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1

High Temperature Superconductors  

Science Journals Connector (OSTI)

Abstract A brief review of the phenomenology of superconductivity, the distinction between type I and type II superconductors, and the application of type II superconductors is followed by a history of the theory of conventional superconductivity. Unconventional high-temperature superconductivity in the copper oxides is reviewed as a phenomenon occurring in narrow two-dimensional bands where the time for an electron transfer between like atoms is comparable to the period of an optical-mode lattice vibration. A family of iron pnictides containing layers of iron atoms may not require an alternative explanation of its high-temperature superconductivity.

J.B. Goodenough

2013-01-01T23:59:59.000Z

2

Electrochemical investigations of various high-temperature superconductor phases  

Science Journals Connector (OSTI)

Electrochemical investigations of various high-temperature superconductor phases ... Electrochemistry of High-Temperature Superconductors ...

David R. Riley; A. Manthiram; John T. McDevitt

1992-11-01T23:59:59.000Z

3

High temperature superconductor current leads  

DOE Patents (OSTI)

An electrical lead is disclosed having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths. 9 figs.

Hull, J.R.; Poeppel, R.B.

1995-06-20T23:59:59.000Z

4

Hole doping in high temperature superconductors using the XANES technique  

E-Print Network (OSTI)

Hole doping in high temperature superconductors using the1994 Thallium-Based High Temperature Superconductors ed A M1994 Thallium-Based High Temperature Superconductors ed A M

Hamdan, Nasser

2012-01-01T23:59:59.000Z

5

QED3 Theory of High Temperature Superconductors  

E-Print Network (OSTI)

QED3 Theory of High Temperature Superconductors Zlatko Tesanovi´c The Johns Hopkins University is The Problem in high Tc superconductors? · Superconducting state appears dx2-y2 "BCS-like". Low energy: · Today, everything seems to be a high temperature superconduc- tor (cuprates, C60's, MgB2

Tesanovic, Zlatko

6

Metallic Hydrogen: A High-Temperature Superconductor?  

Science Journals Connector (OSTI)

Application of the BCS theory to the proposed metallic modification of hydrogen suggests that it will be a high-temperature superconductor. This prediction has interesting astrophysical consequences, as well as implications for the possible development of a superconductor for use at elevated temperatures.

N. W. Ashcroft

1968-12-23T23:59:59.000Z

7

Long, Highly-Ordered High-Temperature Superconductor Nanowire Arrays  

Science Journals Connector (OSTI)

Long, Highly-Ordered High-Temperature Superconductor Nanowire Arrays ... For bulk superconductors, the electrical resistance drops precipitously to zero below the superconducting transition temperature (Tc). ... Even these temperatures are considerably higher than those found in conventional superconductor NWs of similar widths, which are typically below liquid helium temperature (4.2 K). ...

Ke Xu; James R. Heath

2008-10-28T23:59:59.000Z

8

Charged Vortices in High Temperature Superconductors  

Science Journals Connector (OSTI)

It is argued that in the mixed state of a type II superconductor, because of the difference of the chemical potential in a superconducting versus normal state, the vortex cores may become charged. The extra electron density is estimated. The extra charge contributes to the dynamics of the vortices; in particular, it can explain in certain cases the change of the sign of the Hall coefficient below Tc frequently observed in the high temperature superconductors.

D. I. Khomskii and A. Freimuth

1995-08-14T23:59:59.000Z

9

High temperature crystalline superconductors from crystallized glasses  

DOE Patents (OSTI)

A method of preparing a high temperature superconductor from an amorphous phase. The method involves preparing a starting material of a composition of Bi.sub.2 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ox or Bi.sub.2 Sr.sub.2 Ca.sub.4 Cu.sub.5 Ox, forming an amorphous phase of the composition and heat treating the amorphous phase for particular time and temperature ranges to achieve a single phase high temperature superconductor.

Shi, Donglu (Downers Grove, IL)

1992-01-01T23:59:59.000Z

10

Electron-Phonon Coupling in High-Temperature Cuprate Superconductors as Revealed by Angle-resolved Photoemisson Spectroscopy  

E-Print Network (OSTI)

Cuprate oxide high-temperature superconductors are dopedsuperconductivity. High temperature superconductors arein understanding high-temperature superconductors, such as

Zhou, X.J.; Hussain, Z.; Shen, Z.-X.

2005-01-01T23:59:59.000Z

11

An unusual isotope effect in a high-transition-temperature superconductor  

E-Print Network (OSTI)

coupling in high-temperature superconductors. Nature 412,Properties of High Temperature Superconductors IV (ed.in a high-transition-temperature superconductor G. -H. Gweon

2004-01-01T23:59:59.000Z

12

To Crack or Not to Crack: Strain in High Temperature Superconductors  

E-Print Network (OSTI)

Strain in High Temperature Superconductors Arno GodekeCrack: Strain in High Temperature Superconductors MotivationCrack: Strain in High Temperature Superconductors How do Nb

Godeke, Arno

2008-01-01T23:59:59.000Z

13

X-ray diffuse scattering studies of the local structural inhomogeneities in high temperature superconductors  

E-Print Network (OSTI)

in high temperature superconductors A dissertation submittedChemistry of High-Temperature Superconductors. Word Scienti?work on the high temperature superconductors, one of the

Liu, Xuerong

2009-01-01T23:59:59.000Z

14

Correlated electrons in high-temperature superconductors Elbio Dagotto  

E-Print Network (OSTI)

Correlated electrons in high-temperature superconductors Elbio Dagotto Department of Physics Theoretical ideas and experimental results concerning high-temperature superconductors are reviewed. Special, National High Magnetic Field Laboratory, and MAR TECH, Florida State University, Tallahassee, Florida 32308

Wu, Zhigang

15

3 - High temperature superconductor (HTS) cables  

Science Journals Connector (OSTI)

Abstract: Many superconductor applications such as rotating machinery, transformers and magnets with low inductance require high current cables with low AC losses. This chapter gives an overview on cabling techniques for the high temperature superconductors (HTS) BSCCO (2212), BSCCO (2223) and (RE)BCO. A short review is given of the basic properties of HTS wires and tapes and the basic requirements of HTS cables for different applications. Cabling concepts for the different HTS materials are presented, and current performance and AC loss behaviour are discussed. After a short description of remaining challenges and future trends, cabling techniques are summarized.

S.I. Schlachter; W. Goldacker

2012-01-01T23:59:59.000Z

16

Motor Using High Temperature Superconductor as a Rotor  

Science Journals Connector (OSTI)

It is found that a high temperature superconductor rotates in the rotating magnetic field at ... authors and a small motor is made using high temperature superconductor as a rotor. This motor rotates at...

Makoto Takenaka; Masaharu Minami; Kazuo Morimoto

1994-01-01T23:59:59.000Z

17

ANALYSIS OF FUTURE PRICES AND MARKETS FOR HIGH TEMPERATURE SUPERCONDUCTORS  

E-Print Network (OSTI)

1 ANALYSIS OF FUTURE PRICES AND MARKETS FOR HIGH TEMPERATURE SUPERCONDUCTORS BY JOSEPH MULHOLLAND of Future Prices and Markets for High Temperature Superconductors 2 I . PURPOSE, SCOPE AND APPROACH analysts to make estimates about the future of high temperature superconductor (HTS) technology

18

Impurity effects on electronmode coupling in high-temperature superconductors  

E-Print Network (OSTI)

LETTERS Impurity effects on electron­mode coupling in high-temperature superconductors K. TERASHIMA espite years of intensive research on copper oxide superconductors with high transition temperatures (Tc in the high-Tc superconductors. The interaction of electrons with bosonic excitations (phonons or spin

Loss, Daniel

19

Application of high temperature superconductors for fusion  

Science Journals Connector (OSTI)

The use of High Temperature Superconductor (HTS) materials in future fusion machines can increase the efficiency drastically. For ITER, W7-X and JT-60SA the economic benefit of HTS current leads was recognized after a 70kA HTS current lead demonstrator was designed, fabricated and successfully tested by Karlsruhe Institute of Technology (KIT, which is a merge of former Forschungszentrum Karlsruhe and University of Karlsruhe). For ITER, the Chinese Domestic Agency will provide the current leads as a part of the superconducting feeder system. KIT is in charge of design, construction and test of HTS current leads for W7-X and JT-60SA. For W7-X 14 current leads with a maximum current of 18.2kA are required that are oriented with the room temperature end at the bottom. JT60-SA will need 26 current leads (20 leads @ 20kA and 6 leads @ 25.7kA) which are mounted in vertical, normal position. These current leads are based on BiSCCO HTS superconductors, demonstrating that HTS material is now state of the art for highly efficient current leads. With respect to future fusion reactors, it would be very promising to use HTS material not only in current leads but also in coils. This would allow a large increase of efficiency if the coils could be operated at temperatures ?65K. With such a high temperature it would be possible to omit the radiation shield of the coils, resulting in a less complex cryostat and a size reduction of the machine. In addition less refrigeration power is needed saving investment and operating costs. However, to come to an HTS fusion coil it is necessary to develop low ac loss HTS cables for currents well above 20kA at high fields well above 10T. The high field rules BiSCCO superconductors out at temperatures above 50K, but RE-123 superconductors are promising. The development of a high current, high field RE-123 HTS fusion cable will not be targeted outside fusion community and has to be in the frame of a long term development programme for DEMO. KIT has already demonstrated a scalable concept using RE-123 HTS tapes that are assembled to Roebel type conductors. This concept can be expanded to form Rutherford cables as starting point for a development of a high current fusion cable. The status and prospect of using HTS conductors for fusion is discussed.

W.H. Fietz; R. Heller; S.I. Schlachter; W. Goldacker

2011-01-01T23:59:59.000Z

20

Thermomagnetic phenomena in the mixed state of high temperature superconductors  

SciTech Connect

Galvano- and thermomagnetic-phenomena in high temperature superconductors, based on kinetic coefficients, are discussed, along with a connection between the electric field and the heat flow in superconductor mixed state. The relationship that determines the transport coefficients of high temperature superconductors in the mixed state based on Seebeck and Nernst effects is developed. It is shown that this relationship is true for a whole transition region of the resistive mixed state of a superconductor. Peltier, Ettingshausen and Righi-Leduc effects associated with heat conductivity as related to high temperature superconductors are also addressed.

Meilikhov, E.Z.

1995-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Flux noise in high-temperature superconductors  

Science Journals Connector (OSTI)

Spontaneously created vortex-antivortex pairs are the predominant source of flux noise in high-temperature superconductors. In principle, flux noise measurements allow to check theoretical predictions for both the distribution of vortex-pair sizes and for the vortex diffusivity. In this paper the flux-noise power spectrum is calculated for the highly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8+?, both for bulk crystals and for ultrathin films. The spectrum is basically given by the Fourier transform of the temporal magnetic-field correlation function. We start from a Berezinskii-Kosterlitz-Thouless-type theory and incorporate vortex diffusion, intrapair vortex interaction, and annihilation of pairs by means of a Fokker-Planck equation to determine the noise spectrum below and above the superconducting transition temperature. We find white noise at low frequencies ? and a spectrum proportional to 1/?3/2 at high frequencies. The crossover frequency between these regimes strongly depends on temperature. The results are compared with earlier results of computer simulations.

Carsten Timm

1997-02-01T23:59:59.000Z

22

Sealed glass coating of high temperature ceramic superconductors  

DOE Patents (OSTI)

A method and article of manufacture of a lead oxide based glass coating on a high temperature superconductor. The method includes preparing a dispersion of glass powders in a solution, applying the dispersion to the superconductor, drying the dispersion before applying another coating and heating the glass powder dispersion at temperatures below oxygen diffusion onset and above the glass melting point to form a continuous glass coating on the superconductor to establish compressive stresses which enhance the fracture strength of the superconductor.

Wu, Weite (Tainan, TW); Chu, Cha Y. (Garnerville, NY); Goretta, Kenneth C. (Downers Grove, IL); Routbort, Jules L. (Darien, IL)

1995-01-01T23:59:59.000Z

23

Fermi liquid theory for high temperature superconductors  

SciTech Connect

In this article the Fermi liquid theory of metals is discussed starting from Luttinger's theorem. The content of Luttinger's Theorem and its implications for microscopic theories of high temperature superconductors are discussed. A simple quasi-2d Fermi liquid theory is introduced and some of its properties are calculated. It is argued that a number of experiments on YBa/sub 2/Cu/sub 3/O/sub 6+x/, x > 0.5, strongly suggest the existence of a Fermi surface and thereby a Fermi liquid normal state. 25 refs., 1 fig.

Bedell, K.S.

1988-01-01T23:59:59.000Z

24

Boson linewidth in high-temperature superconductors  

Science Journals Connector (OSTI)

We have considered boson exchange models of high-temperature superconductors which use Eliashberg theory and in which the bare bosons have sharp spectral features. In particular, we have calculated the boson linewidth due to the interaction with the charge carriers. We find for a recent model of Arnold, Mueller, and Swihart that the width of the 10-meV peak in their ?2F is consistent with a broadened boson peak. However, for a weak-coupling model with the boson peak in the eV range, the interaction causes a broadening in the boson peak that is comparable to or larger than the energy of the peak.

James C. Swihart; William H. Butler; Fred M. Mueller; Gerald B. Arnold

1992-09-01T23:59:59.000Z

25

Applications of bulk high-temperature superconductors  

SciTech Connect

The development of high-temperature superconductors (HTSs) can be broadly generalized into thin-film electronics, wire applications, and bulk applications. We consider bulk HTSs to include sintered or crystallized forms that do not take the geometry of filaments or tapes, and we discuss major applications for these materials. For the most part applications may be realized with the HTSs cooled to 77 K, and the properties of the bulk HTSs are often already sufficient for commercial use. A non-exhaustive list of applications for bulk HTSs includes trapped field magnets, hysteresis motors, magnetic shielding, current leads, and magnetic bearings. These applications are briefly discussed in this paper.

Hull, J.R.

1995-06-01T23:59:59.000Z

26

Vibrational Raman Spectroscopy of High-temperature Superconductors  

E-Print Network (OSTI)

Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering Wiley & Sons Ltd, Chichester, 2002 #12;Vibrational Raman Spectroscopy of High-temperature

Nabben, Reinhard

27

High Temperature Superconductor Cable Concepts for Fusion Magnets.  

E-Print Network (OSTI)

??Three concepts of high temperature superconductor cables carrying kA currents (RACC, CORC and TSTC) are investigated, optimized and evaluated in the scope of their applicability (more)

Barth, Christian

2013-01-01T23:59:59.000Z

28

Development of Strengthened Bundle High Temperature Superconductors  

SciTech Connect

In the process of developing high temperature superconducting (HTS) transmission cables, it was found that mechanical strength of the superconducting tape is the most crucial property that needs to be improved. It is also desirable to increase the current carrying capacity of the conductor so that fewer layers are needed to make the kilo-amp class cables required for electric utility usage. A process has been developed by encapsulating a stack of Bi-2223/Ag tapes with a silver or non-silver sheath to form a strengthened bundle superconductor. This process was applied to HTS tapes made by the Continuous Tube Forming and Filling (CTFF) technique pursued by Plastronic Inc. and HTS tapes obtained from other manufacturers. Conductors with a bundle of 2 to 6 HTS tapes have been made. The bundled conductor is greatly strengthened by the non-silver sheath. No superconductor degradation as compared to the sum of the original critical currents of the individual tapes was seen on the finished conductors.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Demko, J.A. [Oak Ridge Inst. for Science and Education, TN (United States); Tomsic, M. [Plastronic, Inc., Troy, OH (United States); Sinha, U. [Southwire Company, Carollton, GA (United States)

1997-12-31T23:59:59.000Z

29

Contact resistance measurements recorded at conductive polymer/high-temperature superconductor interfaces  

Science Journals Connector (OSTI)

Contact resistance measurements recorded at conductive polymer/high-temperature superconductor interfaces ... Structure of the Electrical Double Layer in High-Temperature Superconductors. ...

Steven G. Haupt; David R. Riley; Jianai Zhao; John T. McDevitt

1993-01-01T23:59:59.000Z

30

Sealed glass coating of high temperature ceramic superconductors  

DOE Patents (OSTI)

A method and article of manufacture of a lead oxide based glass coating on a high temperature superconductor is disclosed. The method includes preparing a dispersion of glass powders in a solution, applying the dispersion to the superconductor, drying the dispersion before applying another coating and heating the glass powder dispersion at temperatures below oxygen diffusion onset and above the glass melting point to form a continuous glass coating on the superconductor to establish compressive stresses which enhance the fracture strength of the superconductor. 8 figs.

Wu, W.; Chu, C.Y.; Goretta, K.C.; Routbort, J.L.

