Al–12.7Si–0.7Mg alloy aged at 160 °C, 180 °C and 200 °C for 3 h was carried out in order to identify the precipitating phases. Regular transmission and high resolution electron microscopy (TEM and HREM) were employed for this purpose. The studies were focused on the dark spots and needle-shaped precipitates lying in (001){sub Al} plane. Based on the HREM observations, dark spots and needle-shaped precipitates have different characteristics. The results revealed that the ellipsoidal and needle-shaped precipitates along <100> direction of the matrix coexist in the alloy by tilting experiments at given aging condition. The ellipsoidal dark spot precipitates viewing along [001]{sub Al} is not cross-sectional image of needle-shaped precipitates along <001>{sub Al}. Needle-shaped precipitate is coherent with the matrix. The diffraction pattern associated with the ellipsoidal precipitates is consistent with β″ reported in literature. - Highlights: • Wrought Al–Si–Mg alloy has been investigated to identify the precipitating phases. • The ellipsoidal and needle-shaped precipitates coexist in wrought Al–Si–Mg alloy. • The needle-shaped and ellipsoidal precipitates exhibit different characteristics.

  13. High speed direct imaging of thin metal film ablation by movie-mode dynamic transmission electron microscopy

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

    Hihath, Sahar; Santala, Melissa K.; Cen, Xi; Campbell, Geoffrey; van Benthem, Klaus

    2016-03-11

    Obliteration of matter by pulsed laser beams is not only prevalent in science fiction movies, but finds numerous technological applications ranging from additive manufacturing over machining of micro- and nanostructured features to health care. Pulse lengths ranging from femtoseconds to nanoseconds are utilized at varying laser beam energies and pulse lengths, and enable the removal of nanometric volumes of material. While the mechanisms for removal of material by laser irradiation, i.e., laser ablation, are well understood on the micrometer length scale, it was previously impossible to directly observe obliteration processes on smaller scales due to experimental limitations for the combinationmore » of nanometer spatial and nanosecond temporal resolution. Here, we report the direct observation of metal thin film ablation from a solid substrate through dynamic transmission electron microscopy. Quantitative analysis reveals liquid-phase dewetting of the thin-film, followed by hydrodynamic sputtering of nano- to submicron sized metal droplets. We discovered unexpected fracturing of the substrate due to evolving thermal stresses. This study confirms that hydrodynamic sputtering remains a valid mechanism for droplet expulsion on the nanoscale, while irradiation induced stress fields represent limit laser processing of nanostructured materials. Ultimately, our results allow for improved safety during laser ablation in manufacturing and medical applications.« less

  14. Separating strain from composition in unit cell parameter maps obtained from aberration corrected high resolution transmission electron microscopy imaging

    SciTech Connect (OSTI)

    Schulz, T.; Remmele, T.; Korytov, M.; Markurt, T.; Albrecht, M.; Duff, A.; Lymperakis, L.; Neugebauer, J.; Chèze, C.

    2014-01-21

    Based on the evaluation of lattice parameter maps in aberration corrected high resolution transmission electron microscopy images, we propose a simple method that allows quantifying the composition and disorder of a semiconductor alloy at the unit cell scale with high accuracy. This is realized by considering, next to the out-of-plane, also the in-plane lattice parameter component allowing to separate the chemical composition from the strain field. Considering only the out-of-plane lattice parameter component not only yields large deviations from the true local alloy content but also carries the risk of identifying false ordering phenomena like formations of chains or platelets. Our method is demonstrated on image simulations of relaxed supercells, as well as on experimental images of an In{sub 0.20}Ga{sub 0.80}N quantum well. Principally, our approach is applicable to all epitaxially strained compounds in the form of quantum wells, free standing islands, quantum dots, or wires.

  15. Real time nanoscale structural evaluation of gold structures on Si (100) surface using in-situ transmission electron microscopy

    SciTech Connect (OSTI)

    Rath, A. E-mail: ashutosh.phy@gmail.com E-mail: pvsatyam22@gmail.com; Juluri, R. R.; Satyam, P. V. E-mail: ashutosh.phy@gmail.com E-mail: pvsatyam22@gmail.com

    2014-05-14

    Transport behavior of gold nanostructures on Si(100) substrate during annealing under high vacuum has been investigated using in-situ real time transmission electron microscopy (TEM). A comparative study has been done on the morphological changes due to annealing under different vacuum environments. Au thin films of thickness ∼2.0 nm were deposited on native oxide covered silicon substrate by using thermal evaporation system. In-situ real time TEM measurements at 850 °C showed the isotropic growth of rectangular/square shaped gold-silicon alloy structures. During the growth, it is observed that the alloying occurs in liquid phase followed by transformation into the rectangular shapes. For similar system, ex-situ annealing in low vacuum (10{sup −2} millibars) at 850 °C showed the spherical gold nanostructures with no Au-Si alloy formation. Under low vacuum annealing conditions, the rate of formation of the oxide layer dominates the oxide desorption rate, resulting in the creation of a barrier layer between Au and Si, which restricts the inter diffusion of Au in to Si. This work demonstrates the important role of interfacial oxide layer on the growth of nanoscale Au-Si alloy structures during the initial growth. The time dependent TEM images are presented to offer a direct insight into the fundamental dynamics of the sintering process at the nanoscale.

  16. Interaction potentials of anisotropic nanocrystals from the trajectory sampling of particle motion using in situ liquid phase transmission electron microscopy

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

    Chen, Qian; Cho, Hoduk; Manthiram, Karthish; Yoshida, Mark; Ye, Xingchen; Alivisatos, A. Paul

    2015-03-23

    We demonstrate a generalizable strategy to use the relative trajectories of pairs and groups of nanocrystals, and potentially other nanoscale objects, moving in solution which can now be obtained by in situ liquid phase transmission electron microscopy (TEM) to determine the interaction potentials between nanocrystals. Such nanoscale interactions are crucial for collective behaviors and applications of synthetic nanocrystals and natural biomolecules, but have been very challenging to measure in situ at nanometer or sub-nanometer resolution. Here we use liquid phase TEM to extract the mathematical form of interaction potential between nanocrystals from their sampled trajectories. We show the power ofmore » this approach to reveal unanticipated features of nanocrystal–nanocrystal interactions by examining the anisotropic interaction potential between charged rod-shaped Au nanocrystals (Au nanorods); these Au nanorods assemble, in a tip-to-tip fashion in the liquid phase, in contrast to the well-known side-by-side arrangements commonly observed for drying-mediated assembly. These observations can be explained by a long-range and highly anisotropic electrostatic repulsion that leads to the tip-selective attachment. As a result, Au nanorods stay unassembled at a lower ionic strength, as the electrostatic repulsion is even longer-ranged. Our study not only provides a mechanistic understanding of the process by which metallic nanocrystals assemble but also demonstrates a method that can potentially quantify and elucidate a broad range of nanoscale interactions relevant to nanotechnology and biophysics.« less

  17. Correlative transmission electron microscopy and electrical properties study of switchable phase-change random access memory line cells

    SciTech Connect (OSTI)

    Oosthoek, J. L. M.; Kooi, B. J.; Voogt, F. C.; Attenborough, K.; Verheijen, M. A.; Hurkx, G. A. M.; Gravesteijn, D. J.

    2015-02-14

    Phase-change memory line cells, where the active material has a thickness of 15 nm, were prepared for transmission electron microscopy (TEM) observation such that they still could be switched and characterized electrically after the preparation. The result of these observations in comparison with detailed electrical characterization showed (i) normal behavior for relatively long amorphous marks, resulting in a hyperbolic dependence between SET resistance and SET current, indicating a switching mechanism based on initially long and thin nanoscale crystalline filaments which thicken gradually, and (ii) anomalous behavior, which holds for relatively short amorphous marks, where initially directly a massive crystalline filament is formed that consumes most of the width of the amorphous mark only leaving minor residual amorphous regions at its edges. The present results demonstrate that even in (purposely) thick TEM samples, the TEM sample preparation hampers the probability to observe normal behavior and it can be debated whether it is possible to produce electrically switchable TEM specimen in which the memory cells behave the same as in their original bulk embedded state.

  18. Atomic-resolution study of polarity reversal in GaSb grown on Si by scanning transmission electron microscopy

    SciTech Connect (OSTI)

    Hosseini Vajargah, S.; Woo, S. Y.; Botton, G. A.; Ghanad-Tavakoli, S.; Kleiman, R. N.; Preston, J. S.

    2012-11-01

    The atomic-resolved reversal of the polarity across an antiphase boundary (APB) was observed in GaSb films grown on Si by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The investigation of the interface structure at the origin of the APB reveals that coalescence of two domains with Ga-prelayer and Sb-prelayer causes the sublattice reversal. The local strain and lattice rotation distributions of the APB, attributed to the discordant bonding length at the APB with the surrounding GaSb lattice, were further studied using the geometric phase analysis technique. The crystallographic characteristics of the APBs and their interaction with other planar defects were observed with HAADF-STEM. The quantitative agreement between experimental and simulated images confirms the observed polarities in the acquired HAADF-STEM data. The self-annihilation mechanism of the APBs is addressed based on the rotation induced by anti-site bonds and APBs' faceting.

  19. Imaging individual lanthanum atoms in zeolite Y by scanning transmission electron microscopy: evidence of lanthanum pair sites

    SciTech Connect (OSTI)

    Xu, Pinghong; Lu, Jing; Aydin, C.; Debefve, Louise M.; Browning, Nigel D.; Chen, Cong-Yan; Gates, Bruce C.

    2015-09-01

    Images of La-exchanged NaY zeolite obtained with aberration-corrected scanning transmission electron microscopy (STEM) show that about 80% of the La cations were present as site-isolated species, with the remainder in pair sites. The distance between La cations in the pair sites ranged from 1.44 to 3.84 Å, consistent with the presence of pairs of cations tilted at various angles with respect to the support surface. The actual distance between La cations in the pair sites is inferred to be approximately 3.84 Å, which is shorter than the distance between the nearest Al sites in the zeolite (4.31 Å). The results therefore suggest the presence of dimeric structures of La cations bridged with OH groups, and the presence of such species has been inferred previously on the basis of X-ray photoelectron spectroscopy (W. Grünert, U. Sauerlandt, R. Schlögl, H.G. Karge, J. Phys. Chem., 97 (1993) 1413).

  20. Structure of low-density nanoporous dielectrics revealed by low-vacuum electron microscopy and small-angle x-ray scattering

    SciTech Connect (OSTI)

    Kucheyev, S O; Toth, M; Baumann, T F; Hamza, A V; Ilavsky, J; Knowles, W R; Thiel, B L; Tileli, V; van Buuren, T; Wang, Y M; Willey, T M

    2006-06-05

    We use low-vacuum scanning electron microscopy to image directly the ligament and pore size and shape distributions of representative aerogels over a wide range of length scales ({approx} 10{sup 0}-10{sup 5} nm). The images are used for unambiguous, real-space interpretation of small-angle scattering data for these complex nanoporous systems.

  1. Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy

    SciTech Connect (OSTI)

    Yamamoto, Takashi; Kida, Akiko; Noma, Yukio; Terazono, Atsushi; Sakai, Shin-ichi

    2014-02-15

    Highlights: • A high sensitive and selective testing method for asbestos in treated materials of asbestos containing wastes was developed. • Asbestos can be determined at a limits are a few million fibers per gram and a few μg g{sup −1}. • High temperature melting treatment samples were determined by this method. Asbestos fiber concentration were below the quantitation limit in all samples, and total fiber concentrations were determined as 47–170 × 10{sup 6} g{sup −1}. - Abstract: Appropriate treatment of asbestos-containing wastes is a significant problem. In Japan, the inertization of asbestos-containing wastes based on new treatment processes approved by the Minister of the Environment is promoted. A highly sensitive method for testing asbestos fibers in inertized materials is required so that these processes can be approved. We developed a method in which fibers from milled treated materials are extracted in water by shaking, and are counted and identified by transmission electron microscopy. Evaluation of this method by using asbestos standards and simulated slag samples confirmed that the quantitation limits are a few million fibers per gram and a few μg/g in a sample of 50 mg per filter. We used this method to assay asbestos fibers in slag samples produced by high-temperature melting of asbestos-containing wastes. Fiber concentrations were below the quantitation limit in all samples, and total fiber concentrations were determined as 47–170 × 10{sup −6} f/g. Because the evaluation of treated materials by TEM is difficult owing to the limited amount of sample observable, this testing method should be used in conjunction with bulk analytical methods for sure evaluation of treated materials.

  2. A low energy electron microscopy study of the initial growth, structure, and thermal stability of 4,4{sup '}-biphenyldicarboxylic acid domains on Cu(001)

    SciTech Connect (OSTI)

    Khokhar, Fawad S.; Gastel, Raoul van; Schwarz, Daniel; Zandvliet, Harold J. W.; Poelsema, Bene

    2011-09-28

    The growth of 4,4{sup '}-biphenyldicarboxylic acid (BDA) on Cu(001) has been studied using low energy electron microscopy and selective area low energy electron diffraction. The emergence of large islands and hydrogen bonding to perpendicularly oriented, adjacent molecules is confirmed. The two benzene rings of adsorbed BDA are twisted along the molecular axis. Unconventional growth of the domains, followed by a second nucleation stage, is observed at room temperature. This unanticipated feature is attributed to the accumulation of stress in the islands. Ostwald ripening in the films and the decay of BDA domains at 448 K exhibits features that are consistent with diffusion limited behavior.

  3. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

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

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V.; Reed, Bryan W.; Lau, June W.

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incomingmore » dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.« less

  4. GHz laser-free time-resolved transmission electron microscopy: A stroboscopic high-duty-cycle method

    SciTech Connect (OSTI)

    Qiu, Jiaqi; Zhu, Yimei; Ha, Gwanghui; Jing, Chunguang; Baryshev, Sergey V.; Reed, Bryan W.; Lau, June W.

    2015-11-10

    In this study, a device and a method for producing ultrashort electron pulses with GHz repetition rates via pulsing an input direct current (dc) electron beam are provided. The device and the method are based on an electromagnetic-mechanical pulser (EMMP) that consists of a series of transverse deflecting cavities and magnetic quadrupoles. The EMMP modulates and chops the incoming dc electron beam and converts it into pico- and sub-pico-second electron pulse sequences (pulse trains) at >1 GHz repetition rates, as well as controllably manipulates the resulting pulses. Ultimately, it leads to negligible electron pulse phase-space degradation compared to the incoming dc beam parameters. The temporal pulse length and repetition rate for the EMMP can be continuously tunable over wide ranges.

  5. Determination of redox reaction rates and orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  6. High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam

    DOE Patents [OSTI]

    Brown, Jr., R. Malcolm; Barnes, Zack; Sawatari, Chie; Kondo, Tetsuo

    2008-02-26

    The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

  7. Temperature-induced martensite in magnetic shape memory Fe{sub 2}MnGa observed by photoemission electron microscopy

    SciTech Connect (OSTI)

    Jenkins, Catherine; Scholl, Andreas; Kainuma, R.; Elmers, Hans-Joachim; Omori, Toshihiro

    2012-01-18

    The magnetic domain structure in single crystals of a Heusler shape memory compound near the composition Fe{sub 2}MnGa was observed during phase transition by photoelectron emission microscopy at Beamline 11.0.1.1 of the Advanced Light Source. The behavior is comparable with recent observations of an adaptive martensite phase in prototype Ni{sub 2}MnGa, although the pinning in the recent work is an epitaxial interface and in this work the e#11;ective pinning plane is a boundary between martensitic variants that transform in a self-accommodating way from the single crystal austenite phase present at high temperatures. Temperature dependent observations of the twinning structure give information as to the coupling behavior between the magnetism and the structural evolution.

  8. Combining nanocalorimetry and dynamic transmission electron microscopy for in situ characterization of materials processes under rapid heating and cooling

    SciTech Connect (OSTI)

    Grapes, Michael D.; LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H.; Friedman, Lawrence H.; LaVan, David A.; Weihs, Timothy P.

    2014-08-15

    Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here, we couple a nanocalorimeter with an extremely fast in situ microstructural characterization tool to identify the physical origin of rapid enthalpic signals. More specifically, we describe the development of a system to enable in situ nanocalorimetry experiments in the dynamic transmission electron microscope (DTEM), a time-resolved TEM capable of generating images and electron diffraction patterns with exposure times of 30 ns500 ns. The full experimental system consists of a modified nanocalorimeter sensor, a custom-built in situ nanocalorimetry holder, a data acquisition system, and the DTEM itself, and is capable of thermodynamic and microstructural characterization of reactions over a range of heating rates (10{sup 2} K/s10{sup 5} K/s) accessible by conventional (DC) nanocalorimetry. To establish its ability to capture synchronized calorimetric and microstructural data during rapid transformations, this work describes measurements on the melting of an aluminum thin film. We were able to identify the phase transformation in both the nanocalorimetry traces and in electron diffraction patterns taken by the DTEM. Potential applications for the newly developed system are described and future system improvements are discussed.

  9. Current Titles

    SciTech Connect (OSTI)

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  10. Phase Boundary Propagation in Li-Alloying Battery Electrodes Revealed by Liquid-Cell Transmission Electron Microscopy

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

    Leenheer, Andrew J.; Jungjohann, Katherine L.; Zavadil, Kevin R.; Harris, Charles T.