1995-05-02T23:59:59.000Z

31

4 - Bulk high temperature superconductor (HTS) materials  

Science Journals Connector (OSTI)

Abstract: This chapter concentrates on bulk materials. A bulk superconductor is one in which the superconductor has been formed into a lump, usually cylindrically shaped, but can also be hexagonal, rectangular or even square. Bulk superconductors are typically 35cm across and 1cm thick. They have many uses but the principal one is as extremely compact high-field permanent magnets in superconducting machines. A 2.6cm (RE)BCO puck has been magnetised to 17.24 T: this is an order of magnitude greater than the flux density available from a conventional permanent magnet. This chapter describes the materials, manufacturing process, magnetisation process and some examples of machines.

T. Coombs

2012-01-01T23:59:59.000Z

32

Scaling in high-temperature superconductors  

Science Journals Connector (OSTI)

A Hartree approximation is used to study the interplay of two kinds of scaling which arise in high-temperature superconductors, namely critical-point scaling and that due to the confinement of electron pairs to their lowest Landau level in the presence of an applied magnetic field. In the neighborhood of the zero-field critical point, thermodynamic functions scale with the scaling variable [T-Tc2(B)]/B1/2?, which differs from the variable [T-Tc(0)]/B1/2? suggested by the Gaussian approximation. Lowest-Landau-level (LLL) scaling occurs in a region of high field surrounding the upper critical-field line but not in the vicinity of the zero-field transition. For YBa2Cu3O7-? in particular, a field of at least 10 T is needed to observe LLL scaling. These results are consistent with a range of recent experimental measurements of the magnetization, transport properties, and, especially, the specific heat of high-Tc materials.

Ian D. Lawrie

1994-10-01T23:59:59.000Z

33

Cryocooler Applications for High-Temperature Superconductor Magnetic Bearings  

Science Journals Connector (OSTI)

The efficiency and stability of rotational magnetic suspension systems are enhanced by the use of high-temperature superconductor (HTS) magnetic bearings. Fundamental aspects of ... aspects to be considered are i...

R. C. Niemann; J. R. Hull

2002-01-01T23:59:59.000Z

34

Growth of high-temperature superconductor crystals from flux  

Science Journals Connector (OSTI)

Crystallization of high-temperature superconductors was studied in La-Sr-Cu-O,...2Cu3O6.5+x were obtained by spontaneous crystallization from homogeneous nonstoichiometric melts enriched in bariu...

L N Demianets; A B Bykov; O K Melnikov; S M Stishov

1991-04-01T23:59:59.000Z

35

Engineering Design of A High-Temperature Superconductor Current Lead  

Science Journals Connector (OSTI)

As part of the U.S. Department of Energys Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suita...

R. C. Niemann; Y. S. Cha; J. R. Hull; M. A. Daugherty; W. E. Buckles

1994-01-01T23:59:59.000Z

36

Experimental demonstration of vortex pancake in high temperature superconductor  

Science Journals Connector (OSTI)

In order to demonstrate the existence of the vortex pancake in high temperature superconductor experimentally, a configuration in which the current...E-j relation obtained with this electrodes spatial configurati...

Wei-xian Wang; Yu-heng Zhang

2006-09-01T23:59:59.000Z

37

High-temperature superconductor applications development at Argonne National Laboratory  

SciTech Connect

Developments at Argonne National Laboratory of near and intermediate term applications using high-temperature superconductors are discussed. Near-term applications of liquid-nitrogen depth sensors, current leads, and magnetic bearings are discussed in detail.

Hull, J.R.; Poeppel, R.B.

1992-02-09T23:59:59.000Z

38

Stability and quench protection of high-temperature superconductors  

E-Print Network (OSTI)

In the design and operation of a superconducting magnet, stability and protection are two key issues that determine the magnet's reliability and safe operation. Although the high-temperature superconductor (HTS) is considered ...

Ang, Ing Chea

2006-01-01T23:59:59.000Z

39

High resolution angle-resolved photoemission study of high temperature superconductors: charge-ordering, bilayer splitting and electron-phonon coupling  

E-Print Network (OSTI)

study of high temperature superconductors: charge-ordering,work on high temperature superconductors. These include: (1)interaction in high temperature superconductors. ? 2002

Zhou, Xingjiang; Hussain, Zahid; Shen, Zhi-xun

2003-01-01T23:59:59.000Z

40

A universal high energy anomaly in angle resolved photoemission spectra of high temperature superconductors -- possible evidence of spinon and holon branches  

E-Print Network (OSTI)

spectra of high temperature superconductors possiblefamilies of high temperature superconductors by using angle-families of high temperature superconductors, identi?ed by a

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Phase Transitions in High-Temperature Superconductors  

E-Print Network (OSTI)

superconductors. In particular the vortices play a key role in determining their properties. In this thesis the

Jack Lidmar; Jack Lidmar; Theoretical Physics; Department Ofphysics

1998-01-01T23:59:59.000Z

42

Temperature dependence of vortex charges in high-temperature superconductors  

Science Journals Connector (OSTI)

Using a model Hamiltonian with d-wave superconductivity and competing antiferromagnetic (AF) interactions, the temperature (T) dependence of the vortex charge in high-Tc superconductors is investigated by numerically solving the Bogoliubovde Gennes equations. The strength of the induced AF order inside the vortex core is T dependent. The vortex charge could be negative when the AF order with sufficient strength is present at low temperatures. At higher temperatures, the AF order may be completely suppressed and the vortex charge becomes positive. A first-order-like transition in the T-dependent vortex charge is seen near the critical temperature TAF. For an underdoped sample, the spatial profiles of the induced spin-density wave and the charge-density wave orders could have stripelike structures at TTs. As a result, a vortex charge discontinuity occurs at Ts.

Yan Chen; Z. D. Wang; C. S. Ting

2003-06-03T23:59:59.000Z

43

Local characteristics of heat-radiation superconductor detectors based on high-temperature superconductor films  

Science Journals Connector (OSTI)

Relations are proposed for evaluating the local values of the thermal sensitivity, speed of response, and resolution of a heat radiation detector based on high-temperature superconductor films.

O. S. Esikov; A. I. Krot; I. G. Merinov

1992-06-01T23:59:59.000Z

44

Method of manufacturing a high temperature superconductor with improved transport properties  

SciTech Connect

A method of preparing a high temperature superconductor. A method of preparing a superconductor includes providing a powdered high temperature superconductor and a nanophase paramagnetic material. These components are combined to form a solid compacted mass with the paramagnetic material disposed on the grain boundaries of the polycrystaline high temperature superconductor.

Balachandran, Uthamalingam (Hinsdale, IL); Siegel, Richard W. (Hinsdale, IL); Askew, Thomas R. (Kalamazoo, MI)

2001-01-01T23:59:59.000Z

45

Vortices in high-temperature superconductors  

Science Journals Connector (OSTI)

With the high-temperature superconductors a qualitatively new regime in the phenomenology of type-II superconductivity can be accessed. The key elements governing the statistical mechanics and the dynamics of the vortex system are (dynamic) thermal and quantum fluctuations and (static) quenched disorder. The importance of these three sources of disorder can be quantified by the Ginzburg number Gi=(TcHc2??3)22, the quantum resistance Qu=(e2?)(?n??), and the critical current-density ratio jcjo, with jc and jo denoting the depinning and depairing current densities, respectively (?n is the normal-state resistivity and ?2=mMsuperconductors, leading to interesting effects such as the melting of the vortex lattice, the creation of new vortex-liquid phases, and the appearance of macroscopic quantum phenomena. Introducing quenched disorder into the system turns the Abrikosov lattice into a vortex glass, whereas the vortex liquid remains a liquid. The terms "glass" and "liquid" are defined in a dynamic sense, with a sublinear response ?=?E?j|j?0 characterizing the truly superconducting vortex glass and a finite resistivity ?(j?0)>0 being the signature of the liquid phase. The smallness of jcjo allows one to discuss the influence of quenched disorder in terms of the weak collective pinning theory. Supplementing the traditional theory of weak collective pinning to take into account thermal and quantum fluctuations, as well as the new scaling concepts for elastic media subject to a random potential, this modern version of the weak collective pinning theory consistently accounts for a large number of novel phenomena, such as the broad resistive transition, thermally assisted flux flow, giant and quantum creep, and the glassiness of the solid state. The strong layering of the oxides introduces additional new features into the thermodynamic phase diagram, such as a layer decoupling transition, and modifies the mechanism of pinning and creep in various ways. The presence of strong (correlated) disorder in the form of twin boundaries or columnar defects not only is technologically relevant but also provides the framework for the physical realization of novel thermodynamic phases such as the Bose glass. On a macroscopic scale the vortex system exhibits self-organized criticality, with both the spatial and the temporal scale accessible to experimental investigations.

G. Blatter; M. V. Feigel'man; V. B. Geshkenbein; A. I. Larkin; V. M. Vinokur

1994-10-01T23:59:59.000Z

46

DOE Science Showcase - Understanding High-Temperature Superconductors |  

Office of Scientific and Technical Information (OSTI)

Understanding High-Temperature Superconductors Understanding High-Temperature Superconductors Credit: DOE Scientists have long worked to understand one of the great mysteries of modern physics - the origin and behavior of high-temperature superconductors (HTS) that are uniquely capable of transmitting electricity with zero loss when chilled to subzero temperatures. For decades there have been competing theories and misunderstandings of how HTS materials actually work and they have remained fundamentally puzzling to physicists. Solving this mystery has the potential to revolutionize the planet's energy infrastructure from generation to transmission and grid-scale storage. Recent technical breakthroughs in this quest are being discovered by DOE scientists and their collaborators. Read about HTS technology, basic

47

Reciprocity theorem in high-temperature superconductors  

E-Print Network (OSTI)

This article is devoted to the problem of the validity of the reciprocity theorem in high-temperature

Ivan Jane?ek

2002-01-01T23:59:59.000Z

48

Scaling in high-temperature superconductors by  

E-Print Network (OSTI)

A Hartree approximation is used to study the interplay of two kinds of scaling which arise in high-temperature

Ian D Lawrie

1994-01-01T23:59:59.000Z

49

Two Phase Transitions Make a High-Temperature Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

Two Phase Transitions Make a High-Temperature Superconductor Print Two Phase Transitions Make a High-Temperature Superconductor Print Superconductivity-conceptually remarkable and practically revolutionary-is a quantum phenomenon in which bound electron pairs flow through a material in perfect synchrony, without friction. Conventional superconducting materials reach this state via a single thermal phase transition at a critical temperature (Tc). It was generally believed that such a picture also applied to the copper oxide (cuprate) superconductors-first discovered 25 years ago and the current record holders for highest Tc. However, three groups of researchers who performed measurements on the same cuprate material recently joined forces to prove that this view is inaccurate. Their work showed that another phase transition actually exists at a higher temperature in the cuprate phase diagram, below which electrons, instead of pairing up, organize themselves in a drastically different way.

50

Two Phase Transitions Make a High-Temperature Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

Two Phase Transitions Make a High-Temperature Superconductor Print Two Phase Transitions Make a High-Temperature Superconductor Print Superconductivity-conceptually remarkable and practically revolutionary-is a quantum phenomenon in which bound electron pairs flow through a material in perfect synchrony, without friction. Conventional superconducting materials reach this state via a single thermal phase transition at a critical temperature (Tc). It was generally believed that such a picture also applied to the copper oxide (cuprate) superconductors-first discovered 25 years ago and the current record holders for highest Tc. However, three groups of researchers who performed measurements on the same cuprate material recently joined forces to prove that this view is inaccurate. Their work showed that another phase transition actually exists at a higher temperature in the cuprate phase diagram, below which electrons, instead of pairing up, organize themselves in a drastically different way.

51

Two Phase Transitions Make a High-Temperature Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

Two Phase Transitions Make a High-Temperature Superconductor Print Two Phase Transitions Make a High-Temperature Superconductor Print Superconductivity-conceptually remarkable and practically revolutionary-is a quantum phenomenon in which bound electron pairs flow through a material in perfect synchrony, without friction. Conventional superconducting materials reach this state via a single thermal phase transition at a critical temperature (Tc). It was generally believed that such a picture also applied to the copper oxide (cuprate) superconductors-first discovered 25 years ago and the current record holders for highest Tc. However, three groups of researchers who performed measurements on the same cuprate material recently joined forces to prove that this view is inaccurate. Their work showed that another phase transition actually exists at a higher temperature in the cuprate phase diagram, below which electrons, instead of pairing up, organize themselves in a drastically different way.

52

Two Phase Transitions Make a High-Temperature Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

Two Phase Transitions Make a High-Temperature Superconductor Print Two Phase Transitions Make a High-Temperature Superconductor Print Superconductivity-conceptually remarkable and practically revolutionary-is a quantum phenomenon in which bound electron pairs flow through a material in perfect synchrony, without friction. Conventional superconducting materials reach this state via a single thermal phase transition at a critical temperature (Tc). It was generally believed that such a picture also applied to the copper oxide (cuprate) superconductors-first discovered 25 years ago and the current record holders for highest Tc. However, three groups of researchers who performed measurements on the same cuprate material recently joined forces to prove that this view is inaccurate. Their work showed that another phase transition actually exists at a higher temperature in the cuprate phase diagram, below which electrons, instead of pairing up, organize themselves in a drastically different way.

53

Factors affecting characterization of bulk high-temperature superconductors  

SciTech Connect

Three major factors affect the characterization of bulk high-temperature superconductors in terms of their levitation properties during interaction with permanent magnets. First, the appropriate parameter for the permanent magnet is internal magnetization, not the value of the magnetic field measured at the magnet`s surface. Second, although levitation force grows with superconductor thickness and surface area, for a given permanent magnet size, comparison of levitation force between samples is meaningful when minimum values are assigned to the superconductor size parameters. Finally, the effect of force creep must be considered when time-averaging the force measurements. In addition to levitational force, the coefficient of friction of a levitated rotating permanent magnet may be used to characterize the superconductor.

Hull, J.R. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-11-01T23:59:59.000Z

54

Electronic-Structure of High-Temperature Superconductors  

E-Print Network (OSTI)

, and for the corresponding metal atoms in related high-temperature superconductors. These peaks should be observable in electron energy-loss spectroscopy's and 6nal-state photoemission spectrosco- py 20 The calculated valences d,n are again given in Table II. Notice... again neatly cancel in YBa2Cu307. In summary, we have calculated the electronic struc- tures of the most typical members of the two known classes of high-temperature superconductors. The present results, obtained with a simple tight-binding model...

RICHERT, BA; Allen, Roland E.

1988-01-01T23:59:59.000Z

55

Pseudogap and Superconducting Gap in High-Temperature Superconductors  

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Pseudogap and Superconducting Gap in Pseudogap and Superconducting Gap in High-Temperature Superconductors Two decades after the discovery of first high temperature superconductors, the microscopic mechanism of high-Tc superconductivity remains elusive. In conventional superconductors, it has been well established that electrons form so-called "Cooper pairs" to give rise to superconductivity. The pair binding manifests itself as an energy gap in many spectroscopic measurements. This energy gap, known as superconducting gap, appears at the superconducting transition temperature Tc where the resistance also vanishes. For high temperature superconductors, the story is more complicated. Over a wide region of compositions and temperatures, there exists an energy gap well above Tc. This energy gap is called pseudogap [1], because there is no direct correlation to the superconducting transition. The origin of this pseudogap and its relation to the superconducting gap are believed to hold the key for understanding the mechanism of high-Tc superconductivity - one of the outstanding problems in condensed matter physics. In this regard, researchers Kiyohisa Tanaka and Wei-Sheng Lee, along with their co-workers in Prof. Zhi-Xun Shen's group at Stanford University, have recently made an important discovery about the coexistence of two distinct energy gaps that have opposite doping dependence. Their observation not only provides a natural explanation for the contradictory results about the superconducting gap deduced from different experimental techniques, but also has profound implications on the mechanism of high-Tc superconductivity.

56

Particle-hole symmetry broken pseudogap in high temperature superconductors  

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Particle-hole symmetry broken pseudogap in Particle-hole symmetry broken pseudogap in high temperature superconductors High-temperature (Tc) superconductivity is one of the most important topics in condensed matter physics. Despite extensive studies over more than two decades, the microscopic mechanism of high temperature superconductivity still remains elusive due to many unconventional properties that are not well understood. Among them, the most mysterious behavior of high-Tc superconductor is the nature of so called "pseudogap", which has been a focus of the field for many years. In conventional superconductors, a gap exists in the energy absorption spectrum only below Tc, corresponding to the energy price to pay for breaking a Cooper pair of electrons. In high-Tc cuprate superconductors, an energy gap called the pseudogap exists above Tc but below T*, and is controversially attributed either to pre-formed superconducting pairs or to competing phases. Recently, by carefully studying the "symmetry" of the gap, researchers Makoto Hashimoto and Rui-Hua He, along with their co-workers in Prof. Zhi-Xun Shen's group at Stanford University, have found crucial evidence suggesting that the particle-hole symmetry required by superconductivity is broken in the pseudogap state.