    2016-05-31

    Battery cycle life is directly influenced by the microstructural changes occurring in the electrodes during charge and discharge cycles. In this study, we image in situ the nanoscale phase evolution in negative electrode materials for Li-ion batteries using a fully enclosed liquid cell in a transmission electron microscope (TEM) to reveal early degradation that is not evident in the charge–discharge curves. To compare the electrochemical phase transformation behavior between three model materials, thin films of amorphous Si, crystalline Al, and crystalline Au were lithiated and delithiated at controlled rates while immersed in a commercial liquid electrolyte. This method allowed formore » the direct observation of lithiation mechanisms in nanoscale negative electrodes, revealing that a simplistic model of a surface-to-interior lithiation front is insufficient. For the crystalline films, a lithiation front spread laterally from a few initial nucleation points, with continued grain nucleation along the growing interface. The intermediate lithiated phases were identified using electron diffraction, and high-resolution postmortem imaging revealed the details of the final microstructure. Lastly, our results show that electrochemically induced solid–solid phase transformations can lead to highly concentrated stresses at the laterally propagating phase boundary which should be considered for future designs of nanostructured electrodes for Li-ion batteries.« less

  11. Element-specific study of epitaxial NiO/Ag/CoO/Fe films grown on vicinal Ag(001) using photoemission electron microscopy

    SciTech Connect (OSTI)

    Meng, Y.; Li, J.; Tan, A.; Jin, E.; Son, J.; Park, J. S.; Doran, A.; Young, A. T.; Scholl, A.; Arenholz, E.; Wu, J.; Hwang, C.; Zhao, H. W.; Qiu, Z. Q.

    2011-01-10

    NiO/Ag/CoO/Fe single crystalline films are grown epitaxially on a vicinal Ag(001) substrate using molecular beam epitaxy and investigated by photoemission electron microscopy. We find that after zero-field cooling, the in-plane Fe magnetization switches from parallel to perpendicular direction of the atomic steps of the vicinal surface at thinner CoO thickness but remains in its original direction parallel to the steps at thicker CoO thickness. CoO and NiO domain imaging result shows that both CoO/Fe and NiO/CoO spins are perpendicularly coupled, suggesting that the Fe magnetization switching may be associated with the rotatable-frozen spin transition of the CoO film.

  12. Atomic arrangement at ZnTe/CdSe interfaces determined by high resolution scanning transmission electron microscopy and atom probe tomography

    SciTech Connect (OSTI)

    Bonef, Bastien; Rouvire, Jean-Luc; Jouneau, Pierre-Henri; Bellet-Amalric, Edith; Grard, Lionel; Mariette, Henri; Andr, Rgis; Bougerol, Catherine; Grenier, Adeline

    2015-02-02

    High resolution scanning transmission electron microscopy and atom probe tomography experiments reveal the presence of an intermediate layer at the interface between two binary compounds with no common atom, namely, ZnTe and CdSe for samples grown by Molecular Beam Epitaxy under standard conditions. This thin transition layer, of the order of 1 to 3 atomic planes, contains typically one monolayer of ZnSe. Even if it occurs at each interface, the direct interface, i.e., ZnTe on CdSe, is sharper than the reverse one, where the ZnSe layer is likely surrounded by alloyed layers. On the other hand, a CdTe-like interface was never observed. This interface knowledge is crucial to properly design superlattices for optoelectronic applications and to master band-gap engineering.

  13. A transmission electron microscopy study of the deformation behavior underneath nanoindents in nano-scale Al-TiN multilayered composites

    SciTech Connect (OSTI)

    Bhattacharyya, Dhriti; Mara, Nathan A; Dickerson, Patricia O; Misra, Amit; Hoagland, R G

    2009-01-01

    Nano-scale multilayered Al-TiN composites were deposited with DC magnetron sputtering technique in two different layer thickness ratios - Al:TiN = 1:1 and Al:TiN = 9:1. The Al layer thickness varied from 2 nm to 450 nm. The hardness of the samples was tested by nanoindentation using a Berkovich tip. Cross-sectional Transmission Electron Microscopy (TEM) was carried out on samples extracted with Focused Ion Beam (FIB) from below the nanoindents. This paper presents the results of the hardness tests in the Al-TiN multilayers with the two different thickness ratios and the observations from the cross-sectional TEM studies of the regions underneath the indents. These studies showed remarkable strength in the multilayers, as well as some very interesting deformation behavior in the TiN layers at extremely small length scales, where the hard TiN layers undergo co-deformation with the Al layers.

  14. EXTRACTION OF FRACTURE-MECHANICS AND TRANSMISSION-ELECTRON-MICROSCOPY SAMPLES FROM TRITIUM-EXPOSED RESERVOIRS USING ELECTRIC-DISCHARGE MACHINING

    SciTech Connect (OSTI)

    Morgan, M; Ken Imrich, K; Michael Tosten, M

    2006-08-31

    The Enhanced Surveillance Campaign is funding a program to investigate tritium aging effects on the structural properties of tritium reservoir steels. The program is designed to investigate how the structural properties of reservoir steels change during tritium service and to examine the role of microstructure and reservoir manufacturing on tritium compatibility. New surveillance tests are also being developed that can better gauge the long-term effects of tritium and its radioactive decay product, helium-3, on the properties of reservoir steels. In order to conduct these investigations, three types of samples are needed from returned reservoirs: tensile, fracture mechanics, and transmission-electron microscopy (TEM). An earlier report demonstrated how the electric-discharge machining (EDM) technique can be used for cutting tensile samples from serial sections of a 3T reservoir and how yield strength, ultimate strength and elongation could be measured from those samples. In this report, EDM was used successfully to section sub-sized fracture-mechanics samples from the inner and outer walls of a 3T reservoir and TEM samples from serial sections of a 1M reservoir. This report fulfills the requirements for the FY06 Level 3 milestone, TSR 15.1 ''Cut Fracture-Mechanics Samples from Tritium-Exposed Reservoir'' and TSR 15.2 ''Cut Transmission-electron-microscopy foils from Tritium-Exposed Reservoir'' for the Enhance Surveillance Campaign (ESC). This was in support of ESC L2-1870 Milestone-''Provide aging and lifetime assessments of selected components and materials for multiple enduring stockpile systems''.

  15. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

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

    Zweiacker, K.; McKeown, J. T.; Liu, C.; LaGrange, T.; Reed, B. W.; Campbell, G. H.; Wiezorek, J. M. K.

    2016-08-04

    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of themore » metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ~1.3 m s–1 to ~2.5 m s–1 during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s–1 have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. As a result, using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.« less

  16. Rapid Laser Induced Crystallization of Amorphous NiTi Films Observed by Nanosecond Dynamic Transmission Electron Microscopy (DTEM)

    SciTech Connect (OSTI)

    LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S

    2010-03-01

    The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.

  17. An in-situ study of magnetic domain structures in undercooled Fe-29.5 at. %Pd magnetostrictive alloys by Lorentz microscopy and electron holography

    SciTech Connect (OSTI)

    Sun, Wen; Xu, Xianhui; Liu, Jian E-mail: xiawxing@nimte.ac.cn; Xia, Weixing E-mail: xiawxing@nimte.ac.cn; Yan, Aru

    2015-04-28

    Understanding of correlation between magnetic domain structure and functional properties is of importance for the magnetic field driven phase transition (e.g., martensitic transformation) or microstructure variation (e.g., twin boundary motion) materials. In this work, we report a Fe-29.5 at. %Pd shape memory alloy treated by undercooling processing upon a degree of 320?K below the liquid temperature. The effect of high undercooling on the solidified microstructure and martensitic transformation temperatures was investigated. By in-situ Lorentz transmission electron microscopy and electron holography, magnetic domain structure and the field-induced domain wall motion behavior in as-cast and undercooled samples have been schematically studied. The irregular domain structure can be observed in these alloys. On the application of a field up to 300?Oe, the domain walls for both samples are able to move along the direction of the external magnetic field, but structural transition and rearrangement of variants are not observed in the undercooled alloy. The large magnetostriction of Fe-29.5 at. %Pd undercooled alloy originates from the irregular domain walls motion instead of the rearrangement of martensitic twin variants.

  18. Direct comparison between X-ray nanotomography and scanning electron microscopy for the microstructure characterization of a solid oxide fuel cell anode

    SciTech Connect (OSTI)

    Quey, R.; Suhonen, H.; Laurencin, J.; Cloetens, P.; Bleuet, P.

    2013-04-15

    X-ray computed nanotomography (nano-CT) and scanning electron microscopy (SEM) have been applied to characterize the microstructure of a Solid Oxide Fuel Cell (SOFC) anode. A direct comparison between the results of both methods is conducted on the same region of the microstructure to assess the spatial resolution of the nano-CT microstructure, SEM being taken as a reference. A registration procedure is proposed to find out the position of the SEM image within the nano-CT volume. It involves a second SEM observation, which is taken along an orthogonal direction and gives an estimate reference SEM image position, which is then refined by an automated optimization procedure. This enables an unbiased comparison between the cell porosity morphologies provided by both methods. In the present experiment, nano-CT is shown to underestimate the number of pores smaller than 1 ?m and overestimate the size of the pores larger than 1.5 ?m. - Highlights: ? X-ray computed nanotomography (nano-CT) and SEM are used to characterize an SOFC anode. ? A methodology is proposed to compare the nano-CT and SEM data on the same region. ? The spatial resolution of the nano-CT data is assessed from that comparison.