57

Effect of a constant magnetic field on echo signals in high-temperature superconductor powders  

Science Journals Connector (OSTI)

The generation of acoustic and vortex oscillations in high-temperature superconductor (HTSC) powders excited by radiofrequency (rf...

E. G. Apushkinskii; M. S. Astrov

2013-03-01T23:59:59.000Z

58

Confinement of Spin and Charge in High-Temperature Superconductors  

E-Print Network (OSTI)

By exploiting the internal gauge-invariance intrinsic to a spin-charge separated electron, we show that such degrees of freedom must be confined in two-dimensional superconductors experiencing strong inter-electron repulsion. We also demonstrate that incipient confinement in the normal state can prevent chiral spin-fluctuations from destroying the cross-over between strange and psuedo-gap regimes in under-doped high-temperature superconductors. Last, we suggest that the negative Hall anomaly observed in these materials is connected with this confinement effect.

J. P. Rodriguez; Pascal Lederer

1996-04-17T23:59:59.000Z

59

In situ doping control of the surface of high-temperature superconductors  

E-Print Network (OSTI)

LETTERS In situ doping control of the surface of high-temperature superconductors M. A. HOSSAIN1 to systematic studies of high- temperature superconductors, such as creating new electron- doped superconductors.1038/nphys998 Central to the understanding of high-temperature superconductivity is the evolution

Michelson, David G.

60

Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors  

E-Print Network (OSTI)

and ferrochalcogenides are three classes of unconventional high- temperature superconductors, who share similar phase interactions. Our result offers a principle guide to search for new high temperature superconductors. 1 ar temperature superconductors Jiangping Hu1, 2, and Hong Ding1, 1 Beijing National Laboratory for Condensed

Hu, Jiangping

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Competing order and the asymmetric tunneling spectrum in high temperature cuprate superconductors  

E-Print Network (OSTI)

Competing order and the asymmetric tunneling spectrum in high temperature cuprate superconductors- terplay between them are two major tasks in this field. In high temperature cuprate superconductors temperature superconductors remains a challenging puzzle to be solved. A comprehensive theory to understand

Hu, Jiangping

62

5 - High temperature superconductor (HTS) magnets  

Science Journals Connector (OSTI)

Abstract: At the time of writing, high temperature superconducting magnets have not fulfilled their early promise, mainly because of the difficulties in getting these reactive and brittle ceramics into wire form and, consequently, their expense. However, for some niche applications, HTS magnets have been developed. In this chapter, the author outlines his experience of building four such systems after introductory discussions about superconducting magnets in general and design considerations. The recent commercial availability of so-called second-generation (2G) coated conductors opens up a more promising scenario, provided the cost can come down. This scenario is discussed and some conclusions are drawn.

H. Jones

2012-01-01T23:59:59.000Z

63

"Phun" with Photoelectrons What Sets the Tc in Cuprate High-Temperature Superconductors?  

E-Print Network (OSTI)

"Phun" with Photoelectrons or What Sets the Tc in Cuprate High-Temperature Superconductors? Dan famous and exotic of correlated electron materials are high-temperature cuprate superconductors, which the pair-breaking energy scale . In contrast to conventional superconductors in which the superconducting

Glashausser, Charles

64

Nearly Perfect Fluidity in a High Temperature Superconductor  

E-Print Network (OSTI)

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, {\\eta}/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the Quark-Gluon Plasma (QGP) and in unitary atomic Fermi gases (UFG), exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use Angle Resolve Photoemission Spectroscopy (ARPES) to measure the temperature dependence of an electronic analogue of {\\eta}/s in an optimally doped cuprate high temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

J. D. Rameau; T. J. Reber; H. -B. Yang; S. Akhanjee; G. D. Gu; S. Campbell; P. D. Johnson

2014-09-19T23:59:59.000Z

65

Nearly Perfect Fluidity in a High Temperature Superconductor  

E-Print Network (OSTI)

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, {\\eta}/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the Quark-Gluon Plasma (QGP) and in unitary atomic Fermi gases (UFG), exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use Angle Resolve Photoemission Spectroscopy (ARPES) to measure the temperature dependence of an electronic analogue of {\\eta}/s in an optimally doped cuprate high temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

Rameau, J D; Yang, H -B; Akhanjee, S; Gu, G D; Campbell, S; Johnson, P D

2014-01-01T23:59:59.000Z

66

Nearly perfect fluidity in a high-temperature superconductor  

Science Journals Connector (OSTI)

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, ?/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of ?/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

J. D. Rameau; T. J. Reber; H.-B. Yang; S. Akhanjee; G. D. Gu; P. D. Johnson; S. Campbell

2014-10-13T23:59:59.000Z

67

Calculating levitation forces in the magnet-high-temperature superconductor systems  

Science Journals Connector (OSTI)

A new method of calculation of the magnetic levitation force in the permanent magnet-high-temperature superconductor systems is proposed based on the Maxwell ... the gap width calculated for various regimes of superconductor

Yu. S. Ermolaev; I. A. Rudnev

2005-12-01T23:59:59.000Z

68

Temperature dependence of the superheating field for superconductors in the high-London limit  

E-Print Network (OSTI)

Temperature dependence of the superheating field for superconductors in the high- London limit G is a characteristic property of both types I and II superconductors. In this paper we consider the temperature of the superheated Meissner state in type II superconductors with 1 beyond Ginzburg-Landau theory, which

Sethna, James P.

69

High-Temperature Superconductor Coil System for a Particle Detector Analyzing Magnet  

Science Journals Connector (OSTI)

The high energy physics experiment known as the Main ... . We have evaluated the feasibility of a high-temperature superconductor coil system that provides a 25,000...

R. C. Niemann; L. R. Turner; M. W. Morgan; P. Haldar

1998-01-01T23:59:59.000Z

70

Microwave characterization of high-temperature superconductors  

SciTech Connect

Thick (10-15 {mu}m) Tl-Ba-Ca-Cu-O films have been deposited onto yttria-stabilized zirconia and Ag substrates by d.c. magnetron sputtering techniques. Direct deposition onto 1'' diameter yttria-stabilized zirconia yields films with typical 22 GHz surface resistance (R{sub s}) values of 5.2 {plus minus} 2 m{Omega} and 52 {plus minus} 2 m{Omega} at 10 K and 77 K, respectively. For comparison, R{sub s} of Cu at this same frequency is 10 m{Omega} at 4 K and 22 m{Omega} at 77 K. Tl-Ba-Ca-Cu-O films have also been deposited onto 1'' diameter Ag substrates using Au/Cu, Cu, and BaF{sub 2} buffer layers. The lowest R{sub s} values were obtained on films with a BaF{sub 2} buffer layer, typical values being 7.8 {plus minus} 2 m{Omega} and 30.6 {plus minus} 2 m{Omega} (measured at 22 GHz) at 10 K and 77 K, respectively. Larger films (1.5'' diameter) with similar R{sub s} values were prepared using this same technique, demonstrating that the fabrication process can be scaled to larger surface areas. These films are promising for radiofrequency cavity applications because they are thick (50-75 times the London penetration depth), have relatively large surface areas, are fabricated on metallic substrates, and have R{sub s} values that are competitive with Cu at 77 K and are lower than Cu at 4 K. Because they are polycrystalline and unoriented, it is anticipated that their R{sub s} values can be lowered by improving the processing technique. High-quality films of YBa{sub 2}Cu{sub 3}O{sub 7} have been electron-beam deposited onto 1'' LaGaO{sub 3} and 1.5'' LaAlO{sub 3} substrates. The 1'' sample is characterized by R{sub s} values of 0.2 {plus minus} 0.1 m{Omega} at 4 K and 18.6 {plus minus} 2 m{Omega} at 77 K. The 4-K value is only 2-4 times higher than Nb. The 1.5'' sample has R{sub s} values (measured at 18 GHz) of 0.93 {plus minus} 2 m{Omega} and 71 {plus minus} 3 m{Omega} at 10 K and 77 K, respectively. 18 refs., 8 figs.

Cooke, D.W.; Gray, E.R.; Arendt, P.N.; Beery, J.G.; Bennett, B.L.; Brown, D.R.; Houlton, R.J.; Jahan, M.S.; Klapetzky, A.J.; Maez, M.A.; Raistrick, I.D.; Reeves, G.A.; Rusnak, B.

1989-01-01T23:59:59.000Z

71

Acoustic studies of single?crystal high?temperature superconductors  

Science Journals Connector (OSTI)

The acoustic properties of single crystals of the high?temperature superconductor YBa 2 Cu 3 O 7 have been measured at temperatures between 0.1 and 300 K for frequencies near 103 and 109 Hz. In the GHz regime longitudinal modes have been studied for propagation directions parallel and perpendicular to the c axis. At Tc there is a discontinuity in the soundvelocities and their temperature derivatives from which the anisotropic strain dependences of Tc are obtained. In the kHz regime resonant excitation of flexural modes in thin reeds of YBa 2 Cu 3 O 7 crystals has permitted precise measurement of acoustic damping and dispersion. The temperature?dependent damping is characterized by at least five features associated with the relaxation of defects. At temperatures below 1 K the velocity of sound is consistent with the presence of a broad glasslike distribution of tunneling modes.

Brage Golding; W. H. Haemmerle; L. F. Schneemeyer

1988-01-01T23:59:59.000Z

72

Resonant Spin Excitation in an Overdoped High Temperature Superconductor  

Science Journals Connector (OSTI)

An inelastic neutron scattering study of overdoped Bi2Sr2CaCu2O8+? ( Tc=83K) has revealed a resonant spin excitation in the superconducting state. The mode energy is Eres=38.0meV, significantly lower than in optimally doped Bi2Sr2CaCu2O8+? ( Tc=91K, Eres=42.4meV). This observation, which indicates a constant ratio Eres/kBTc?5.4, helps resolve a long-standing controversy about the origin of the resonant spin excitation in high temperature superconductors.

H. He; Y. Sidis; P. Bourges; G. D. Gu; A. Ivanov; N. Koshizuka; B. Liang; C. T. Lin; L. P. Regnault; E. Schoenherr; B. Keimer

2001-02-19T23:59:59.000Z

73

Pinning in a porous high-temperature superconductor Bi2223  

Science Journals Connector (OSTI)

The current-voltage characteristics of a porous superconductor Bi2Sr2Ca2Cu3O x (Bi2223) have been measured at temperatures in the range from 10 to 90 ... been found that the ele...

K. Yu. Terentev; D. M. Gokhfeld; S. I. Popkov

2011-12-01T23:59:59.000Z

74

Nanostructured high-temperature superconductors: Creation of strong-pinning columnar defects in  

E-Print Network (OSTI)

Nanostructured high-temperature superconductors: Creation of strong-pinning columnar defects the growth and incorporation of MgO nanorods into high temperature superconductors (HTS's) has been developed a limitation to the performance of HTS materials at high temperatures and magnetic fields.11­13 The traditional

Yang, Peidong

75

Penetration of ac magnetic field into bulk high-temperature superconductors: Experiment and simulation  

E-Print Network (OSTI)

Penetration of ac magnetic field into bulk high-temperature superconductors: Experiment from these models for high-temperature superconductors are observed at the op- eration in ac fields condi- tions is very important for correct modeling magnetic prop- erties of high-temperature

Paperno, Eugene

76

Modeling and experimental investigation of microstrip resonators and filters based on High-Temperature Superconductor films  

Science Journals Connector (OSTI)

Complex approach to the investigation of microstrip resonators and filters based on High-Temperature Superconductor (HTS) films is described, which includes...

M. F. Sitnikova; I. B. Vendik; O. G. Vendik; D. V. Kholodnyak

2010-09-01T23:59:59.000Z

77

Electrodynamics of high-temperature superconductors investigated with coherent terahertz pulse spectroscopy  

Science Journals Connector (OSTI)

Recent experimental investigations of the electrodynamic properties of high-temperature superconductors in the terahertz regime are reviewed. Transmission measurements were performed...

Brorson, S D; Buhleier, R; Trofimov, I E; White, J O; Ludwig, Ch; Balakirev, F F; Habermeier, H -U; Kuhl, Juergen

1996-01-01T23:59:59.000Z

78

A simple, inexpensive device for measuring the critical temperature of a high-temperature superconductor  

Science Journals Connector (OSTI)

A simple, inexpensive device for measuring the critical temperature of a high-temperature superconductor ... This note describes a simple, inexpensive method of measuring the temperature at which the Meissner effect exists in a disk of YBa2Cu3O7-x. ...

David B. Green; Dijon Douphner; Bennett Hutchinson

1992-01-01T23:59:59.000Z

79

An equation of state of high-temperature superconductor  

Science Journals Connector (OSTI)

In the present paper the expression of cohesive energy and the bulk modulus as a function of volume are formulated for high-T c copper oxide superconductors. Th...

Rajiv Kumar Pandey; B. R. K. Gupta

1997-12-01T23:59:59.000Z

80

A. Bianconi (ed.) Symmetry and Heterogeneity in High Temperature Superconductors, 21-53  

E-Print Network (OSTI)

A. Bianconi (ed.) Symmetry and Heterogeneity in High Temperature Superconductors, 21-53 NATO I.2 FESHBACH SHAPE RESONANCES IN MULTIBAND HIGH TC SUPERCONDUCTORS Antonio Bianconi, Matteo Filippi trick that bestows to the system the property to resist to the decoherence attacks of high temperature

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Potential impact of high temperature superconductors on maglev transportation  

SciTech Connect

This report describes the potential impact that high-temperature superconductors (HTSs) may have on transportation by magnetically levitated vehicles. It is not intended as a planning document, but rather as an overview of potential HTS applications to magnetic-levitation (maglev) transportation. The present maglev program in the United States is summarized, and the present status of development of HTSs is described. Areas identified for possible impact on maglev technology are (1) liquid-nitrogen-cooled levitation magnets, (2) magnetic-field shielding of the passenger compartment, (3) superconducting magnetic energy storage for wayside power, (4) superconducting bearings for flywheel energy storage for wayside power, (5) downleads to continuously powered liquid-helium-cooled levitation magnets, and (6) liquid-hydrogen-cooled levitation magnets and linear motor propulsion windings. Major technical issues that remain to be resolved for the use of HTSs in maglev applications include thermal magnetic stability, mechanical properties, and critical current density at liquid-nitrogen temperatures.

Hull, J.R.

1992-02-01T23:59:59.000Z

82

Applications of high-temperature superconductors in power technology  

Science Journals Connector (OSTI)

Since the discovery of the first high-temperature superconductors (HTSs) in the late 1980s, many materials and families of materials have been discovered that exhibit superconductivity at temperatures well above 20?K. Of these, several families of HTSs have been developed for use in electrical power applications. Demonstration of devices such as motors, generators, transmission lines, transformers, fault-current limiters, and flywheels in which HTSs and bulk HTSs have been used has proceeded to ever larger scales. First-generation wire, made from bismuth-based copper oxides, was used in many demonstrations. The rapid development of second-generation wire, made by depositing thin films of yttrium-based copper oxide on metallic substrates, is expected to further accelerate commercial applications. Bulk HTSs, in which large single-grain crystals are used as basic magnetic components, have also been developed and have potential for electrical power applications.

John R Hull

2003-01-01T23:59:59.000Z

83

High-Tc Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94305 High-temperature superconductors (HTSC's), following their remarkable discovery in 1986,...

84

Anisotropic high temperature superconductors as variable resistors and switches  

SciTech Connect

Several anisotropic high temperature superconductors show critical current densities which are strongly dependent on the direction of an applied external magnetic field. The resistance of a sample can change by several orders of magnitude by applying a magnetic field. The potential for using the field dependent variable resistor or switch for applications in power systems is evaluated. Test results with small samples are presented. The requirements for large scale applications are outlined. The magnetic field triggering requirement, the frequency response of the device, use in 60 Hz ac circuits and heat transfer consideration are investigated. Several application examples are discussed. Use of variable resistor as a fault current limiter, as a switching element in rectifier circuitry and as an improved dump resistor for a superconducting magnet is presented.

Boenig, H.J.; Daugherty, M.A.; Fleshler, S.; Maley, M.P.; Mueller, F.M.; Prenger, F.C.; Coulter, J.Y.

1994-12-01T23:59:59.000Z

85

Temperature dependence of the gaps of high-temperature superconductors in the Fermi-arc region  

Science Journals Connector (OSTI)

It is shown how in a high-temperature superconductor, the length of the Fermi arc can be obtained from the doping dependence of the pseudogap and the superconducting gap. In the momentum region spanned by the Fermi arc, the pseudogap temperature dependence follows that of the superconducting gap. The close interconnection of the two gaps suggests that they are both an essential part of the high-temperature superconductivity.

S. Hfner and F. Mller

2008-07-23T23:59:59.000Z

86

Superconductor-insulator transition induced by electrostatic charging in high temperature superconductors.  

E-Print Network (OSTI)

??Ultrathin YBa2Cu3O7?x films were grown on SrTiO3 substrates in a high pressure oxygen sputtering system to study the superconductor-insulator transition by electrostatic charging. While backside (more)

Leng, Xiang

2011-01-01T23:59:59.000Z

87

Peculiarities of the current-voltage characteristics of a Josephson medium in a YBCO high-temperature superconductor  

Science Journals Connector (OSTI)

The influence of a weak magnetic field (H high-temperature superconductor (HTSC) near the superconducting transitio...

M. A. Vasyutin

2013-12-01T23:59:59.000Z

88

Current transport along the [001] axis of YBCO in low-temperature superconductor-normal metal-high-temperature superconductor heterostructures  

Science Journals Connector (OSTI)

The electrophysical properties of heterojunctions several microns in size, obtained by successive deposition of the metal-oxide high-temperature superconductor YBa2Cu3Ox..., a normal metal Au, and the low-temperature

F. V. Komissinskii; G. A. Ovsyannikov

1999-12-01T23:59:59.000Z

89

Imaging the two gaps of the high temperature superconductor Pb-Bi?Sr?CuO??x  

E-Print Network (OSTI)

The nature and behavior of electronic states in high temperature superconductors are the center of much debate. The pseudogap state, observed above the superconducting transition temperature Tc, is seen by some as a precursor ...

Yi, Ming, S.M. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

90

Hybrid High-Temperature-SuperconductorSemiconductor Tunnel Diode  

Science Journals Connector (OSTI)

We report the demonstration of hybrid high-Tc-superconductorsemiconductor tunnel junctions, enabling new interdisciplinary directions in condensed matter research. The devices are fabricated by our newly developed mechanical-bonding technique, resulting in high-Tc-superconductorsemiconductor tunnel diodes. Tunneling-spectra characterization of the hybrid junctions of Bi2Sr2CaCu2O8+? combined with bulk GaAs, or a GaAs/AlGaAs quantum well, exhibits excess voltage and nonlinearity, similarly to spectra obtained in scanning-tunneling microscopy, and is in good agreement with theoretical predictions for a d-wave-superconductornormal-material junction. Additional junctions are demonstrated using Bi2Sr2CaCu2O8+? combined with graphite or Bi2Te3. Our results pave the way for new methods in unconventional superconductivity studies, novel materials, and quantum technology applications.

Alex Hayat; Parisa Zareapour; Shu Yang F. Zhao; Achint Jain; Igor G. Savelyev; Marina Blumin; Zhijun Xu; Alina Yang; G. D. Gu; Harry E. Ruda; Shuang Jia; R. J. Cava; Aephraim M. Steinberg; Kenneth S. Burch

2012-12-27T23:59:59.000Z

91

Temperature evolution of the spectral peak in high-temperature superconductors  

Science Journals Connector (OSTI)

Recent photoemission data in the high-temperature cuprate superconductor Bi2212 have been interpreted in terms of a sharp spectral peak with a temperature-independent lifetime, whose weight strongly decreases upon heating. By a detailed analysis of the data, we are able to extract the temperature dependence of the electron self-energy, and demonstrate that this interpretation is misleading. Rather, the spectral peak loses its integrity above Tc due to a large reduction in the electron lifetime.

M. R. Norman; A. Kaminski; J. Mesot; J. C. Campuzano

2001-03-22T23:59:59.000Z

92

Applied High-Temperature Superconductor Bulks and Wires to Rotating Machines for Marine Propulsion  

Science Journals Connector (OSTI)

High-temperature superconductors (HTS) allow providing to high-torque density rotating machines a compact, efficient, and excellent operation. Field poles that act as magnets, providing a magnetic field of more t...

Brice Felder; Motohiro Miki; Yosuke Kimura

2011-01-01T23:59:59.000Z

93

Receiver protecting device based on microstrip structure with high-temperature superconductor film  

Science Journals Connector (OSTI)

New design of an effective device for protection against high-power electromagnetic pulses has been created based ... third resonator based on a thin film of high-temperature superconductor (HTSC) occurring in th...

B. A. Belyaev; I. V. Govorun; A. A. Leksikov; A. M. Serzhantov

2012-03-01T23:59:59.000Z

94

Development and Investigation of a Dipole Magnet with a High-Temperature Superconductor Winding  

Science Journals Connector (OSTI)

The structure of a dipole magnet with an iron yoke, where the winding is made of a Bi-2223 high-temperature superconductor, has been developed and the magnet has been built at the Institute of High-Energy Physics...

A. I. Ageev; I. V. Bogdanov; V. V. Zubko; S. S. Kozub; K. P. Myznikov

2002-12-01T23:59:59.000Z

95

Temperature dependence of the lower critical field and strong pinning in high-temperature superconductors  

Science Journals Connector (OSTI)

We show, within the framework of the Ginzburg-Landau theory, that both the conventional and the anomalous temperature dependence of the lower critical field observed in high-temperature superconductors may result from the flux penetration through a set of separated microdefects. Microdefects modeled by normal layers with proximity-induced superconductivity can produce drastic enhancement of the lower critical field at low temperatures and can provide strong-pinning centers. The pinning interaction between an isolated vortex and the normal layer is primarily magnetic at high temperatures. At low temperatures, magnetic interaction is reduced, due to the increase of the normal-layer coherence length.

Dragomir Davidovi? and Ljiljana Dobrosavljevi?-Gruji?

1991-02-01T23:59:59.000Z

96

Development of high temperature superconductors for magnetic field applications  

SciTech Connect

The key requirement for magnetic field applications of high temperature superconductor (HTS) materials is to have conductors with high transport critical current density available for magnet builders. After 3 or 4 years of being without any such object, conductor makers have had recent success in producing simple conductor prototypes. These have permitted the construction of simple HTS magnets having self fields exceeding 1 tesla at 4K. Thus the scientific feasibility of making powerful HTS magnets has been demonstrated. Attention to the technological aspects of making HTS conductors for magnets with strong flux pinning and reduced superconducting granularity is now sensible and attractive. However, extrinsic defects such as filament sausaging, cracking, misaligned grains and other perturbation to long range current flow must be controlled at a low level if the benefit of intrinsic improvements to the critical current density is to be maintained in the conductor form. Due to the great complexity of the HTS materials, there is sometimes confusion as to whether a given sample has an intrinsically or extrinsically limited critical current density. Systematic microstructure variation experiments and resistive transition analysis are shown to be particularly helpful in this phase of conductor development.

Larbalestier, D.C.

1991-01-01T23:59:59.000Z

97

Development of high temperature superconductors for magnetic field applications  

SciTech Connect

The key requirement for magnetic field applications of high temperature superconductor (HTS) materials is to have conductors with high transport critical current density available for magnet builders. After 3 or 4 years of being without any such object, conductor makers have had recent success in producing simple conductor prototypes. These have permitted the construction of simple HTS magnets having self fields exceeding 1 tesla at 4K. Thus the scientific feasibility of making powerful HTS magnets has been demonstrated. Attention to the technological aspects of making HTS conductors for magnets with strong flux pinning and reduced superconducting granularity is now sensible and attractive. However, extrinsic defects such as filament sausaging, cracking, misaligned grains and other perturbation to long range current flow must be controlled at a low level if the benefit of intrinsic improvements to the critical current density is to be maintained in the conductor form. Due to the great complexity of the HTS materials, there is sometimes confusion as to whether a given sample has an intrinsically or extrinsically limited critical current density. Systematic microstructure variation experiments and resistive transition analysis are shown to be particularly helpful in this phase of conductor development.

Larbalestier, D.C.

1991-12-31T23:59:59.000Z

98

The Astro-H high temperature superconductor lead assemblies  

Science Journals Connector (OSTI)

Abstract The Soft X-ray Spectrometer (SXS) instrument, one of several instruments on JAXAs Astro-H mission, will observe diffuse X-ray sources with unparalleled spectral resolution using a microcalorimeter array operating at 50mK. The array is cooled with a multi-stage Adiabatic Demagnetization Refrigerator mounted on a 40l helium tank. The tank is at the center of a typical shell in shell cryostat, with the innermost shield cooled by a JT cryocooler, and successive outer shields cooled by stirling-cycle cryocoolers. To achieve a multi-year liquid helium lifetime and to avoid exceeding the limited capacity of the JT cooler, very strict requirements are placed on every source of heat leak into these surfaces from the higher temperature shields. However, each ADR stage draws a maximum of 2A, and the WiedemannFranz Law precludes even an optimized set of normal-metal leads capable of such high current from achieving the required low thermal conductance. Instead, a set of lead assemblies have been developed based on narrow high temperature superconductor (HTS) tapes derived from commercially available coated conductors. Although the HTS tapes are flexible and have high tensile strength, they are extremely sensitive to damage through a number of mechanisms. A robust set of assemblies have been developed that provide mechanical support to the tapes, provide appropriate interfaces at either end, and yet still meet the challenging thermal requirements. An Engineering Model (EM) set of HTS lead assemblies have survived environmental testing, both as individual units and as part of the EM cryostat, and have performed without problem in recent operation of the EM instrument. The Flight Model (FM) HTS lead assemblies are currently nearing completion.

E.R. Canavan; B.L. James; T.P. Hait; A. Oliver; D.F. Sullivan

2014-01-01T23:59:59.000Z

99

Gorkov equations for a pseudogapped high-temperature superconductor  

Science Journals Connector (OSTI)

A phenomenological theory of superconductivity based on the two-body Cooperon propagator is presented. This theory takes the form of a modified Gorkov equation for the Greens function and allows one to model the effect of local superconducting correlations and long-range phase fluctuations on the spectral properties of high-temperature superconductors, both above and below Tc. A model is proposed for the Cooperon propagator, which provides a simple physical picture of the pseudogap phenomenon, as well as insights into the doping dependence of the spectral properties. Numerical calculations of the density of states and spectral functions based on this model are also presented, and compared with the experimental tunneling (STM) and photoemission (ARPES) data. It is found, in particular, that the sharpness of the peaks in the density of states is related to the strength and the range of the superconducting correlations and that the apparent pseudogap in STM and ARPES can be different, although the underlying model is the same.

B. Giovannini and C. Berthod

2001-03-21T23:59:59.000Z

100

Hybrid high-temperature superconductor-semiconductor tunnel diode  

E-Print Network (OSTI)

We report the demonstration of hybrid high-Tc-superconductor-semiconductor tunnel junctions, enabling new interdisciplinary directions in condensed matter research. The devices were fabricated by our newly-developed mechanical bonding technique, resulting in high-Tc-semiconductor planar junctions acting as superconducting tunnel diodes. Tunneling-spectra characterization of the hybrid junctions of Bi2Sr2CaCu2O8+{\\delta} combined with bulk GaAs, or a GaAs/AlGaAs quantum well, exhibits excess voltage and nonlinearity - in good agreement with theoretical predictions for a d-wave superconductor-normal material junction, and similar to spectra obtained in scanning tunneling microscopy. Additional junctions are demonstrated using Bi2Sr2CaCu2O8+{\\delta} combined with graphite or Bi2Te3. Our results pave the way for new methods in unconventional superconductivity studies, novel materials and quantum technology applications.

Alex Hayat; Parisa Zareapour; Shu Yang F. Zhao; Achint Jain; Igor G. Savelyev; Marina Blumin; Zhijun Xu; Alina Yang; G. D. Gu; Harry E. Ruda; Shuang Jia; R. J. Cava; Aephraim M. Steinberg; Kenneth S. Burch

2013-01-09T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Measurement of the vortex depinning force in a high temperature superconductor  

E-Print Network (OSTI)

Introduction: Superconductivity is one of those subjects in physics that is as captivating theoretically as it is experimentally interesting. The dual driving force of commercial demand for high-temperature superconductors ...

Whitehead, Andrew Patrick

2005-01-01T23:59:59.000Z

102

Femtosecond Study of Photodoping Phenomena in a Parent Compound of a High-Temperature Superconductor  

Science Journals Connector (OSTI)

We present the first spectrally-resolved study of the femtosecond dynamics in La2CuO4, the undoped parent-compound of the high-temperature superconductor. The...

Beyer, Markus; Kim, Kyungwan; Kabanov, Viktor; Schfer, Hanjo; Logvenov, Gennady; Bozovic, Ivan; Demsar, Jure

103

Studies of heterogeneity properties of selected high-temperature superconductor surfaces  

Science Journals Connector (OSTI)

Nitrogen adsorption measured at 77 K was used to characterize the surface heterogeneity of high-temperature superconductor surfaces. Properties relating to adsorption and porosity ... microscopy (AFM) for a serie...

P. Staszczuk; D. Sternik; G. W. Ch?dzy?ski

2006-09-01T23:59:59.000Z

104

Features of technology of high-temperature superconductor films for microwave filters  

Science Journals Connector (OSTI)

The characteristics of fourth-order bandpass microwave filters based on high-temperature super-conductor (HTS) films have been numerically simulated and experimentally measured for the devices based on YBCO fi...

I. B. Vendik; O. G. Vendik; K. N. Zemlyakov; I. V. Kolmakova

2011-05-01T23:59:59.000Z

105

High-frequency vortex dynamics and dissipation of high-temperature superconductors  

Science Journals Connector (OSTI)

The high-frequency vortex dynamics of high-temperature superconductors near the flux-line depinning threshold is investigated based on a thermally activated flux-flow (TAFF) model. Dissipation due to vortex motion driven by a microwave electromagnetic field is studied as a function of the frequency, temperature, dc magnetic field, and microwave power. The generalized TAFF model is also compared to the conventional flux-creep theory and is found qualitatively consistent.

N.-C. Yeh

1991-01-01T23:59:59.000Z

106

Studies of High Temperature Nova Science Publishers, Inc. Superconductors All Rights of reproduction in any form reserved  

E-Print Network (OSTI)

Studies of High Temperature © Nova Science Publishers, Inc. Superconductors All Rights). Like high-Tc materials, -(BEDT-TTF)2X superconductors are characterized by a layered structure of reproduction in any form reserved Volume 37 ISBN 1-56072-789-6 MAGNETIZATION OF ORGANIC SUPERCONDUCTORS

Paris-Sud 11, Université de

107

Probing the Gauge Structure of high-temperature superconductors  

E-Print Network (OSTI)

We suggest that a spin-charge separating ansatz, leading to non-Abelian $SU(2) \\otimes U_S(1)$ gauge symmetries in doped antiferromagnets, proposed earlier as a way of describing Kosterlitz-Thouless superconducting gaps at the nodes of the gap of d-wave (high-T_c) superconductors, may also lead to a pseudogap phase, characterised by the formation of (non-superconducting) pairing and the absence of phase coherence. The crucial assumption is again the presence of electrically charged Dirac fermionic excitations (holons) about the points of the (putative) fermi surface in the pertinent phase of the superconductor. We present arguments in support of the r\\^ole of non-perturbative effects (instantons) on the onset of the pseudogap phase. As a means of probing such gauge interactions experimentally, we perform a study of the scaling of the thermal conductivity with an externally-applied magnetic field, in certain effective models involving gauge and/or four-fermion (contact) interactions.

K. Farakos; G. Koutsoumbas; N. E. Mavromatos

1998-05-29T23:59:59.000Z

108

Relaxation time of the order parameter in a high-temperature superconductor  

Science Journals Connector (OSTI)

We present femtosecond time-resolved measurements on the high-Tc superconductor Tl2Ba2Ca2Cu3O10. At temperatures below Tc, we observe a relaxation process which is distinct from the equilibration of hot carriers in the normal state. Our results demonstrate an increasing relaxation rate as the superconducting gap opens. This is consistent with the behavior of conventional metallic superconductors.

G. L. Eesley; J. Heremans; M. S. Meyer; G. L. Doll; S. H. Liou

1990-12-31T23:59:59.000Z

109

Possible Routes to Frictionless Transport of Electronic Fluids in High-Temperature Superconductors  

E-Print Network (OSTI)

Electric-field-driven transport of electronic fluids in metallic glasses as well as three-dimensional amorphous superconductors are investigated by using the verified approach which has been successfully adopted to study the critical transport of glassy solid helium in very low temperature environment. The critical temperatures related to the nearly frictionless transport of electronic fluids were found to be directly relevant to the superconducting temperature of amorphous superconductors after selecting specific activation energies. Our results imply that optimal shear-thinning is an effective way to reach high-temperature charged superfluidity or superconductivity.

Zotin K-H Chu

2009-12-23T23:59:59.000Z

110

Transition temperature and a spatial dependence of the superconducting gap for multilayer high-temperature superconductors  

Science Journals Connector (OSTI)

We derive the expressions for the transition temperature Tc, and the spatial dependence of the superconducting gap for a multilayer high-Tc superconductor composed of groups of tightly spaced planes separated by a larger distance. The results are compared with experiment and provide strong support for an interlayer hopping as the driving force of the large Tc enhancement in multilayered compounds. Our results are universal in the sense that they are valid for an arbitrary pairing potential Vkk? in the CuO2 planes, as well as for both Fermi- and non-Fermi-liquids.