  19. 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

    2014-03-26

    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.

  20. The discrepancies between theory and experiment in the optical emission of monolayer In(Ga)N quantum wells revisited by transmission electron microscopy

    SciTech Connect (OSTI)

    Suski, T.; Gorczyca, I.; Skrobas, K.; Schulz, T.; Albrecht, M.; Wang, X. Q.; Christensen, N. E.; Svane, A.

    2014-05-05

    Quantitative high resolution transmission electron microscopy studies of intentionally grown 1InN/nGaN short-period superlattices (SLs) were performed. The structures were found to consist of an In{sub x}Ga{sub 1−x}N monolayer with an Indium content of x = 0.33 instead of the intended x = 1. Self-consistent calculations of the band structures of 1In{sub 0.33}Ga{sub 0.67}N/nGaN SLs were carried out, including a semi-empirical correction for the band gaps. The calculated band gap, E{sub g,} as well as its pressure derivative, dE{sub g}/dp, are in very good agreement with the measured photoluminescence energy, E{sub PL}, and its pressure derivative, dE{sub PL}/dp, for a series of 1In{sub 0.33}Ga{sub 0.67}N/nGaN samples with n ranging from 2 to 40. This resolves a discrepancy found earlier between measured and calculated optical emission properties, as those calculations were made with the assumption of a 1InN/nGaN SL composition.

  1. Demonstration of an Electrochemical Liquid Cell for Operando Transmission Electron Microscopy Observation of the Lithiation/Delithiation Behavior of Si Nanowire Battery Anodes

    SciTech Connect (OSTI)

    Gu, Meng; Parent, Lucas R.; Mehdi, Beata L.; Unocic, Raymond R.; Mcdowell, Matthew T.; Sacci, Robert L.; Xu, Wu; Connell, Justin G.; Xu, Pinghong; Abellan Baeza, Patricia; Chen, Xilin; Zhang, Yaohui; Perea, Daniel E.; Evans, James E.; Lauhon, Lincoln; Zhang, Jiguang; Liu, Jun; Browning, Nigel D.; Cui, Yi; Arslan, Ilke; Wang, Chong M.

    2013-12-11

    Over the last few years, in-situ transmission electron microscopy (TEM) studies of lithium ion batteries using an open-cell configuration have helped us to gain fundamental insights into the structural and chemical evolution of the electrode materials in real time. In the standard open-cell configuration, the electrolyte is either solid lithium oxide or an ionic liquid, which is point-contacted with the electrode. This cell design is inherently different from a real battery, where liquid electrolyte forms conformal contact with electrode materials. The knowledge learnt from open cells can deviate significantly from the real battery, calling for operando TEM technique with conformal liquid electrolyte contact. In this paper, we developed an operando TEM electrochemical liquid cell to meet this need, providing the configuration of a real battery and in a relevant liquid electrolyte. To demonstrate this novel technique, we studied the lithiation/delithiation behavior of single Si nanowires. Some of lithiation/delithation behaviors of Si obtained using the liquid-cell are consistent with the results from the open-cell studies. However, we also discovered new insights different from the open cell configuration - the dynamics of the electrolyte and, potentially, a future quantitative characterization of the SEI layer formation and structural and chemical evolution.

  2. In-situ high resolution transmission electron microscopy observation of silicon nanocrystal nucleation in a SiO{sub 2} bilayered matrix

    SciTech Connect (OSTI)

    Yang, T. C.-J. Wu, L.; Lin, Z.; Jia, X.; Puthen-Veettil, B.; Zhang, T.; Conibeer, G.; Perez-Wurfl, I.; Kauffmann, Y.; Rothschild, A.

    2014-08-04

    Solid-state nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix was observed at temperatures as low as 450?C. This was achieved by aberration corrected high-resolution transmission electron microscopy (HRTEM) with real-time in-situ heating up to 600?C. This technique is a valuable characterization tool especially with the recent interest in Si nanostructures for light emitting devices, non-volatile memories, and third-generation photovoltaics which all typically require a heating step in their fabrication. The control of size, shape, and distribution of the Si nanocrystals are critical for these applications. This experimental study involves in-situ observation of the nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix fabricated through radio frequency co-sputtering. The results show that the shapes of Si nanocrystals in amorphous SiO{sub 2} bilayered matrices are irregular and not spherical, in contrast to many claims in the literature. Furthermore, the Si nanocrystals are well confined within their layers by the amorphous SiO{sub 2}. This study demonstrates the potential of in-situ HRTEM as a tool to observe the real time nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix. Furthermore, ideas for improvements on this in-situ heating HRTEM technique are discussed.

  3. Abnormal cubic-tetragonal phase transition of barium strontium titanate nanoparticles studied by in situ Raman spectroscopy and transmission electron microscopy heating experiments

    SciTech Connect (OSTI)

    Zhang, Yin; Chen, Chen; Gao, Ran; Xia, Feng; Li, YueSheng; Che, Renchao

    2015-11-02

    Phase stability of the ferroelectric materials at high temperature is extremely important to their device performance. Ba{sub x}Sr{sub 1−x}TiO{sub 3} (BST) nanoparticles with different Sr contents (x = 1, 0.91, 0.65, 0.4, and 0) are prepared by a facile hydrothermal method. Using Raman spectroscopy and transmission electron microscopy (TEM) analyses under in situ heating conditions (up to 300 °C), the phase transitions of BST nanoparticles between 25 °C and 280 °C are comprehensively investigated. The original Curie temperature of BST nanoparticles decreases abruptly with the increase in Sr content, which is more obvious than in the bulk or film material. Besides, an abnormal phase transition from cubic to tetragonal structure is observed from BST nanoparticles and the transition temperature rises along with the increase in Sr content. Direct TEM evidences including a slight lattice distortion have been provided. Differently, BaTiO{sub 3} nanoparticles remained in the tetragonal phase during the above temperature ranges.

  4. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

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

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Nimore » $$_{50}$$Co$$_{50}$$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.« less

  5. The structures and dynamics of atomic and molecular adsorbates on metal surfaces by scanning tunneling microscopy and low energy electron diffraction

    SciTech Connect (OSTI)

    Yoon, Hyungsuk Alexander

    1996-12-01

    Studies of surface structure and dynamics of atoms and molecules on metal surfaces are presented. My research has focused on understanding the nature of adsorbate-adsorbate and adsorbate-substrate interactions through surface studies of coverage dependency and coadsorption using both scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The effect of adsorbate coverage on the surface structures of sulfur on Pt(111) and Rh(111) was examined. On Pt(111), sulfur forms p(2x2) at 0.25 ML of sulfur, which transforms into a more compressed ({radical}3x{radical}3)R30{degrees} at 0.33 ML. On both structures, it was found that sulfur adsorbs only in fcc sites. When the coverage of sulfur exceeds 0.33 ML, it formed more complex c({radical}3x7)rect structure with 3 sulfur atoms per unit cell. In this structure, two different adsorption sites for sulfur atoms were observed - two on fcc sites and one on hcp site within the unit cell.

  6. Scanning Electron Microscopy Analysis of Fuel/Matrix Interaction Layers in Highly-Irradiated UMo Dispersion Fuel Plates with Al and AlSi Alloy Matrices

    SciTech Connect (OSTI)

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Brandon D. Miller; Jian Gan; Adam B. Robinson; Pavel Medvedev; James Madden; Dan Wachs; Mitch Meyer

    2014-04-01

    In order to investigate how the microstructure of fuel/matrix-interaction (FMI) layers change during irradiation, different U7Mo dispersion fuel plates have been irradiated to high fission density and then characterized using scanning electron microscopy (SEM). Specifially, samples from irradiated U7Mo dispersion fuel elements with pure Al, Al2Si and AA4043 (~4.5 wt.%Si) matrices were SEM characterized using polished samples and samples that were prepared with a focused ion beam (FIB). Features not observable for the polished samples could be captured in SEM images taken of the FIB samples. For the Al matrix sample, a relatively large FMI layer develops, with enrichment of Xe at the FMI layer/Al matrix interface and evidence of debonding. Overall, a significant penetration of Si from the FMI layer into the U7Mo fuel was observed for samples with Si in the Al matrix, which resulted in a change of the size (larger) and shape (round) of the fission-gas bubbles. Additionally, solid-fission-product phases were observed to nucleate and grow within these bubbles. These changes in the localized regions of the microstructure of the U7Mo may contribute to changes observed in the macroscopic swelling of fuel plates with AlSi matrices.

  7. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

    SciTech Connect (OSTI)

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Ni$_{50}$Co$_{50}$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.