Krzysztof Byczuk and Jozef Spa?ek

1996-01-01T23:59:59.000Z

111

Dynamic stress intensity factors of mode-I crack in high temperature superconductor  

Science Journals Connector (OSTI)

Abstract The coupled magneto-mechanical model is established for the dynamic fracture problem for the high temperature superconductor (HTS). The superconductor EJ constitutive law is characterized by power law model where the critical current density is assumed to depend exponentially on the flux density. The cracked superconductor under dynamic loading are employed to investigate dynamic fracture behavior such as the variation of dynamic stress intensity factors (DSIFs) for different applied magnetic field amplitude, the thickness of HTS, and critical current density. To evaluate \\{DSIFs\\} for a type-II superconductor under alternating magnetic field, the flux pinning induced magnetoelasticity model proposed to evaluate DSIFs, and is implemented in conjunction with finite element method. The results show that the applied magnetic field amplitude, thickness of HTS, and critical current density are three important factors affecting the dynamic fracture behavior of the HTS.

Zhiwen Gao; Youhe Zhou

2013-01-01T23:59:59.000Z

112

Self-assembled monolayer cleaning methods: Towards fabrication of clean high-temperature superconductor nanostructures  

SciTech Connect

Although extensive amounts of research have been carried out on superconductor-normal metal-superconductor (SNS) electronic devices, the fabrication of superconductor SNS devices still remains difficult. Surface modification of high-temperature superconductors could be a way to control the interface of SNS electronic device fabrication. Here, we developed a cleaning method for thin films of high-temperature superconductor surface based on self-assembled monolayers. High-quality c-axis orientated YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (i.e., YBCO) and Y{sub 0.6}Ca{sub 0.4}Ba{sub 1.6}La{sub 0.4}Cu{sub 3}O{sub 7-{delta}} (i.e., TX-YBCO) thin films were deposited by standard laser ablation methods. YBCO/Au/YBCO and TX-YBCO/Au/TX-YBCO planar type junctions were fabricated by photolithography, focused-ion-beam milling, and ex situ sputter depositions. A 40-50 nm nanotrench was ion milled on the thin film by FIB, and a thin gold layer was deposited by an ex situ method on the nanotrench to connect the two separated high-temperature superconductor electrodes. SEM, AFM, and R vs T resistivity measurements were used to compare the corrosion layer formed in the interface of the SNS junctions with the SAM cleaned SNS junction. Evidence here suggests that the SAM cleaning method can be used to remove the degradation layer on the surface of cuprate superconductors. The obtained contact resistivity value (10{sup -8} {omega} cm{sup 2}) for a SNS junction with SAM treatment is comparable with that of SNS junctions fabricated by the in situ methods.

Kim, Sungwook; Chang, In Soon; McDevitt, John T. [Department of Chemistry and Biochemistry, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712-1167 (United States)

2005-04-11T23:59:59.000Z

113

Nonlinear interaction of a ferromagnet with a high-temperature superconductor  

SciTech Connect

The interaction of an Abrikosov vertex with a ferromagnetic substrate is taken into account in the model of a layered high-temperature superconductor (HTSC). The magnetization reversal loops are calculated by the Monte Carlo method for various values of the magnetic moment of the substrate and at various temperatures. The nonlinearity of the interaction of the superconductor with the ferromagnet is demonstrated. The magnetization of HTSC films on magnetic and nonmagnetic substrates is measured. It is found that the ferromagnetism of the substrate strongly affects the shape and magnitude of the magnetization of the HTSC-substrate composite. Experimental data are found to correlate with the results of calculations.

Kashurnikov, V. A., E-mail: kash@pico.mephi.ru; Maksimova, A. N.; Rudnev, I. A., E-mail: IARudnev@mephi.ru; Sotnikova, A. P. [National Research Nuclear University MEPhI (Russian Federation)] [National Research Nuclear University MEPhI (Russian Federation)

2013-03-15T23:59:59.000Z

114

Electronic properties of doped Mott insulators and high temperature superconductors  

E-Print Network (OSTI)

High-temperature superconducting cuprates, which are the quintessential example of a strongly correlated system and the most extensively studied materials after semiconductors, spurred the development in the fields of ...

Ribeiro, Tiago Castro

2005-01-01T23:59:59.000Z

115

Phonon dispersion, phonon specific heat, and Debye temperature of high-temperature superconductors  

Science Journals Connector (OSTI)

A simple model representing the low-frequency acoustical and optical modes of the high-temperature superconductors (HTSCs) leads to a surprisingly realistic representation of the low-temperature specific heats cv(T) and the corresponding Debye temperatures FTHETA(T) of the HTSCs. The model allows us to relate the characteristics and peculiarities of cv(T) and FTHETA(T) directly to various features of the low-frequency phonon dispersion, and it is found that cv and FTHETA can exhibit rather well the identifiable features of phonon anomalies. For instance, a surprising result is that optic Einstein-like modes at ?E=2 THz (h?E/kB=96 K) in our model begin to have an effect at 6 K. This behavior has potentially important consequences for the procedure of separating the phonon contribution from the measured specific heat, in order to obtain the nonphonon specific-heat contributions. Another consequence of the occurrence of these Einstein modes is the presence of low-frequency phonons with large wave vectors, which means that umklapp scattering can begin to play a role at temperatures lower than usually assumed. This, in turn, may require a modification of the customary qualitative picture of the low-temperature electrical and thermal conductivities.

F. W. de Wette and A. D. Kulkarni

1992-12-01T23:59:59.000Z

116

Nonlinear Meissner effect in a high-temperature superconductor  

Science Journals Connector (OSTI)

The lowest nonlinear correction to the penetration depth, i.e., the nonlinear Meissner effect, is calculated and compared to data from high-quality YBa2Cu3O7-? (YBCO) films. The calculation is based on the Green-function formulation of superconductivity, and the data consist of the intermodulation power as function of temperature and circulating power. At a low power level, the calculated temperature dependence compares very well with the data, including the divergence as T?2 at very low temperatures. The calculated power dependence of the nonlinear penetration depth follows the data semiquantitatively and is enhanced due to the d-wave symmetry of the order parameter. These results support the assertion that the origin of nonlinearity in high-quality YBCO films is intrinsic. The analysis also implies that the nonlinear corrections to the penetration depth depend primarily on the total current carried by the strip and thus are insensitive to the edges. The comparison of the present approach with an alternative approach, based on quasiparticle backflow, is discussed.

D. Agassi and D. E. Oates

2005-07-26T23:59:59.000Z

117

In the OSTI Collections: High-Temperature Superconductors | OSTI, US Dept  

Office of Scientific and Technical Information (OSTI)

High-Temperature Superconductors High-Temperature Superconductors Technology Basic Science Progress towards theory References Research Organizations and Scientific Societies Reports Available through OSTI's SciTech Connect Patents available through OSTI's DOepatents Additional References One of the lessons of quantum physics is that any set of subatomic particles bound together by mutual attractions have quite distinct states of relative motion determined by how the particles interact, and that changing the particles' motion from one such state to another requires that their energy and momentum change by appropriate discrete finite amounts. Electrons bound within a metal to the lattice[Wikipedia] of its positive ions[Wikipedia] are no exception. Under ordinary conditions in our usual environment, an electric field applied to the metal can

118

Self-Organized Networks and Lattice Effects in High Temperature Superconductors II: Fermi Arc Anomalies  

E-Print Network (OSTI)

The self-organized dopant percolative filamentary model, entirely orbital in character (no fictive spins), explains the evolution with doping of Fermi arcs observed by ARPES, including the previously unexplained abrupt transitions in quasiparticle strength observed near optimal doping in cuprate high temperature superconductors. Similarly abrupt transitions are also observed in time-resolved picosecond relaxation spectroscopy at 1.5 eV, and these are explained as well, using no new assumptions and no adjustable parameters.

J. C. Phillips

2006-11-07T23:59:59.000Z

119

Electrical-Thermal-Structural Coupled Finite Element Model of High Temperature Superconductor for Resistive Type Fault Current Limiters  

Science Journals Connector (OSTI)

A multi-physics finite element model of high-temperature superconductors (HTS) will be presented in this article. The electrical-thermal model is mainly based on Maxwells equation and basic heat transfer equa...

J. Sheng; Y. Chen; B. Lin; L. Ying; Z. Jin

2014-06-01T23:59:59.000Z

120

Bi 3 + cluster primary ions in SIMS depth profiling of YBaCuO high-temperature superconductor films  

Science Journals Connector (OSTI)

SIMS depth profiling of YBa2Cu3O7 high-temperature superconductor films was performed using a TOF.SIMS-...2Cu3O7 films based on detection of cluster secondary ions.

M. N. Drozdov; Yu. N. Drozdov

2010-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Study of the occupied and unoccupied electronic states of the Y-substituted (Bi,Pb)-2223 high temperature superconductor  

Science Journals Connector (OSTI)

Spectra for the filled and unfilled electronic states of the (Bi,Pb)-2223 high temperature superconductor were recorded by photoemission and fluorescence X-...E F...and at 1.5 eV binding energy wi...

C. Janowitz; A. Mller; A. Krapf; W. Frentrup; H. Dwelk

1997-04-01T23:59:59.000Z

122

IV characteristics and current instability in a high-temperature superconductor with a nonuniform temperature distribution over the cross section  

Science Journals Connector (OSTI)

The effect of a nonuniform temperature distribution in the cross section of a high-temperature superconductor on the formation of its IV...characteristic and the conditions for conservation of a stable distribut...

V. R. Romanovskii

2010-03-01T23:59:59.000Z

123

Low-temperature vortex dynamics in a high-temperature superconductor  

Science Journals Connector (OSTI)

Magnetic-field gradients in the mixed state of a type-II superconductor are studied using Tl205 nuclear magnetic resonance (NMR) on Tl2Ba2Ca2Cu3O10+?. An anomalous peak was observed in the temperature dependence of the transverse relaxation rate at T/Tc?0.25. We attribute this behavior to magnetic-field flucutations from vortex dynamics. We interpret this behavior as a crossover of the principal time scale for vortex dynamics with that of the NMR experiment, approximately 100 ?s. The temperature dependence of this time scale is discussed.

Y.-Q. Song; S. Tripp; W. P. Halperin; L. Tonge; T. J. Marks

1994-12-01T23:59:59.000Z

124

Stripe Domains and First-Order Phase Transition in the Vortex Matter of Anisotropic High-Temperature Superconductors  

E-Print Network (OSTI)

Stripe Domains and First-Order Phase Transition in the Vortex Matter of Anisotropic High-Temperature temperature superconductor and reveal a sharp transition in the state of this phase resulting in regular that can subsequently melt at high temperatures to a vortex liquid, a pinned vortex glassy state that can

Alexei, Koshelev

125

Prospects of High Temperature Superconductors for fusion magnets and power applications  

Science Journals Connector (OSTI)

Abstract During the last few years, progress in the field of second-generation High Temperature Superconductors (HTS) was breathtaking. Industry has taken up production of long length coated REBCO conductors with reduced angular dependency on external magnetic field and excellent critical current density jc. Consequently these REBCO tapes are used more and more in power application. For fusion magnets, high current conductors in the kA range are needed to limit the voltage during fast discharge. Several designs for high current cables using High Temperature Superconductors have been proposed. With the REBCO tape performance at hand, the prospects of fusion magnets based on such high current cables are promising. An operation at 4.5K offers a comfortable temperature margin, more mechanical stability and the possibility to reach even higher fields compared to existing solutions with Nb3Sn which could be interesting with respect to DEMO. After a brief overview of HTS use in power application the paper will give an overview of possible use of HTS material for fusion application. Present high current HTS cable designs are reviewed and the potential using such concepts for future fusion magnets is discussed.

Walter H. Fietz; Christian Barth; Sandra Drotziger; Wilfried Goldacker; Reinhard Heller; Sonja I. Schlachter; Klaus-Peter Weiss

2013-01-01T23:59:59.000Z

126

Phononic pairing glue in cuprates and related high-temperature superconductors  

E-Print Network (OSTI)

Along with some other researches we have realised that the true origin of high-temperature superconductivity should be found in the strong Coulomb repulsion combined with a significant electronphonon interaction. Both interactions are strong (on the order of 1 eV) compared with the low Fermi energy of doped carries which makes the conventional BCS-Eliashberg theory inapplicable in cuprates and related doped insulators. Based on our recent analytical and numerical results I argue that high-temperature superconductivity from repulsion is impossible for any strength of the Coulomb interaction. Major steps of our alternative polaronic theory are outlined starting from the generic Hamiltonian with the unscreened (bare) Coulomb and electron-phonon interactions accounting for critical temperatures of high-temperature superconductors without any adjustable parameters.

A. S. Alexandrov

2011-12-16T23:59:59.000Z

127

High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics  

SciTech Connect

High transition temperature superconductor (HTc)/SrTiO{sub 3} (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (? ? 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (?5 10{sup ?5} defects/?m{sup 2}). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.

Sirena, M.; Flix, L. Avils [Consejo Nacional de Investigaciones Cientficas y Tcnicas, Centro Atmico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina) [Consejo Nacional de Investigaciones Cientficas y Tcnicas, Centro Atmico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Haberkorn, N. [Consejo Nacional de Investigaciones Cientficas y Tcnicas, Centro Atmico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)] [Consejo Nacional de Investigaciones Cientficas y Tcnicas, Centro Atmico Bariloche, CNEA, Bustillo 9500, 8400 Bariloche (Argentina)

2013-07-29T23:59:59.000Z

128

Anomalous peak at low fields in the magnetization versus temperature curve in bulk ceramic high-temperature superconductors  

Science Journals Connector (OSTI)

When a bulk ceramic high-temperature superconductor is cooled in a small field and the magnetic moment of the sample is measured as the sample is warmed, an anomalous peak in the magnetic moment is observed. This peak can be as high as 50% of the low-temperature moment for fields less than 1 Oe, but it rapidly decreases as the magnetic field increases. We show that this anomaly is due to the interrelationship between flux trapping by intergranular weak links and the irreversible flux trapping properties of the superconducting grains as recently described by Hao and Clem.

J. P. Wang and W. C. H. Joiner

1994-07-01T23:59:59.000Z

129

Quantum Skyrmions and the Destruction of Antiferromagnetic Order in High-Temperature Superconductors  

E-Print Network (OSTI)

A continuous field theory which describes the process of doping in high-T$_c$ superconductors of the YBCO-type is presented. It is shown that the introduction of dopants produces the creation of skyrmion topological excitations on the antiferromagnetic background. The energy of these excitations is evaluated. Destruction of the N\\'eel ground state occurs for a critical value $\\delta_C$ of the doping parameter for which the skyrmion energy vanishes. We evaluate this at zero temperature, obtaining $\\delta_C = 0.39 \\pm 0.03$ which agrees with the experimental value $\\delta_C^{exp} = 0.41 \\pm 0.02$.

E. C. Marino

1998-05-27T23:59:59.000Z

130

Nanoscale Interplay of Strain and Doping in a High-Temperature Superconductor  

Science Journals Connector (OSTI)

The highest-temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable that could be harnessed to enhance the superconducting pairing. Here we report the relationship between local doping ...

Ilija Zeljkovic; Jouko Nieminen; Dennis Huang; Tay-Rong Chang; Yang He; Horng-Tay Jeng; Zhijun Xu; Jinsheng Wen; Genda Gu; Hsin Lin; Robert S. Markiewicz; Arun Bansil; Jennifer E. Hoffman

2014-11-03T23:59:59.000Z

131

To Crack or Not to Crack: Strain in High TemperatureSuperconductors  

SciTech Connect

Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the critical current density, and how the irreversiblereduction of the critical current density is dominated by strain inducedcrack formation in the superconductor. From this generic model it becomesclear that magnets using high temperature superconductors will be strainlimited far before the intrinsic magnetic field limitations will beapproached, or possibly even before the magnetic field limitation ofNb3Sn can be surpassed. On a positive note, in a very promising recentresult from NIST on the axial strain dependence of the critical currentdensity in extremely well aligned YBCO, reversible behavior was observed.This result emphasizes the need for further conductor development,specifically for round wire Bi-2212, to generate a wire with a similarreversible dependence on strain. Availability of such a wire will enablethe construction of magnets that can indeed generate fields that farsurpass the limitations of Nb3Sn superconductors.

Godeke, Arno

2007-08-22T23:59:59.000Z

132

Nanoscale strain-induced pair suppression as a vortex-pinning mechanism in high- temperature superconductors  

SciTech Connect

Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centers in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} matrix. Consequently, an outstanding vortex-pinning enhancement correlated to the nanostrain is demonstrated for four types of randomly oriented nanodot, and a unique evolution towards an isotropic vortex-pinning behaviour, even in the effective anisotropy, is achieved as the nanostrain turns isotropic. We suggest a new vortex-pinning mechanism based on the bond-contraction pairing model, where pair formation is quenched under tensile strain, forming new and effective core-pinning regions.

Llordes, Anna [ICMAB, Barcelona, Spain; Palau, A. [ICMAB, Barcelona, Spain; Gazquez, J. [Oak Ridge National Laboratory (ORNL); Coll, M. [ICMAB, Barcelona, Spain; Vlad, R. [ICMAB, Barcelona, Spain; Pomar, A. [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Guzman, Roger [ICMAB, Barcelona, Spain; Ye, S. [ICMAB, Barcelona, Spain; Rouco, V [ICMAB, Barcelona, Spain; Sandiumenge, Felip [ICMAB, Barcelona, Spain; Ricart, Susagna [ICMAB, Barcelona, Spain; Puig, Teresa [ICMAB, Barcelona, Spain; Varela del Arco, Maria [ORNL; Chataigner, D. [CRISMAT, Caen, France; Vanacken, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Gutierrez, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Moschalkov, V. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Deutscher, G. [Tel Aviv University; Magen Dominguez, Cesar [ORNL; Obradors, Xavier [ICMAB, Barcelona, Spain

2012-01-01T23:59:59.000Z

133

Dipolon theory of energy gap parameters in high-temperature superconductors at zero temperature  

Science Journals Connector (OSTI)

Many-body field-theoretic techniques involving dipolon propagator and electron Greens function have been used to derive the general expressions at zero temperature for the renormalized energy gap parameter ?(k?,?), the gap renormalization parameter Z(k?,?), and energy band renormalization parameter ?(k?,?) for momentum k? and frequency ?. The present theory takes into account explicitly the dressed dipolons as mediators of superconductivity, the screened Coulomb repulsion, and nonrigid electron energy bands considering retardation and damping effects and electron-hole asymmetry. For superconducting cuprates it has been shown by symmetry considerations that, in the lowest order approximations, there exists two energy gap parameters, one being antisymmetric (as) with respect to the exchange of the kx and ky components of vector k? and the other being symmetric (s) with respect to the exchange of kx and ky. The antisymmetric solution is a dx2-y2 wave (i.e., ? [cos(kx)-cos(ky)]) which changes sign with respect to the exchange of kx and ky, and the symmetric solution which is highly asymmetric s wave or equivalently, a combination of a symmetric s wave and absolute value of dx2-y2 wave (i.e. ? | [cos(kx)-cos(ky)] | ) which does not change sign with respect to the exchange of kx and ky. Our self-consistent calculations of the real and imaginary parts of ?(k?,?), Z(k?,?), and ?(k?,?) verify the existence of these two (different) solutions and lead to the conclusion that the antisymmetric solution of the gap parameter corresponds to the observed regular (reg) superconducting energy gap whereas the symmetric solution corresponds to the observed pseudo (pse) energy gap. Calculations have been made for Bi2Sr2CaCu2O8+? as well as Bi2Sr2CaCu2O8. Explicitly, for Bi2Sr2CaCu2O8+? superconductor our calculated values of the antisymmetric and symmetric energy gap parameters are ?0as=2215?meV and ?1s=3010?meV with ?0s=1.51.5?meV, where ?as(k?)=?0as [cos(kx)-cos(ky)] and ?s(k?)=?0s+?1s| [cos(kx)-cos(ky)] |, in agreement with the corresponding experimental results ?0reg=16.51.5?meV, ?1pse?24?meV, and ?0pse=-0.52.5?meV. For Bi2Sr2CaCu2O8 superconductor our calculated values of the antisymmetric and the symmetric energy gap parameters are ?0as=2413?meV and ?1s=2915?meV with ?0s?0 which also agree with the corresponding experimental results ?0reg=16.51.5?meV and ?1pse=30-40?meV with ?0pse=-0.52.5?meV. Our calculations also indicate that the bosonic energy relevant to superconductivity in Bi2Sr2CaCu2O8+? superconductor is about 60 meV arising from O1,2 dipolon excitations and that the broad bands observed in optical experiments are due to O1,1, O1,2, and O3 dipolon excitations. Relative contributions from the various dipolon modes have been analyzed. One finds that the symmetric longitudinal modes of oxygen dipolons contribute dominantly in energy gap parameters. The uncertainties in the calculated values of the various parameters are due to uncertainties in the values of the polarizability particularly of oxygen ions, the shielding parameter, the repulsive Coulomb energy, and due to the calculational errors. The origin of the experimentally deduced T* values has been discussed in terms of the present theory which reveals that T* is greater than Tc and that they have the same physical origin.

R. R. Sharma

2001-01-03T23:59:59.000Z

134

Levitation Performance of Bulk High Temperature Superconductor Above the Permanent Magnet Guideway atDifferent Temperatures  

Science Journals Connector (OSTI)

The levitation performance of a high temperature superconducting (HTS) Maglev system was investigated at different temperatures for HTS Maglev vehicle application. Using a cryogenic measurement system, we stud...

Hua Jing; Suyu Wang; Ming Jiang; Jiasu Wang

2010-12-01T23:59:59.000Z

135

Anomalies in the elastic properties of the high?temperature superconductors  

Science Journals Connector (OSTI)

Measurements will be presented of the ultrasonicwavevelocity and attenuation in high?density polycrystalline samples of YBa 2 Cu 3 O 7 at temperatures between 4.2 and 300 K. Both longitudinal and shear wave data were found to be characterized by thermal hysteresis and run?to?run variations. At temperatures below Tc the hysteresis disappeared the elastic constants increased and the attenuation fell. The higher temperature measurements were affected by sample annealing and thermal history and exhibited recovery effects. The pressure dependence of the elastic constants was found to be very large and also to exhibit hysteresis effects. These phenomena are consistent with the suggestion that these ceramics are pseudoplastic solids in which the plasticity is attributed to the mobility of twin boundaries. Recent measurements of Bi?Ca?Sr?Cu?O superconductors will also be presented.

D. P. Almond; G. A. Saunders; E. F. Lambson; A. Al?Kheffaji; M. Cankartaran

1988-01-01T23:59:59.000Z

136

Rigid levitation and suspension of high?temperature superconductors by magnets  

Science Journals Connector (OSTI)

A high?T c superconductor floating freely above a magnet of low symmetry remains rigidly suspended in the air in almost any position and orientation as if stuck in an invisible heap of sand. This striking effect is due to pinning of the magnetic flux lines inside the superconductor and is often overlooked since usually magnets with rotational symmetry are used for levitation. Magnets with rotational symmetry allow for nearly undamped orbiting and rotation of the superconductor about the magnets symmetry axis. But even in this geometry flux?line pinning can be seen since it forces the orbiting superconductor to turn the same face toward the axis. Superconductors with sufficiently strong pinning may even be suspended below a magnet.

E. H. Brandt

1990-01-01T23:59:59.000Z

137

Universal optimal hole-doping concentration in single-layer high-temperature cuprate superconductors  

E-Print Network (OSTI)

We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \\textquotedblleft $dome$\\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates.

T. Honma; P. H. Hor

2006-02-20T23:59:59.000Z

138

An overview of rotating machine systems with high-temperature bulk superconductors  

Science Journals Connector (OSTI)

The paper contains a review of recent advancements in rotating machines with bulk high-temperature superconductors (HTS). The high critical current density of bulk HTS enables us to design rotating machines with a compact configuration in a practical scheme. The development of an axial-gap-type trapped flux synchronous rotating machine together with the systematic research works at the Tokyo University of Marine Science and Technology since 2001 are briefly introduced. Developments in bulk HTS rotating machines in other research groups are also summarized. The key issues of bulk HTS machines, including material progress of bulk HTS, insitu magnetization, and cooling together with AC loss at low-temperature operation are discussed.

Difan Zhou; Mitsuru Izumi; Motohiro Miki; Brice Felder; Tetsuya Ida; Masahiro Kitano

2012-01-01T23:59:59.000Z

139

Experimental investigation of the pairing state of high-temperature superconductors J. Buan,* Branko P. Stojkovic, Nathan Israeloff, A. M. Goldman, C. C. Huang, and Oriol T. Valls  

E-Print Network (OSTI)

Experimental investigation of the pairing state of high-temperature superconductors J. Buan manuscript received 8 April 1996 To address the issue of the pairing state in high-temperature superconductors, four different experimental investigations have been carried out on a single high

Sridhar, Srinivas

140

Finite-temperature phase diagram of nonmagnetic impurities in high-temperature superconductors using a d=3 tJ model with quenched disorder  

E-Print Network (OSTI)

Finite-temperature phase diagram of nonmagnetic impurities in high-temperature superconductors a quenched disordered d=3 tJ Hamiltonian with static vacancies as a model of nonmagnetic impurities in high-Tc materials. Using a renormalization-group approach, we calculate the evolution of the finite-temperature

Thirumalai, Devarajan

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141

Scaling of the superfluid density in high-temperature superconductors C. C. Homes,* S. V. Dordevic, T. Valla, and M. Strongin  

E-Print Network (OSTI)

Scaling of the superfluid density in high-temperature superconductors C. C. Homes,* S. V. Dordevic recently demon- strated that the scaling relation s dcTc may be applied to a large number of high-temperature A scaling relation Nc 4.4 dcTc has been observed in the copper-oxide superconductors, where Nc

Dordevic, Sasha V.

142

VOLUME 83, NUMBER 3 P H Y S I C A L R E V I E W L E T T E R S 19 JULY 1999 Classical Phase Fluctuations in High Temperature Superconductors  

E-Print Network (OSTI)

Fluctuations in High Temperature Superconductors E. W. Carlson,1 S. A. Kivelson,1 V. J. Emery,2 and E of classical phase fluctuations in the high temperature superconductors using a low temperature expansion importance of the two in the high temperature superconductors, since both are anomalous. The low superfluid

Carlson, Erica

143

Performance of a 1 MV A high temperature superconductors-enabled saturable magnetic  

Science Journals Connector (OSTI)

A 1MVA single-phase DC saturated iron core-type fault current limiter (FCL) employing DC coils manufactured from Bi-2223/Ag high temperature superconductor has been designed, constructed, and tested. The device, configured to respond to a fault occurring on either the positive or negative wave cycle, exhibited instantaneous reaction and reset times. It could clip a continuous applied steady state fault current of 1200A, and limited a transient peak fault current of 2200A to the specified current of 100A. The operation of the device did not produce any significant harmonic contribution from the clipping action, as under fault conditions, 99.96% of the harmonic power spectrum of the clipped waveform contributed to the fundamental, and the non-fault inductance of the FCL was

C J Hawley; F Darmann; T P Beales

2005-01-01T23:59:59.000Z

144

10 - Application of high temperature superconductor (HTS) technology in rotating machinery  

Science Journals Connector (OSTI)

Abstract: This chapter discusses the application of high temperature superconductors (HTS) to generators and motors. It first reviews the benefits and rationale for applying HTS technology to generators and motors. It then describes compromises affecting the electromagnetic, mechanical and thermal design for such machines. The different types of machine topology possible, their respective advantages and disadvantages and their Key performance characteristics compared to equivalent conventional machines are then outlined. Issues with developing such machines within an industrial production environment and their installation and operation within a demanding commercial environment are discussed. Challenges facing the design, build, testing and commissioning of such machines are reviewed, with a discussion of future machine and equipment requirements and trends.

R. Fair

2012-01-01T23:59:59.000Z

145

The critical temperature of superconductor and its electronic specific heat  

E-Print Network (OSTI)

It is shown that the critical temperature of the superconductor is related to the Sommerfeld constant, i.e. it is determined by the Fermi energy for I-type superconductors. The estimation of properties of II-type superconductors reveals a somewhat different relation of critical temperature and Fermi energy. Among the high-temperature superconducting ceramics there are the both - I and II - types superconductors.

B. V. Vasiliev

2010-08-09T23:59:59.000Z

146

Magnetic property of a staggered-array undulator using a bulk high-temperature superconductor  

Science Journals Connector (OSTI)

The magnetic field of a staggered-array undulator using a bulk high-temperature superconductor is calculated by analytical and numerical methods. Analytical formulas for the undulator field and the solenoid field required to generate the undulator field are derived from a simple two-dimensional model. The analytical calculation shows the degree of dependence of these fields on the undulator parameters, the generation of a high undulator field proportional to the critical current density of the bulk superconductor, and the good tunability of the undulator field over a wide range of values. The numerical calculation is performed in a three-dimensional geometry by two methods: the center field and energy minimization methods. The latter treats the current distribution inside the bulk, whereas the former neglects it as a natural extension of the analytical model. The calculation also reveals the dependence of the fields on the undulator parameters arising from the current distribution. From the comparison with experimental results, we find that the latter method reproduces the experimental results well, which indicates the importance of the current distribution inside the bulk. Therefore, we derive a semiempirical formula for the required solenoid field by modifying the analytical formula using the numerical results so as to include the effect of the current distribution. The semiempirical formula reproduces the numerical result with an error of 3%. Finally, we estimate the magnetic performance of the undulator as an example of using the formulas and values presented in this paper. The estimation shows that an undulator field twice as large as that of the present in-vacuum undulator but with an equal period and gap can be obtained at a temperature of approximately 2040K, and that deflection parameters (K values) of 1 and 2 can be achieved with periods of 5 and 10mm at approximately 420K.

Ryota Kinjo; Kenta Mishima; Yong-Woon Choi; Mohamed Omer; Kyohei Yoshida; Hani Negm; Konstantin Torgasin; Marie Shibata; Kyohei Shimahashi; Hidekazu Imon; Kensuke Okumura; Motoharu Inukai; Heishun Zen; Toshiteru Kii; Kai Masuda; Kazunobu Nagasaki; Hideaki Ohgaki

2014-02-26T23:59:59.000Z

147

197Au Mssbauer study of a gold-doped YBa2Cu3O7-? high-temperature superconductor  

Science Journals Connector (OSTI)

A high temperature superconductor with the composition YBa2Cu2.9Au0.1O7?? was studied by Mssbauer spectroscopy with the 77 keV gamma rays of197Au, by X-ray diffraction, and by magnetization measurements. The mai...

E. F. Makarov; R. A. Stukan; A. Panfilov; F. E. Wagner; J. Friedl

1994-01-01T23:59:59.000Z

148

B2223 High Temperature Superconductor Wires in Silver Sheath, Filament Diameter Effect on Critical Temperature and Current Density  

Science Journals Connector (OSTI)

B2223 High Temperature Superconductor (HTSC) has been prepared as a pellet by solid state reaction. Then, HTSC wires were fabricated from the prepared superconductor using powder in tube (PIT) method utilizing silver as the tube material. Superconductor powder was packed in the pure silver tube of about 4.5mm diameter, and 50mm long. The prepared wires are of three types; with monofilament MOF, 9 multifilament core (9MF) and 81 filaments core(81MF). Several cycles of mechanical are drawing and rolling process performed to the starting silver tube of 0.4cm diameter and 5cm length and 0.35mm thickness to minimize the filament diameter. The average filament diameter of MoC with 0.7mm SC core which was produce by the first step of drawing, the second 9 MF wire with nine multifilament wire of 0.175mm diameter for each filament,while the 81MFC wire filament diameter was about 25?m for each filament measured with an optical microscope. All the three types of wires were with same outer diameter of 0.9mm. Tc critical temperature for superconductivity is measured for the pellet and wires using four point probes techniques. The critical temperature for the pellet is 110 K, for the monofilament MOF is 112.5 K and for 9 filaments 9MF was found is 117K; while the Tc the 81MF was 119.5K. The critical current density for the 9MF and 81MF wires were found higher than that of the monofilament MOF in spite of the smaller filament diameters of the 9 MF and 81MF. X-ray diffraction pattern shows the high Tc phase of B2223 compounds in addition to low phase, of B2212 compounds. The I-V curves for the three different wires show higher current density for 81 MF wire, while the optical microscope picture shows more grains alignment . MOC and 9 MF wires show misalignment grains.

Akram R. Jabur

2012-01-01T23:59:59.000Z

149

Electric-field dependence of pairing temperature and tunneling in high-temperature superconductors  

Science Journals Connector (OSTI)

Using the Bethe-Salpeter equation including high electric fields, the dependence of the critical temperature of onsetting superconductivity on the applied field is calculated analytically. The critical temperature of pairing is shown to increase with the applied field strength. This is a new field effect and could contribute to the explanation of recent experiments on field-induced superconductivity. From the field dependence of the Bethe-Salpeter equation, the two-particle bound-state solution is obtained as a resonance with a tunneling probability analogous to the WKB solution of a single particle confined in a potential and coupled to an electrical field.