  8. News Item

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

    Efficient Conversion of Carbon Monoxide to Liquid Fuel Electron microscopy images of copper electrodes at various magnifications. Top row: the copper nanoparticle electrode. Middle and bottom row: OD-Cu electrodes created using two different methods to vary the material properties. Scientific Achievement A multidisciplinary team of users at the National Center for Electron Microscopy (NCEM) created copper-derived electrocatalysts that efficiently produce appreciable amounts of ethanol from

  9. NREL: Measurements and Characterization - Analytical Microscopy

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

    Analytical Microscopy Analytical microscopy uses various high-resolution techniques to obtain information about materials on the atomic scale. It is one of the most powerful tools available for understanding a material's basic structure, chemistry, and morphology. We use two complementary types of analytical microscopy - electron microscopy and scanning probe microscopy - together with a variety of state-of-the-art imaging and analytical tools to capture data about photovoltaic (PV) materials

  10. News Item

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

    4, 2016 Time: 11:00 am Speaker: Ondrej Krivanek, Nion Title: Atomic-Resolution and Vibrational Studies of Materials by Aberration-Corrected Scanning Transmission Electron Microscopy Location: 67-3111 Chemla Room Abstract: Aberration-corrected scanning transmission electron microscopes (AC-STEMs) are able to form electron probes as small as 0.5 Å in diameter, and they can image and spectroscopically analyze single atoms in-situ. NCEM and Nion have pioneered many of these advances. Nion's main

  11. Evolution of titania nanotubes-supported WO{sub x} species by in situ thermo-Raman spectroscopy, X-ray diffraction and high resolution transmission electron microscopy

    SciTech Connect (OSTI)

    Cortes-Jacome, M.A.; Angeles-Chavez, C.; Morales, M.; Lopez-Salinas, E.; Toledo-Antonio, J.A.

    2007-10-15

    Structural evolution of WO{sub x} species on the surface of titania nanotubes was followed by in situ thermo-Raman spectroscopy. A total of 15 wt% of W atoms were loaded on the surface of a hydroxylated titania nanotubes by impregnation with ammonium metatungstate solution and then, the sample was thermally treated in a Linkam cell at different temperatures in nitrogen flow. The band characteristic of the W=O bond was observed at 962 cm{sup -1} in the dried sample, which vanished between 300 and 700 deg. C, and reappear again after annealing at 800 deg. C, along with a broad band centered at 935 cm{sup -1}, attributed to the v{sub 1} vibration of W=O in tetrahedral coordination. At 900 and 1000 deg. C, the broad band decomposed into four bands at 923, 934, 940 and 950 cm{sup -1}, corresponding to the symmetric and asymmetric vibration of W=O bonds in Na{sub 2}WO{sub 4} and Na{sub 2}W{sub 2}O{sub 7} phases as determined by X-ray diffraction and High resolution transmission electron microscopy (HRTEM). The structure of the nanotubular support was kept at temperatures below 450 deg. C, thereafter, it transformed into anatase being stabilized at temperatures as high as 900 deg. C. At 1000 deg. C, anatase phase partially converted into rutile. After annealing at 1000 deg. C, a core-shell model material was obtained, with a shell of ca. 5 nm thickness, composed of sodium tungstate nanoclusters, and a core composed mainly of rutile TiO{sub 2} phase. - Graphical abstract: Titania nanotubes loaded with 15 wt% W atoms were characterized from room temperature (rt) to 1000 deg. C by thermo-Raman spectroscopy in N{sub 2}. At 1000 deg. C, a core-shell model material was obtained, with a shell thickness of ca. 5 nm composed by nanoclusters of sodium tungstate, and a core composed mainly of rutile TiO{sub 2} phase.

  12. 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 Thelander, Erik; Rauschenbach, Bernd

    2014-03-24

    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.

  13. X-ray microscopy. Beyond ensemble averages

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

    Ice, Gene E.; Budai, John D.

    2015-06-23

    This work exemplifies emerging tools to characterize local materials structure and dynamics, made possible by powerful X-ray synchrotron and transmission electron microscopy methods.

  14. Stress Corrosion Crack Growth Rate Testing and Analytical Electron Microscopy of Alloy 600 as a Function of Pourbaix Space and Microstructure

    SciTech Connect (OSTI)

    N. Lewis; S.A. Attanasio; D.S. Morton; G.A. Young

    2000-10-04

    Stress corrosion crack (SCC) growth rate tests and analytical electron microscopy (AEM) studies were performed over a broad range of environments and heat treatments of Alloy 600. This effort was conducted to correlate bulk environmental conditions such as pH and electrochemical potential (EcP) with the morphology of the SCC crack. Development of a library of AEM morphologies formed by SCC in different environments is an important step in identifying the conditions that lead to SCC in components. Additionally, AEM examination of stress corrosion cracks formed in different environments and microstructures lends insight into the mechanism(s) of stress corrosion cracking. Testing was conducted on compact tension specimens in three environments: a mildly acidic oxidizing environment containing sulfate ions, a caustic environment containing 10% NaOH, and hydrogenated near-neutral buffered water. Additionally, stress corrosion cracking testing of a smooth specimen was conducted in hydrogenated steam. The following heat treatments of Alloy 600 were examined: mill annealed at 980 C (near-neutral water), mill annealed at 1010 C (steam), sensitized (acid and caustic), and mill annealed + healed to homogenize the grain boundary Cr concentration (caustic). Crack growth rate (CGR) testing showed that sensitized Alloy 600 tested in the mildly acidic, oxidizing environment containing sulfate ions produced the fastest cracking ({approx} 8.8 {micro}m/hr at 260 C), and AEM examination revealed evidence of sulfur segregation to the crack tip. The caustic environment produced slower cracking ({approx} 0.4 {micro}m/hr at 307 C) in the mill annealed + healed heat treatment but no observed cracking in the sensitized condition. In the caustic environment, fully oxidized carbides were present in the crack wake but not ahead of the crack tip. In near-neutral buffered water at 338 C, the CGR was a function of dissolved hydrogen in the water and exhibited a maximum (0.17 {micro}m/hr) near the

  15. Fine precipitation scenarios of AlZnMg(Cu) alloys revealed by advanced atomic-resolution electron microscopy study Part I: Structure determination of the precipitates in AlZnMg(Cu) alloys

    SciTech Connect (OSTI)

    Liu, J.Z.; Chen, J.H.; Yuan, D.W.; Wu, C.L.; Zhu, J.; Cheng, Z.Y.

    2015-01-15

    Although they are among the most important precipitation-hardened materials for industry applications, the high-strength AlZnMg(Cu) alloys have thus far not yet been understood adequately about their underlying precipitation scenarios in relation with the properties. This is partly due to the fact that the structures of a number of different precipitates involved in electron microscopy in association with quantitative image simulations have to be employed; a systematic study of these hardening precipitates in different alloys is also necessary. In Part I of the present study, it is shown that there are five types of structurally different precipitates including the equilibrium η-phase precipitate. Using two state-of-the-art atomic-resolution imaging techniques in electron microscopy in association with quantitative image simulations, we have determined and clarified all the unknown precipitate structures. It is demonstrated that atomic-resolution imaging can directly suggest approximate structure models, whereas quantitative image analysis can refine the structure details that are much smaller than the resolution of the microscope. This combination is crucially important for solving the difficult structure problems of the strengthening precipitates in AlZnMg(Cu) alloys. - Highlights: Part I: • We determine and verify all the key precipitate structures in AlMgZn(Cu) alloys. • We employ aberration-corrected scanning transmission electron microscopy (STEM). • We use aberration-corrected high-resolution TEM (HRTEM) for the investigations. • We obtain atomic-resolution images of the precipitates and model their structures. • We refine all precipitate structures with quantitative image simulation analysis. Part II: • The hardening precipitates in AlZnMg alloys shall be classified into two groups. • Two precipitation scenarios coexist in the alloys. • The precipitation behavior of such an alloy depends on the alloy's composition. • Very detailed phase

  16. Electrostatically focused addressable field emission array chips (AFEA's) for high-speed massively parallel maskless digital E-beam direct write lithography and scanning electron microscopy

    DOE Patents [OSTI]

    Thomas, Clarence E.; Baylor, Larry R.; Voelkl, Edgar; Simpson, Michael L.; Paulus, Michael J.; Lowndes, Douglas H.; Whealton, John H.; Whitson, John C.; Wilgen, John B.

    2002-12-24

    Systems and methods are described for addressable field emission array (AFEA) chips. A method of operating an addressable field-emission array, includes: generating a plurality of electron beams from a pluralitly of emitters that compose the addressable field-emission array; and focusing at least one of the plurality of electron beams with an on-chip electrostatic focusing stack. The systems and methods provide advantages including the avoidance of space-charge blow-up.