K. Morawetz

2002-11-27T23:59:59.000Z

150

BCS-BEC Crossover: From High Temperature Superconductors to Ultracold Superfluids  

E-Print Network (OSTI)

We review the BCS to Bose Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction $\\Psi_0$. While this ground state has been summarized extensively in the literature, this Review is devoted to less widely discussed issues: understanding the effects of finite temperature, primarily below $T_c$, in a manner consistent with $\\Psi_0$. Our emphasis is on the intersection of two important problems: high $T_c$ superconductivity and superfluidity in ultracold fermionic atomic gases. We address the "pseudogap state" in the copper oxide superconductors from the vantage point of a BCS-BEC crossover scenario, although there is no consensus on the applicability of this scheme to high $T_c$. We argue that it also provides a useful basis for studying atomic gases near the unitary scattering regime; they are most likely in the counterpart pseudogap phase. That is, superconductivity takes place out of a non-Fermi liquid state where preformed, metastable fermion pairs are present at the onset of their Bose condensation. As a microscopic basis for this work, we summarize a variety of $T$-matrix approaches, and assess their theoretical consistency. A close connection with conventional superconducting fluctuation theories is emphasized and exploited.

Qijin Chen; Jelena Stajic; Shina Tan; Kathryn Levin

2004-04-13T23:59:59.000Z

151

Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214  

SciTech Connect

Thermodynamics has been studied systematically for the high temperature cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}}, La-214, in the entire superconductive region from strongly underdoped to strongly overdoped regimes. Magnetization studies with H{parallel}c have been made in order to investigate the changes in free energy of the system as the number of carriers is reduced. Above the superconducting transition temperature, the normal-state magnetization exhibits a two-dimensional Heisenberg antiferromagnetic behavior. Below T{sub c}, magnetization data are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. As the Sr concentration is varied over the wide range from 0.060 (strongly underdoped) to 0.234 (strongly overdoped), the free energy change goes through a maximum at the optimum doped in a manner similar to the T{sub c0} vs. x curve. The density of states, N(0), remains nearly constant in the overdoped and optimum doped regimes, taking a broad maximum around x = 0.188, and then drops abruptly towards zero in the underdoped regime. The La{sub 2-x}Sr{sub x}CuO{sub 4} (La-214) system displays the fluctuating vortex behavior with the characteristic of either 2D or 3D fluctuations as indicated by clearly identifiable crossing points T* close to T{sub c}. The dimensional character of the fluctuations depends on both applied magnetic fields and the density of charge carriers. The dimensional crossover from 2D to 3D occurs in the strongly underdoped regime when the c-axis coherence distance {zeta}{sub c} becomes comparable to the spacing between adjacent CuO{sub 2} layers s at sufficiently high magnetic fields near H{sub c2}.

Yung Moo Huh

2001-05-01T23:59:59.000Z

152

Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214  

SciTech Connect

Thermodynamics has been studied systematically for the high temperature cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}}, La-214, in the entire superconductive region from strongly underdoped to strongly overdoped regimes. Magnetization studies with H {parallel} c have been made in order to investigate the changes in free energy of the system as the number of carriers is reduced. Above the superconducting transition temperature, the normal-state magnetization exhibits a two-dimensional Heisenberg antiferromagnetic behavior. Below T{sub c}, magnetization data are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. As the Sr concentration is varied over the wide range from 0.060 (strongly underdoped) to 0.234 (strongly overdoped), the free energy change goes through a maximum at the optimum doped in a manner similar to the T{sub c0} vs. x curve. The density of states, N(0), remains nearly constant in the overdoped and optimum doped regimes, taking a broad maximum around x = 0.188, and then drops abruptly towards zero in the underdoped regime. The La{sub 2-x}Sr{sub x}CuO{sub 4} (La-214) system displays the fluctuating vortex behavior with the characteristic of either 2D or 3D fluctuations as indicated by clearly identifiable crossing points T* close to T{sub c}. The dimensional character of the fluctuations depends on both applied magnetic fields and the density of charge carriers. The dimensional crossover from 2D to 3D occurs in the strongly underdoped regime when the c-axis coherence distance {xi}{sub c} becomes comparable to the spacing between adjacent CuO{sub 2} layers s at sufficiently high magnetic field near H{sub c2}.

Douglas K. Finnemore

2001-06-25T23:59:59.000Z

153

Investigating the relationship between the superconducting and pseudogap states of the high-temperature superconductor Bi-2201 using scanning tunneling microscopy  

E-Print Network (OSTI)

There is considerable controversy regarding the nature of the relationship between the superconducting and pseudogap states of high-temperature superconductors. Although there exist a large number of theories regarding ...

Boyer, Michael Christopher

2008-01-01T23:59:59.000Z

154

Anomalous low-temperature and high-field magnetoresistance in the organic superconductor -,,BEDT-TTF...2SF5CH2CF2SO3  

E-Print Network (OSTI)

Anomalous low-temperature and high-field magnetoresistance in the organic superconductor -,,BEDT- induced density wave of the open bands at low temperatures and high fields or a possible field induced dimensional 3D Lifshitz-Kosevich theory at low temperatures and high fields. Single crystals of -(BEDT-TTF)2SF

Zuo, Fulin

155

Quadruple perovskites L L Ba2Cu2Ti2O11 as good candidates for high-temperature superconductors: Role of oxygen defects  

E-Print Network (OSTI)

Quadruple perovskites L L Ba2Cu2Ti2O11 as good candidates for high-temperature superconductors in these materials. In the search for new and better high-temperature super- conductors, many new families of layered for the occurrence of high- temperature superconductivity: they contain complete CuO2 planes and a ``charge reservoir

Poeppelmeier, Kenneth R.

156

Numerical simulations of thermomagnetic instability in high-Tc superconductors: Dependence on sweep rate and ambient temperature  

Science Journals Connector (OSTI)

We report the results of numerical simulations of flux jumps on the basis of dynamic process of thermomagnetic interaction to the nonisothermal and nonadiabatic high-Tc superconductors in the regime of thermally activated flux creep when an applied magnetic field is parallel to a slab of the high-Tc superconductors. The simulations for the samples of BiSrCaCuO show that the flux jumps may occur only in the region of low ambient temperature, which is dependent upon the heat contact, and the sweep rate is greater than a lower critical value of about 20G?s and lesser than a large one up to the order of 110T?s. It is found that the predictions of the first flux-jump field Bfj1 are quantitatively in good agreement with the existing experimental data, and the temperature jumps are observed in the superconductors, corresponding to each flux jump in the magnetization loop. When the field sweep rate exceeds the large critical value for the case of the superconductor at 4.2K, the phenomenon of experimental observations without flux jump is successfully predicted by the theoretical simulation, where the thermomagnetic interaction is smoothly circulated at a new dynamic equilibrium state in the temperature region of about 10.616.4K higher than the ambient one, which is mainly dependent on the tradeoff of speeds of the dissipation energy in the slab and the heat removed into the coolant. After that, the sensitivity of the thermomagnetic instability to the parameters, such as critical current density, heat conductivity, heat transfer coefficient, critical geometrical scale, etc. is also discussed.

You-He Zhou and Xiaobin Yang

2006-08-15T23:59:59.000Z

157

Dynamical properties of high-temperature-superconductor granular bridge junctions: Inhomogeneous Josephson-junction-array model  

SciTech Connect

As an attempt to understand the dynamical behavior of the high-temperature-superconductor (HTSC) granular bridge junction, we model the granular HTSC bridge junction consisting of many small grains inside by an inhomogeneous Josephson junction array, i.e., randomly arranged Josephson junction arrays (JJA). To describe randomly distributed critical currents between the grains inside the HTSC granular bridge junction, we chose various possible configurations in {l_brace}{ital I}{sub {ital ij}}{sup {ital c}}{r_brace} and {l_brace}{ital R}{sub {ital ij}}{r_brace} for the one-dimensional (1D) and 2D inhomogeneous Josephson junctions, and calculated the current-voltage ({ital IV}) characteristics and self-radiation spectral densities of the 1D and 2D inhomogeneous Josephson junctions. As a result, depending upon the distribution of critical currents and shunted resistances, it is found that there are large variations of {ital IV} characteristics. In contrast to the appearance of giant Shapiro steps in the regular ordered array, such Shapiro steps disappear in the case of the disordered JJA due to the increased randomness in the distribution of critical currents. On the contrary, however, when there exists a correlation between critical currents and resistances, i.e., a constant Josephson voltage, {ital I}{sub {ital ij}}{sup {ital c}}{ital R}{sub {ital ij}}={ital V}{sub {ital J}} (constant), the fundamental Shapiro step emerges despite the disordered distribution of {ital I}{sub {ital ij}}{sup {ital c}}. The relevance of this model to the HTSC granular bridge junctions is discussed. In particular, experimentally observed dynamical behaviors of the HTSC granular bridge junctions are shown to be closely related to the case of the correlated distribution with constant Josephson voltage. {copyright} {ital 1996 The American Physical Society.}

Lee, J.; Lee, S.; Yu, J.; Park, G. [Department of Physics, Sogang University, Seoul 121-742 (Korea)] [Department of Physics, Sogang University, Seoul 121-742 (Korea)

1996-02-01T23:59:59.000Z

158

Theoretical studies on phonon spectra of high temperature superconductor YBaCuFeO5  

Science Journals Connector (OSTI)

The role of superconductivity can be understood by the assignments of spectral features to lattice vibrations. Raman and infrared studies have contributed significantly to the explication of high Tc superconductor mechanics. In the present work, normal coordinate calculations have been carried out to study the vibrational analysis of perovskite like antiferromagnetic compound YBaCuFeO5. It is important to have knowledge of phonon frequency spectrum for the interpretation of physical properties such as thermal, elastic, infrared, etc., which can be achieved by means of theoretical models of lattice dynamics. A three-body force shell model (TBSM) which takes into account many body interactions is applied to study the lattice dynamics of high Tc superconductors YBaCuFeO5. For the interpretation of infrared and Raman spectrum, the phonon frequencies at the centre of Brillouin zone are presented and vibrational assignments are discussed. The calculations yield not only the phonon frequencies at the centre, but also throughout the Brillouin zone.

A. Punitha; Sujin P. Jose; S. Mohan

2012-01-01T23:59:59.000Z

159

Magnetic structure of the high temperature superconductor Gd{sub 1x}Th{sub x}FeAsO  

SciTech Connect

The magnetic structure of the high temperature superconductor Gd{sub 1x}Th{sub x}FeAsO (x?=?0, 0.25) has been determined by neutron powder diffraction. The Gd moments were found to order at T{sub N} ? 4?K and to lie in the basal plane, and form alternating ferromagnetic sheets along the c-axis. The orientation of the gadolinium moments in both the doped and undoped compounds has been confirmed using {sup 155}Gd Mssbauer spectroscopy.

Lee-Hone, N. R.; Ryan, D. H., E-mail: dhryan@physics.mcgill.ca [Physics Department and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Cadogan, J. M. [School of Physical, Environmental and Mathematical Sciences, UNSW Canberra at the Australian Defence Force Academy, Canberra, BC 2610 (Australia); Sun, Y. L.; Cao, G. H. [Department of Physics, Zhejiang University, Hangzhou 310027 (China)

2014-05-07T23:59:59.000Z

160

Nanoscale strain-induced pair suppression as a source of vortex pinning in high-temperature superconductors  

SciTech Connect

Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centres in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} matrix. Consequently, an outstanding vortex-pinning enhancement correlated to the nanostrain is demonstrated for four types of randomly oriented nanodot, and a unique evolution towards an isotropic vortex-pinning behaviour, even in the effective anisotropy, is achieved as the nanostrain turns isotropic. We suggest a new vortex-pinning mechanism based on the bond-contraction pairing model, where pair formation is quenched under tensile strain, forming new and effective core-pinning regions.

Llordes, A. [ICMAB, Barcelona, Spain; Palau, A. [ICMAB, Barcelona, Spain; Vlad, R. [ICMAB, Barcelona, Spain; Pomar, A. [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Guzman, Roger [ICMAB, Barcelona, Spain; Gazquez Alabart, Jaume [ORNL; Varela del Arco, Maria [ORNL; Sandiumenge, Felip [ICMAB, Barcelona, Spain; Ricart, Susagna [ICMAB, Barcelona, Spain; Puig, Teresa [ICMAB, Barcelona, Spain; Chataigner, D. [CRISMAT, Caen, France; Vanacken, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Gutierrez, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Deutscher, G. [Tel Aviv University; Moschalkov, V. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Obradors, Xavier [ICMAB, Barcelona, Spain

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Theory of Quantum Oscillations in Cuprate Superconductors  

E-Print Network (OSTI)

High Temperature Cuprate Superconductors . . . . . . . . . . . . . . . . . .the underdoped high temperature superconductor YBa 2 Cu 3 Oorder in the high-temperature superconductor yba 2 cu 3 o

Eun, Jonghyoun

2012-01-01T23:59:59.000Z

162

Phase structure of an Abelian two-Higgs model and high temperature superconductors  

E-Print Network (OSTI)

We study the phase structure of a three dimensional Abelian Higgs model with singly- and doubly-charged scalar fields coupled to a compact Abelian gauge field. The model is pretending to describe systems of strongly correlated electrons such as high-Tc superconductivity in overdoped regime and exotic phases supporting excitations with fractionalized quantum numbers. We identify the Fermi liquid, the spin gap, the superconductor and the strange metallic phases in which densities and properties of holon and spinon vortices and monopoles are explored. The phase diagram in the 3D coupling space is predicted. We show that at sufficiently strong gauge coupling the spinon-pair and holon condensation transitions merge together and become, unexpectedly, first order.

M. N. Chernodub; E. -M. Ilgenfritz; A. Schiller

2005-12-06T23:59:59.000Z

163

Experimental method to find weak bond distribution functions in a high-temperature superconductor  

Science Journals Connector (OSTI)

A simple phenomenological model of a weakly bonded superconductor is suggested. The model considers the transition from a single weak dangling bond to a disruptive two-dimensional structure in taking the IV char...

M. A. Vasyutin

2013-11-01T23:59:59.000Z

164

Development of High Temperature Superconductor Coated Metal Fiber and Multifilamentary Wire  

Science Journals Connector (OSTI)

Long superconductor fibers have been continuously produced by electrophoretically...2Cu3O7?x...powder onto a metal substrate fiber and sintering, then eletrophoreticaly depositing silver and sintering. After coll...

L. D. Woolf; F. E. Elsner; W. A. Raggio; S. S. Pak

1992-01-01T23:59:59.000Z

165

Isotope effect on the superfluid density in conventional and high-temperature superconductors  

E-Print Network (OSTI)

We investigate the isotope effect on the London penetration depth of a superconductor which measures nS/m* [n subscript s / m superscript asterisk], the ratio of superfluid density to effective mass. We use a simplified ...

Serbyn, Maksym

166

Model for local para-Cooperons possibly relevant for high-temperature superconductors  

SciTech Connect

We examine the superconductivity analog of the local paramagnon concept in itinerant magnetism. This local-pairing model involves critical temperatures which are /ital not/ exponential, in contrast with the usual BCS ones. Interesting consequences are expected, in particular concerning the possibility of reaching high superconducting temperatures.

Beal-Monod, M. T.

1989-06-01T23:59:59.000Z

167

Prototype of a microwave generator with a high-temperature superconductor disk resonator in a feedback circuit with a low phase-noise level  

Science Journals Connector (OSTI)

Phase noise of a prototype of microwave generator with a disk resonator based on high-temperature superconductor (HTSC) Y1Ba2Cu3O7 ? ?...films in the feedback circuit has been measured for the first time. The dis...

A. E. Parafin; D. V. Masterov; S. A. Pavlov; M. A. Krevskii

2013-12-01T23:59:59.000Z

168

Sum rules and energy scales in the high-temperature superconductor YBa2Cu3O6x C. C. Homes* and S. V. Dordevic  

E-Print Network (OSTI)

Sum rules and energy scales in the high-temperature superconductor YBa2Cu3O6¿x C. C. Homes* and S, the energy scale c required to recover the full strength of the superfluid s in the two materials and the relevant energy scale for s in a BCS material should be twice the energy gap. The FGT sum rule

Homes, Christopher C.

169

Method and apparatus for cooling high temperature superconductors with neon-nitrogen mixtures  

DOE Patents (OSTI)

Apparatus and methods for cooling high temperature superconducting materials (HTSC) to superconductive temperatures within the range of 27.degree. K. to 77.degree. K. using a mixed refrigerant consisting of liquefied neon and nitrogen containing up to about ten mole percent neon by contacting and surrounding the HTSC material with the mixed refrigerant so that free convection or forced flow convection heat transfer can be effected.