  17. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  18. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  19. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  20. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  1. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  2. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Print Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material and metals, particularly how organics affect mobility, and its potential for

  3. Extracellular Proteins Promote Zinc Sulfide Aggregation

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

    Extracellular Proteins Promote Zinc Sulfide Aggregation Extracellular Proteins Promote Zinc Sulfide Aggregation Print Wednesday, 26 September 2007 00:00 Researchers from the ALS, Berkeley Lab's National Center for Electron Microscopy (NCEM), and Lawrence Livermore National Laboratory analyzed biofilm samples rich in zinc sulfide and dominated by sulfate-reducing bacteria, which were collected from lead-zinc mine waters. The researchers were curious about the relationship of the organic material

  4. Using real-time electron microscopy to explore the effects of transition-metal composition on the local thermal stability in charged LixNiyMnzCo1-y-zO2 cathode materials

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

    Hwang, Sooyeon; Kim, Seung Min; Bak, Seong -Min; Kim, Se Young; Cho, Byung -Won; Chung, Kyung Yoon; Lee, Jeong Yong; Stach, Eric A.; Chang, Wonyoung

    2015-05-08

    In this study, we use in-situ transmission electron microcopy (TEM) to investigate the thermal decomposition that occurs at the surface of charged LixNiyMnzCo1-y-zO2 (NMC) cathode materials of different composition (with y, z=0.8, 0.1 and 0.6, 0.2 and 0.4, 0.3), after they have been charged to their practical upper limit voltage (4.3V). By heating these materials inside the TEM, we are able to directly characterize near surface changes in both their electronic structure (using electron energy loss spectroscopy) and crystal structure and morphology (using electron diffraction and bright-field imaging). The most Ni-rich material (y, z = 0.8, 0.1) is found tomore » be thermally unstable at significantly lower temperatures than the other compositions – this is manifested by changes in both the electronic structure and the onset of phase transitions at temperatures as low as 100°C. Electron energy loss spectroscopy indicates that the thermally induced reduction of Ni ions drives these changes, and that this is exacerbated by the presence of an additional redox reaction that occurs at 4.2V in the y, z = 0.8, 0.1 material. Exploration of individual particles shows that there are substantial variations in the onset temperatures and overall extent of these changes. Of the compositions studied, the composition of y, z = 0.6, 0.2 has the optimal combination of high energy density and reasonable thermal stability. The observations herein demonstrate that real time electron microscopy provide direct insight into the changes that occur in cathode materials with temperature, allowing optimization of different alloy concentrations to maximize overall performance.« less

  5. Electron

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

    density measurement by differential interferometry W. X. Ding, D. L. Brower, B. H. Deng, and T. Yates Electrical Engineering Department, University of California-Los Angeles, Los Angeles, California 90095 ͑Received 5 May 2006; presented on 10 May 2006; accepted 16 June 2006; published online 26 September 2006͒ A novel differential interferometer is being developed to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency

  6. Analytical electron microscopy investigation of elemental composition and bonding structure at the Sb-doped Ni-fully-silicide/SiO{sub 2} interface

    SciTech Connect (OSTI)

    Kawasaki, Naohiko; Sugiyama, Naoyuki; Otsuka, Yuji; Hashimoto, Hideki; Kurata, Hiroki; Isoda, Seiji

    2011-03-15

    It is very important to control the elemental composition and bonding structure at the gate electrode/gate dielectrics interface in metal-oxide-semiconductor transistor devices because this determines the threshold voltage of the gate electrode. In this study, we investigated the structure at the interface between the antimony (Sb)-doped nickel-fully-silicide gate electrode and SiO{sub 2} dielectrics by employing high-spatial resolution techniques such as energy dispersive x-ray spectroscopy and electron energy-loss spectroscopy using a scanning transmission electron microscope. In one region, we found a thin nickel layer at the NiSi/SiO{sub 2} interface originating from the migration of native oxide at the face of the poly-silicon. In another region, a Sb pileup was detected at the NiSi/SiO{sub 2} interface where the Ni L{sub 3}-edge spectrum showed Ni-Sb bonding, then it was suggested that Sb atoms exist at the bottom of NiSi, substituting for Si atoms in NiSi.

  7. Electron

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

    Electron thermal transport within magnetic islands in the reversed-field pinch a... H. D. Stephens, 1,b͒ D. J. Den Hartog, 1,3 C. C. Hegna, 1,2 and J. A. Reusch 1 1 Department of Physics, University of Wisconsin-Madison, 1150 University Ave., Madison, Wisconsin 53706, USA 2 Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA 3 Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of

  8. Unexpected bismuth concentration profiles in metal-organic vapor phase epitaxy-grown Ga(As{sub 1−x}Bi{sub x})/GaAs superlattices revealed by Z-contrast scanning transmission electron microscopy imaging

    SciTech Connect (OSTI)

    Wood, A. W.; Babcock, S. E.; Guan, Y.; Forghani, K.; Anand, A.; Kuech, T. F.

    2015-03-01

    A set of GaAs{sub 1−x}Bi{sub x}/GaAs multilayer quantum-well structures was deposited by metal-organic vapor phase epitaxy at 390 °C and 420 °C. The precursor fluxes were introduced with the intent of growing discrete and compositionally uniform GaAs{sub 1−x}Bi{sub x} well and GaAs barrier layers in the epitaxial films. High-resolution high-angle annular-dark-field (or “Z-contrast”) scanning transmission electron microscopy imaging revealed concentration profiles that were periodic in the growth direction, but far more complicated in shape than the intended square wave. The observed composition profiles could explain various reports of physical properties measurements that suggest compositional inhomogeneity in GaAs{sub 1−x}Bi{sub x} alloys as they currently are grown.

  9. Characterisation of amorphous silica in air-oxidised Ti3SiC2 at 500-1000 °C using secondary-ion mass spectrometry, nuclear magnetic resonance and transmission electron microscopy

    SciTech Connect (OSTI)

    Pang, W K; Low, I M; Hanna, J V

    2010-05-18

    In this paper we have described the use of secondary-ion mass spectrometry (SIMS), solid state {sup 29}Si magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM) to detect the existence of amorphous silica in Ti{sub 3}SiC{sub 2} oxidised at 500-1000 C. The formation of amorphous SiO{sub 2} and growth of crystalline TiO{sub 2} with temperature was monitored using dynamic SIMS and synchrotron radiation diffraction. A duplex structure with an outer TiO{sub 2}-rich layer and an inner mixed layer of SiO{sub 2} and TiO{sub 2} was observed. Results of NMR and TEM verified for the first time the direct evidence of amorphous silica formation during the oxidation of Ti{sub 3}SiC{sub 2} at the temperature range 500-1000 C.

  10. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray...

  11. News Item

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

    and NCEM Staff Gather to Identify Scientific Synergies The Molecular Foundry and NCEM staff participated in a Scientific Retreat on November 4-5 - formerly the dates of our joint Annual User Meeting that was canceled due to the government shutdown - to discuss new scientific opportunities in nanoscience and electron scattering that are of interest to the two centers. The retreat focused on the ways that the scientific achievements of the Molecular Foundry and NCEM benefit from increasingly close

  12. Evaluation of stacking faults and associated partial dislocations in AlSb/GaAs (001) interface by aberration-corrected high-resolution transmission electron microscopy

    SciTech Connect (OSTI)

    Wen, C.; Ge, B. H.; Cui, Y. X.; Li, F. H.; Zhu, J.; Yu, R.; Cheng, Z. Y.

    2014-11-15

    The stacking faults (SFs) in an AlSb/GaAs (001) interface were investigated using a 300 kV spherical aberration-corrected high-resolution transmission electron microscope (HRTEM). The structure and strain distribution of the single and intersecting (V-shaped) SFs associated with partial dislocations (PDs) were characterized by the [110] HRTEM images and geometric phase analysis, respectively. In the biaxial strain maps ?{sub xx} and ?{sub yy}, a SF can be divided into several sections under different strain states (positive or negative strain values). Furthermore, the strain state for the same section of a SF is in contrast to each other in ?{sub xx} and ?{sub yy} strain maps. The modification in the strain states was attributed to the variation in the local atomic displacements for the SF in the AlSb film on the GaAs substrate recorded in the lattice image. Finally, the single SF was found to be bounded by two 30 PDs. A pair of 30 PDs near the heteroepitaxial interface reacted to form a Lomer-Cottrell sessile dislocation located at the vertices of V-shaped SFs with opposite screw components. The roles of misfit dislocations, such as the PDs, in strain relaxation were also discussed.

  13. Chemical Imaging Analysis of Environmental Particles Using the Focused Ion Beam/Scanning Electron Microscopy Technique: Microanalysis Insights into Atmospheric Chemistry of Fly Ash

    SciTech Connect (OSTI)

    Chen, Haihan; Grassian, Vicki H.; Saraf, Laxmikant V.; Laskin, Alexander

    2013-01-21

    Airborne fly ash from coal combustion may represent a source of bioavailable iron (Fe) in the open ocean. However, few studies have been made focusing on Fe speciation and distribution in coal fly ash. In this study, chemical imaging of fly ash has been performed using a dual-beam FIB/SEM (focused ion beam/scanning electron microscope) system for a better understanding of how simulated atmospheric processing modify the morphology, chemical compositions and element distributions of individual particles. A novel approach has been applied for cross-sectioning of fly ash specimen with a FIB in order to explore element distribution within the interior of individual particles. Our results indicate that simulated atmospheric processing causes disintegration of aluminosilicate glass, a dominant material in fly ash particles. Aluminosilicate-phase Fe in the inner core of fly ash particles is more easily mobilized compared with oxide-phase Fe present as surface aggregates on fly ash spheres. Fe release behavior depends strongly on Fe speciation in aerosol particles. The approach for preparation of cross-sectioned specimen described here opens new opportunities for particle microanalysis, particular with respect to inorganic refractive materials like fly ash and mineral dust.

  14. Optoacoustic Microscopy for Investigation of MaterialNanostructures...

    Office of Scientific and Technical Information (OSTI)

    be used for quantitative imaging of nanoscale material features - including features that may be buried so as to be inaccessible to conventional lightwave or electron microscopies. ...

  15. Fine precipitation scenarios of AlZnMg(Cu) alloys revealed by advanced atomic-resolution electron microscopy study Part II: Fine precipitation scenarios in AlZnMg(Cu) alloys

    SciTech Connect (OSTI)

    Liu, J.Z.; Chen, J.H.; Liu, Z.R.; Wu, C.L.

    2015-01-15

    Although they are among the most important precipitation-hardened materials for industry applications, the high-strength AlZnMg(Cu) alloys have thus far not yet been understood adequately about their underlying precipitation scenarios in relation with the properties. This is partly due to the fact that the structures of a number of different precipitates involved in the alloys are unknown, and partly due to the complexity that the precipitation behaviors of the alloys may be closely related to the alloy's composition. In Part I of the present study, we have determined all the unknown precipitate structures in the alloys. Here in Part II, using atomic-resolution electron microscopy in association with the first principles energy calculations, we further studied and correlated the phase/structure transformation/evolution among these hardening precipitates in relation with the alloy's composition. It is shown that there are actually two coexisting classes of hardening precipitates in these alloys: the first class includes the η′-precipitates and their early-stage Guinier–Preston (GP-η′) zones; the second class includes the precursors of the equilibrium η-phase (referred to η{sub p}, or η-precursor) and their early-stage Guinier–Preston (GP-η{sub p}) zones. The two coexisting classes of precipitates correspond to two precipitation scenarios. - Highlights: • We determine and verify all the key precipitate structures in AlMgZn(Cu) alloys. • We employ aberration-corrected scanning transmission electron microscopy (STEM). • We use aberration-corrected high-resolution TEM (HRTEM) for the investigations. • We obtain atomic-resolution images of the precipitates and model their structures. • We refine all precipitate structures with quantitative image simulation analysis. • The hardening precipitates in AlZnMg alloys shall be classified into two groups. • Two precipitation scenarios coexist in the alloys. • The precipitation behavior of such an

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

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

    oxidation of light paraffins and olefins, as well as the partial oxidation of methanol. We present HAADF-STEM investigations of various complex oxide phases and show that...

  17. High resolution transmission electron microscopy of aluminophosphates

    SciTech Connect (OSTI)

    Ulan, J.G.; Gronsky, R. ); Szostak, R. ); Sorby, K. . Dept. of Chemistry)

    1990-04-01

    VPI-5 transforms to AlPO{sub 4}-8 under mild thermal treatment (100{degree}C, 18 hrs). HRTEM micrographs, oriented normal to the c axis, show extensive defect-free regions in VPI-5, while slip planes normal to the c axis are found in AlPO{sub 4}-8. Analysis of the HRTEM data, in conjunction with infrared and thermal analysis, adsorption studies and x-ray powder diffraction, has lead to a proposed structure for AlPO{sub 4}-8. Though the sheets containing the 18 member rings which define the pores in VPI-5 remain intact in AlPO{sub 4}-8, reduction in the porosity is attributed to blockages created by the movement of these sheets relative to each other. 8 refs., 7 figs.

  18. Diamondoid Monolayers as Monochromatic Electron Source

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

    Scientific applications also stand to benefit greatly, such as electron-beam lithography, electron microscopy, and next-generation free-electron lasers. Diamondoids are molecular ...

  19. News Item

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

    In Memoriam: Gareth Thomas (1932-2014) Gareth Thomas, founder of Berkeley Lab's National Center for Electron Microscopy (NCEM) and one of the world's foremost experts on electron microscopy, passed away on February 7. He was 81. A native of Wales, Thomas earned his Ph.D. in metallurgy from Cambridge University, and joined the UC Berkeley (UCB) faculty in 1960. He became a UCB professor of metallurgy and a faculty scientist at Berkeley Lab, then known as Lawrence Berkeley Lab (LBL), in 1966. At a

  20. Photothermal imaging scanning microscopy

    DOE Patents [OSTI]

    Chinn, Diane; Stolz, Christopher J.; Wu, Zhouling; Huber, Robert; Weinzapfel, Carolyn

    2006-07-11

    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.

  1. Nonlinear vibrational microscopy

    DOE Patents [OSTI]

    Holtom, Gary R.; Xie, Xiaoliang Sunney; Zumbusch, Andreas

    2000-01-01

    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. Analytical Microscopy. National Renewable Energy Laboratory (NREL) Measurements and Charactization (Fact Sheet).

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

    MAJOR INSTRUMENTATION FOR TRANSMISSION ELECTRON MICROSCOPY Special Features Lateral Resolution Typical Applications Analytical Technique System FEI F20 (UT) Phillips CM30 Transmission electron microscopy Structural and compositional analysis and lattice imaging 0.23 nm High-resolution, EDS Field-emission scanning transmission electron microscopy Structural, electronic, and compositional analysis; elemental mapping; lattice imaging 0.19 nm for HRTEM; 0.14 nm for Z-contrast STEM High-resolution,

  3. 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 is powerful in that it can probe large volumes of material at high spatial resolution with exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics.

  4. Orientation imaging microscopy of polycrystalline sodium chloride

    SciTech Connect (OSTI)

    Staiger, M.P.; Kolbeinsson, I.; Newman, J.; Woodfield, T.; Sato, T.

    2010-04-15

    A novel preparation technique is described that makes possible grain size analysis of polycrystalline NaCl using orientation imaging microscopy via electron backscatter diffraction (EBSD). The preparation methodology is specifically developed to overcome difficulties in preparing microporous NaCl for microscopy. The grain size and crystallographic texture of polycrystalline NaCl samples, prepared via solution pressure and sintered in the range of 650-780 deg. C, were able to be measured successfully with EBSD. The limitations of the preparation technique for EBSD analysis of NaCl are also discussed.

  5. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with...

  6. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

  7. Biological Imaging by Soft X-Ray Diffraction Microscopy

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

    Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in ...

  8. Local Imaging of High Mobility Two-Dimensional Electron Systems...

    Office of Scientific and Technical Information (OSTI)

    Tunneling Microscopy Citation Details In-Document Search Title: Local Imaging of High Mobility Two-Dimensional Electron Systems with Virtual Scanning Tunneling Microscopy You ...

  9. Fourier plane imaging microscopy

    SciTech Connect (OSTI)

    Dominguez, Daniel Peralta, Luis Grave de; Alharbi, Nouf; Alhusain, Mdhaoui; Bernussi, Ayrton A.

    2014-09-14

    We show how the image of an unresolved photonic crystal can be reconstructed using a single Fourier plane (FP) image obtained with a second camera that was added to a traditional compound microscope. We discuss how Fourier plane imaging microscopy is an application of a remarkable property of the obtained FP images: they contain more information about the photonic crystals than the images recorded by the camera commonly placed at the real plane of the microscope. We argue that the experimental results support the hypothesis that surface waves, contributing to enhanced resolution abilities, were optically excited in the studied photonic crystals.

  10. Molecular Foundry

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

    See the Foundry's full equipment list Research Themes Discovering the Future, Atom by Atom The six-story, 94,000 square-foot Molecular Foundry building at LBNL overlooks the UC Berkeley campus and, from a distance, the San Francisco Bay. Directly adjacent to the Foundry is the NCEM complex that was established in 1983 to maintain a forefront research center for electron microscopy with state-of-the-art instrumentation and expertise. Merged with the Molecular Foundry in 2014 to take advantage of

  11. Using real-time electron microscopy to explore the effects of transition-metal composition on the local thermal stability in charged LixNiyMnzCo1-y-zO2 cathode materials

    SciTech Connect (OSTI)

    Hwang, Sooyeon; Kim, Seung Min; Bak, Seong -Min; Kim, Se Young; Cho, Byung -Won; Chung, Kyung Yoon; Lee, Jeong Yong; Stach, Eric A.; Chang, Wonyoung

    2015-05-08

    In this study, we use in-situ transmission electron microcopy (TEM) to investigate the thermal decomposition that occurs at the surface of charged LixNiyMnzCo1-y-zO2 (NMC) cathode materials of different composition (with y, z=0.8, 0.1 and 0.6, 0.2 and 0.4, 0.3), after they have been charged to their practical upper limit voltage (4.3V). By heating these materials inside the TEM, we are able to directly characterize near surface changes in both their electronic structure (using electron energy loss spectroscopy) and crystal structure and morphology (using electron diffraction and bright-field imaging). The most Ni-rich material (y, z = 0.8, 0.1) is found to be thermally unstable at significantly lower temperatures than the other compositions – this is manifested by changes in both the electronic structure and the onset of phase transitions at temperatures as low as 100°C. Electron energy loss spectroscopy indicates that the thermally induced reduction of Ni ions drives these changes, and that this is exacerbated by the presence of an additional redox reaction that occurs at 4.2V in the y, z = 0.8, 0.1 material. Exploration of individual particles shows that there are substantial variations in the onset temperatures and overall extent of these changes. Of the compositions studied, the composition of y, z = 0.6, 0.2 has the optimal combination of high energy density and reasonable thermal stability. The observations herein demonstrate that real time electron microscopy provide direct insight into the changes that occur in cathode materials with temperature, allowing optimization of different alloy concentrations to maximize overall performance.

  12. Using real-time electron microscopy to explore the effects of transition-metal composition on the local thermal stability in charged LixNiyMnzCo1-y-zO2 cathode materials

    SciTech Connect (OSTI)

    Hwang, Sooyeon; Kim, Seung Min; Bak, Seong -Min; Kim, Se Young; Cho, Byung -Won; Chung, Kyung Yoon; Lee, Jeong Yong; Stach, Eric A.; Chang, Wonyoung

    2015-05-08

    In this study, we use in-situ transmission electron microcopy (TEM) to investigate the thermal decomposition that occurs at the surface of charged LixNiyMnzCo1-y-zO2 (NMC) cathode materials of different composition (with y, z=0.8, 0.1 and 0.6, 0.2 and 0.4, 0.3), after they have been charged to their practical upper limit voltage (4.3V). By heating these materials inside the TEM, we are able to directly characterize near surface changes in both their electronic structure (using electron energy loss spectroscopy) and crystal structure and morphology (using electron diffraction and bright-field imaging). The most Ni-rich material (y, z = 0.8, 0.1) is found to be thermally unstable at significantly lower temperatures than the other compositions this is manifested by changes in both the electronic structure and the onset of phase transitions at temperatures as low as 100C. Electron energy loss spectroscopy indicates that the thermally induced reduction of Ni ions drives these changes, and that this is exacerbated by the presence of an additional redox reaction that occurs at 4.2V in the y, z = 0.8, 0.1 material. Exploration of individual particles shows that there are substantial variations in the onset temperatures and overall extent of these changes. Of the compositions studied, the composition of y, z = 0.6, 0.2 has the optimal combination of high energy density and reasonable thermal stability. The observations herein demonstrate that real time electron microscopy provide direct insight into the changes that occur in cathode materials with temperature, allowing optimization of different alloy concentrations to maximize overall performance.

  13. Microscopy of photoionisation processes

    SciTech Connect (OSTI)

    Aseyev, S A; Mironov, B N; Minogin, V G; Cherkun, Aleksandr P; Chekalin, Sergei V

    2013-04-30

    A method is demonstrated which combines the ionisation of free molecules by a sharply focused femtosecond laser beam and projection microscopy in a divergent electric field. The electric field is produced in vacuum between a metallic tip and a flat positionsensitive charged particle detector. The method enables investigation of photoionisation processes in low-density gases with a subdiffraction spatial resolution and can be used as well in profile measurements for sharply focused, intense laser beams. In a demonstration experiment, a femtosecond laser beam with a peak intensity of {approx}10{sup 14} W cm{sup -2} was focused to a 40-{mu}m-diameter waist in vacuum near a millimetre-size tip and {approx}2-{mu}m spatial resolution was achieved. According to our estimates, the use of a sharper tip will ensure a submicron spatial resolution, which is a crucial condition for the spatial diagnostics of sharply focused short-wavelength VUV radiation and X-rays. (extreme light fields and their applications)

  14. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

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

    1995-05-16

    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.

  15. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

    Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

    1995-01-01

    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.

  16. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  17. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  18. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  19. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  20. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  1. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

  2. 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 exquisite chemical, electronic, and bond orientation contrast. The development of diffraction-based methods such as ptychography has, in principle, removed the resolution limit imposed by the characteristics of the x-ray optics. Using soft x-ray ptychography, researchers at the ALS have demonstrated the highest-resolution

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

    SciTech Connect (OSTI)

    Lai, Shen; Kyu Jang, Sung; Jae Song, Young; Lee, Sungjoo

    2014-01-27

    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.

  4. Electron Transport at the Nanoscale Spatially Revealed by Four...

    Office of Scientific and Technical Information (OSTI)

    Electron Transport at the Nanoscale Spatially Revealed by Four-Probe Scanning Tunneling Microscopy Citation Details In-Document Search Title: Electron Transport at the Nanoscale ...

  5. Digital field ion microscopy

    SciTech Connect (OSTI)

    Sijbrandij, S.J.; Russell, K.F.; Miller, M.K.; Thomson, R.C.

    1998-01-01

    Due to environmental concerns, there is a trend to avoid the use of chemicals needed to develop negatives and to process photographic paper, and to use digital technologies instead. Digital technology also offers the advantages that it is convenient, as it enables quick access to the end result, allows image storage and processing on computer, allows rapid hard copy output, and simplifies electronic publishing. Recently significant improvements have been made to the performance and cost of camera-sensors and printers. In this paper, field ion images recorded with two digital cameras of different resolution are compared to images recorded on standard 35 mm negative film. It should be noted that field ion images exhibit low light intensity and high contrast. Field ion images were recorded from a standard microchannel plate and a phosphor screen and had acceptance angles of {approximately} 60{degree}. Digital recordings were made with a Digital Vision Technologies (DVT) MICAM VHR1000 camera with a resolution of 752 x 582 pixels, and a Kodak DCS 460 digital camera with a resolution of 3,060 x 2,036 pixels. Film based recordings were made with Kodak T-MAX film rated at 400 ASA. The resolving power of T-MAX film, as specified by Kodak, is between 50 and 125 lines per mm, which corresponds to between 1,778 x 1,181 and 4,445 x 2,953 pixels, i.e. similar to that from the DCS 460 camera. The intensities of the images were sufficient to be recorded with standard fl:1.2 lenses with exposure times of less than 2 s. Many digital cameras were excluded from these experiments due to their lack of sensitivity or the inability to record a full frame image due to the fixed working distance defined by the vacuum system. The digital images were output on a Kodak Digital Science 8650 PS dye sublimation color printer (300 dpi). All field ion micrographs presented were obtained from a Ni-Al-Be specimen.

  6. Visualizing Individual Carbon Nanotubes with Optical Microscopy...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Visualizing Individual Carbon Nanotubes with Optical Microscopy Title: Visualizing Individual Carbon Nanotubes with Optical Microscopy Authors: Novak, Michael A. ...

  7. Reflected beam illumination microscopy using a microfluidics...

    Office of Scientific and Technical Information (OSTI)

    Reflected beam illumination microscopy using a microfluidics device - progress report 6152014. Citation Details In-Document Search Title: Reflected beam illumination microscopy ...

  8. Combined frequency modulated atomic force microscopy and scanning tunneling microscopy detection for multi-tip scanning probe microscopy applications

    SciTech Connect (OSTI)

    Morawski, Ireneusz; Spiegelberg, Richard; Korte, Stefan; Voigtländer, Bert

    2015-12-15

    A method which allows scanning tunneling microscopy (STM) tip biasing independent of the sample bias during frequency modulated atomic force microscopy (AFM) operation is presented. The AFM sensor is supplied by an electronic circuit combining both a frequency shift signal and a tunneling current signal by means of an inductive coupling. This solution enables a control of the tip potential independent of the sample potential. Individual tip biasing is specifically important in order to implement multi-tip STM/AFM applications. An extensional quartz sensor (needle sensor) with a conductive tip is applied to record simultaneously topography and conductivity of the sample. The high resonance frequency of the needle sensor (1 MHz) allows scanning of a large area of the surface being investigated in a reasonably short time. A recipe for the amplitude calibration which is based only on the frequency shift signal and does not require the tip being in contact is presented. Additionally, we show spectral measurements of the mechanical vibration noise of the scanning system used in the investigations.

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

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  10. Ultra-High Resolution Electron Microscopy for Catalyst Characterization

    Broader source: Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.