Laverman, Royce J. (South Holland, IL); Lai, Ban-Yen (Hinsdale, IL)

1993-01-01T23:59:59.000Z

170

Energy gaps in the failed high-Tc superconductor La1:875Ba0:125CuO4  

E-Print Network (OSTI)

B. The pseudogap i n high-temperature superconductors: A ntwo gaps of the high-temperature superconductor B i S r C u

He, R.-H.

2012-01-01T23:59:59.000Z

171

Investigation of relaxation phenomena in high-temperature superconductors HoBa2Cu3O7-d at the action of pulsed magnetic fields  

E-Print Network (OSTI)

It is used the mechanical method of Abrikosov vortex stimulated dynamics investigation in superconductors. With its help it was studied relaxation phenomena in vortex matter of high-temperature superconductors. It established that pulsed magnetic fields change the course of relaxation processes taking place in vortex matter. The study of the influence of magnetic pulses differing by their durations and amplitudes on vortex system of isotropic high-temperature superconductors system HoBa2Cu3O7-d showed the presence of threshold phenomena. The small duration pulses does not change the course of relaxation processes taking place in vortex matter. When the duration of pulses exceeds some critical value (threshold), then their influence change the course of relaxation process which is revealed by stepwise change of relaxing mechanical moment . These investigations showed that the time for formatting of Abrikosov vortex lattice in HoBa2Cu3O7-d is of the order of 20 microsec. which on the order of value exceeds the time necessary for formation of a single vortex observed in type II superconductors.

J. G. Chigvinadze; J. V. Acrivos; S. M. Ashimov; A. A. Iashvili; T. V. Machaidze; Th. Wolf

2007-04-03T23:59:59.000Z

172

Interaction of magnetic field and magnetic history in high-temperature superconductors  

Science Journals Connector (OSTI)

Yttrium barium copper oxide (YBCO) coated conductors are now the most promising high-temperature superconducting tapes in terms of current capacity and price. One form of these conductors utilizes YBCO films on NiW metallic tapes and is being considered for a number of power engineering applications. In these applications the conductor will carry an ac current leading to energy losses which are the focus of significant technical and experimental efforts. Our measurements of the ac losses of YBCO/NiW conductors carrying ac currents in applied dc magnetic fields have revealed a complex interaction between the magnetic materials present the geometry of the conductor the ac and dc magnetic fields and the electromagnetic history of the sample. The investigation of this interaction is the main subject of this paper.

Francesco Grilli; Stephen P. Ashworth; Leonardo Civale

2007-01-01T23:59:59.000Z

173

Self-Organized Networks and Lattice Effects in High Temperature Superconductors III: Dopant Internal Structure  

E-Print Network (OSTI)

The self-organized dopant percolative filamentary model, entirely orbital in character (no fictive spins), predicted the existence and even the ~ 3 nm diameters of gap nanodomains (discovered by STM) that amazed almost all theorists in this field. Here it explores the self-consistent and self-limiting coupling between dopant sites and gap character. It explains precursive magnetic effects and shows that they are caused by dopant ordering into loops at an onset temperature of order 2Tc. The ordered coupling of these loops by filamentary connectors is reflected by Debye-Waller factors, and it apparently leads to HTSC. The model also resolves the mystery of the vanishing isotope effect, and it explains the origin of the high-energy "waterfall" recently discovered by ARPES, as well as some overlooked infrared anomalies.

J. C. Phillips

2006-11-08T23:59:59.000Z

174

High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O  

SciTech Connect

A process is disclosed for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO[sub 3] crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O[sub 3], followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry. 8 figs.

Ginley, D.S.; Hietala, V.M.; Hohenwarter, G.K.G.; Martens, J.S.; Plut, T.A.; Tigges, C.P.; Vawter, G.A.; Zipperian, T.E.

1994-10-25T23:59:59.000Z

175

High temperature superconductor step-edge Josephson junctions using Ti-Ca-Ba-Cu-O  

SciTech Connect

A process for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO.sub.3 crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O.sub.3, followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry.

Ginley, David S. (Evergreen, CO); Hietala, Vincent M. (Placitas, NM); Hohenwarter, Gert K. G. (Madison, WI); Martens, Jon S. (Sunnyvale, CA); Plut, Thomas A. (Albuquerque, NM); Tigges, Chris P. (Albuquerque, NM); Vawter, Gregory A. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

1994-10-25T23:59:59.000Z

176

Spectroscopy of the layered high-temperature superconductors and their collective plasmon modesa model for phonon- and plasmon-induced pairing  

Science Journals Connector (OSTI)

The recently discovered layered copper oxide high-Tc superconductors are discussed as models of a layered electron gas with highly anisotropic collective modes (layer plasmons). Our...

Kresin, V Z; Morawitz, H

1989-01-01T23:59:59.000Z

177

Microwave characteristics of the high temperature superconductor YBa?Cu?O??[delta  

E-Print Network (OSTI)

) Figure 24. Reactance of a 6. 5 mm YBaCuO strip in Ku-band waveguide 25. Temperature inside the waveguide as a function of time 26. Ss, at 30 second intervals after immersion in LNs 27. Sqq at 1 minute intervals Comparison of surface resistance data.... This includes both theoretical and experimental efforts. While the theory that explains the mechanism causing superconductivity in these materials has yet to surface, the physical properties and potential applications are being investigated at a rapid pace...

Skrehot, Michael Kevin

2012-06-07T23:59:59.000Z

178

Thin film growth and characterization of the electron- doped superconductor Sm?2?-x?C?ex?CuO?4?-?y  

E-Print Network (OSTI)

Fluctuations in High-Temperature Superconductors (Plenumdiscovery of high temperature superconductors (high-T c ) in18]. These new high temperature superconductors belong to a

Scanderbeg, Daniel Joseph

2007-01-01T23:59:59.000Z

179

Full Fermi Surface of a High Temperature Superconductor Revealed by Angular Magnetoresistance Oscillations  

Science Journals Connector (OSTI)

We report the first observation of polar angular magnetoresistance oscillations in the high-T c cuprate Tl2Ba2CuO6. These measurements establish the existence of a coherent three-dimensional Fermi s...

N. E. Hussey; M. Abdel-Jawad; A. Carrington

2005-01-01T23:59:59.000Z

180

2D and 3D percolation in high-temperature superconductors  

Science Journals Connector (OSTI)

A quantitative model is presented for the high critical current densities (Jc) supported by superconducting materials with uniaxial alignment, such as c-axis textured Bi-Sr-Ca-Cu-O tapes. Current follows percolative paths across small-angle grain boundaries. Because jc is low for intragranular conduction parallel to the c axis, the 3D flow required for percolation is produced by conduction perpendicular to the c axis in tilted grains. For optimized microstructures, Jc ranging from 3 to 30 % of the intragranular value is predicted for percolation across small-angle grain boundaries with misorientations below 10 and 20, respectively. 1996 The American Physical Society.

E. D. Specht; A. Goyal; D. M. Kroeger

1996-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Highly oxidized superconductors  

DOE Patents (OSTI)

Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known synthesis in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

Morris, D.E.

1994-09-20T23:59:59.000Z

182

Ambient-temperature superconductor symetrical metal-dihalide bis-(ethylenedithio)-tetrathiafulvalene compounds  

DOE Patents (OSTI)

A new class of organic superconductors having the formula (ET).sub.2 MX.sub.2 wherein ET represents bis(ethylenedithio)-tetrathiafulvalene, M is a metal such as Au, Ag, In, Tl, Rb, Pd and the like and X is a halide. The superconductor (ET).sub.2 AuI.sub.2 exhibits a transition temperature of 5 K. which is high for organic superconductors.

Williams, Jack M. (Downers Grove, IL); Wang, Hsien-Hau (Willowbrook, IL); Beno, Mark A. (Woodridge, IL)

1987-01-01T23:59:59.000Z

183

Power System Feedback from High-Tc Superconductor Shielded Core Fault Current Limiter  

Science Journals Connector (OSTI)

The shielded core fault current limiter is attractive with high critical temperature superconductors. ... acts during normal operation as an ideally shorted current transformer; the secondary superconducting loop...

J. Gerhold

1998-01-01T23:59:59.000Z

184

GulyaevBleustein Waves in a Layered Structure of Piezoelectric Periodic Granular High-Temperature Superconductor Structure  

Science Journals Connector (OSTI)

Bragg's interactions of GulyaevBleustein surface waves with a periodic granular high-temperature superconducting medium are studied. Dispersion equations describing the characteristics of surface acoustoelect...

V. A. Krakovskii

2001-06-01T23:59:59.000Z

185

Scattering from Incipient Stripe Order in the High-temperature Superconductor Bi2Sr2CaCu2O8  

SciTech Connect

Recently, we have used spectroscopic mapping with a scanning tunneling microscope to probe modulations of the electronic density of states in single crystals of the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212) as a function of temperature [C.V. Parker et al. Nature (London) 468 677 (2010)]. These measurements showed Cu-O bond-oriented modulations that form below the pseudogap temperature with a temperature-dependent energy dispersion displaying different behaviors in the superconducting and pseudogap states. Here we demonstrate that quasiparticle scattering from impurities does not capture the experimentally observed energy and temperature dependence of these modulations. Instead, a model of scattering of quasiparticles from short-range stripe order, with periodicity near four lattice constants (4a), reproduces the experimentally observed energy dispersion of the bond-oriented modulations and its temperature dependence across the superconducting critical temperature T{sub c}. The present study confirms the existence of short-range stripe order in Bi-2212.

da Silva Neto E. H.; Wen J.; Parker, C.V.; Aynajian, P.; Pushp, A.; Yazdani, A.; Xu, Z.; Gu, G.

2012-03-01T23:59:59.000Z

186

The algebraic spin liquid of a possible model description for the normal state of underdoped high temperature superconductors  

E-Print Network (OSTI)

16 years and counting ... In 1986 Bednorz and Muller discovered the layered perovskite structure (La - Ba)2Cu04 which showed the phenomenon of superconductivity at the unprecedented high temperature of Tc = 33 K. In the ...

Rantner, Walter, 1973-

2002-01-01T23:59:59.000Z

187

Low-Temperature Synthesis Routes to Intermetallic Superconductors  

SciTech Connect

Over the past few years, our group has gained expertise at developing low-temperature solution-based synthetic pathways to complex nanoscale solids, with particular emphasis on nanocrystalline intermetallic compounds. Our synthetic capabilities are providing tools to reproducibly generate intermetallic nanostructures with simultaneous control over crystal structure, composition, and morphology. This DOE-funded project aims to expand these capabilities to intermetallic superconductors. This could represent an important addition to the tools that are available for the synthesis and processing of intermetallic superconductors, which traditionally utilize high-temperature, high-pressure, thin film, or gas-phase vacuum deposition methods. Our current knowledge of intermetallic superconductors suggests that significant enhancements could result from the inherent benefits of low-temperature solution synthesis, e.g. metastable phase formation, control over nanoscale morphology to facilitate size-dependent property studies, robust and inexpensive processability, low-temperature annealing and consolidation, and impurity incorporation (for doping, stoichiometry control, flux pinning, and improving the critical fields). Our focus is on understanding the superconducting properties as a function of synthetic route, crystal structure, crystallite size, and morphology, and developing the synthetic tools necessary to accomplish this. This research program can currently be divided into two classes of superconducting materials: intermetallics (transition metal/post transition metal) and metal carbides/borides. Both involve the development and exploitation of low-temperature synthesis routes followed by detailed characterization of structures and properties, with the goal of understanding how the synthetic pathways influence key superconducting properties of selected target materials. Because of the low-temperature methods used to synthesize them and the nanocrystalline morphologies of many of the products, the superconductors and their nanocrystalline precursors are potentially amenable to inexpensive and large-scale solution-based processing into wires, coatings, films, and templated or patterned structures with nanoscale and microscale features. Also, because of the new synthetic variables that play a key role in the low-temperature formation of intermetallics, the possibility exists to discover new superconductors.

Schaak, Raymond E

2008-01-08T23:59:59.000Z

188

Structural phase transitions in EuFe[subscript 2]As[subscript 2] superconductor at low temperatures and high pressures  

SciTech Connect

The crystal structure of EuFe{sub 2}As{sub 2} has been studied up to a pressure of 35 GPa and down to a temperature of 8 K using temperature dependent x-ray diffraction in a diamond anvil cell at a synchrotron source. At 4.3 GPa, we have detected a structural phase transition from a high temperature tetragonal phase with I4/mmm space group to a low temperature orthorhombic phase with Fmmm space group around 120 K. With the application of pressure at a low temperature of 10 K, the orthorhombic phase is suppressed and a phase change to a collapsed tetragonal phase with I4/mmm space group is observed at 11 GPa. This collapsed tetragonal phase is similar to the one observed at ambient temperature and pressure above 8.5 GPa. We have shown that the collapsed tetragonal phase of EuFe{sub 2}As{sub 2} has the same pressure-volume (P-V) equation of state at ambient temperature and at 10 K, implying that the high pressure phase of EuFe{sub 2}As{sub 2} has a negligible thermal expansion coefficient.

Uhoya, Walter O.; Tsoi, Georgiy M.; Vohra, Yogesh K.; McGuire, Michael A.; Sefat, Athena S. (UAB); (ORNL)

2011-09-20T23:59:59.000Z

189

'Magnetoscan': a modified Hall probe scanning technique for the detection of inhomogeneities in bulk high temperature superconductors  

Science Journals Connector (OSTI)

We present a novel technique for the investigation of local variations of the critical current density in large bulk superconductors. In contrast to the usual Hall probe scanning technique, the sample is not magnetized as a whole before the scan, but locally by a small permanent magnet, which is fixed near the Hall probe, during the scanning process. The resulting signal can be interpreted as a qualitative measure of the local shielding currents flowing at the surface.

M Eisterer; S Haindl; T Wojcik; H W Weber

2003-01-01T23:59:59.000Z

190

Bridging the Gaps of High-Tc Superconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

Bridging the Gaps of High-Tc Bridging the Gaps of High-Tc Superconductor Since the discovery of high-temperature superconductor by Bednorz and Müller in 1986, this field has become one of the most important research topics in solid state physics. In the past 20 years many unconventional properties have been discovered in this new class of materials. These have challenged our conventional wisdom and driven the development of many novel theories. Among these discoveries, the most mysterious is probably the pseudogap phenomena: it has been observed that there is an energy gap above the superconducting transition temperature (TC) that persists over a wide range of temperatures and chemical compositions [1]. This peculiar behavior appears to be very different from a conventional superconductor. Here the electrons form so-called "Cooper pairs", which manifests itself as an energy gap in many spectroscopic measurements. This energy gap, known as superconducting gap, appears only below TC where the electrical resistance also vanishes (hence the name 'superconductor'). This important difference has stimulated lots of debate in the search of understanding high-TC superconductivity on questions such as: "What is the pseudogap?" and "What is its relation to superconducting gap and superconductivity at high temperature?"

191

Controlling the Carrier Concentration of the High-Temperature Superconductor Bi2Sr2CaCu2O8+? in Angle-resolved Photoemission Spectroscopy Experiments  

SciTech Connect

We study the variation of the electronic properties at the surface of a high-temperature superconductor as a function of vacuum conditions in angle-resolved photoemission spectroscopy experiments. Normally, under inadequate ultrahigh vacuum (UHV) conditions the carrier concentration of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi2212) increases with time due to the absorption of oxygen from CO{sub 2}/CO molecules that are prime contaminants present in UHV systems. We find that in an optimal vacuum environment at low temperatures, the surface of Bi2212 is quite stable (the carrier concentration remains constant); however at elevated temperatures the carrier concentration decreases due to the loss of oxygen atoms from the Bi-O layer. These two effects can be used to control the carrier concentration in situ. Our finding opens the possibility of studying the electronic properties of the cuprates as a function of doping across the phase diagram on the same surface of sample (i.e., with the same impurities and nondopant defects). We envision that this method could be utilized in other surface sensitive techniques such as scanning tunneling microscopy/spectroscopy.

Palczewski, A.D.; Wen, J.; Kondo, T.; Xu, G.Z.J., Gu, G; Kaminski, A.

2010-03-19T23:59:59.000Z

192

A High Temperature Superconductor (HTSC) Hot Electron (HE) THz Heterodyne Thermal Sensor (HTS): Computational Analysis of Conversion Gain in  

Science Journals Connector (OSTI)

The solution of the two temperature (electron and phonon) heat transfer equations, for nonequilibrium elctronphonon cooling processes happening between electrons, sensor lattice, and the substrate system, is ...

M. M. Kaila

2002-06-01T23:59:59.000Z

193

119Sn Mssbauer study of high-temperature superconductor YBa2Cu3O7?y doped with Sn  

Science Journals Connector (OSTI)

All samples were prepared at the same condition: prefired at 900C for 10 hours in oxygen and sintered at 1000C for 30 hour in oxygen. The zero resistance temperature decreased with increasing Sn content.

Jin Mingzhi; Li Haibo; Jin Douying; Liu Xuewu

1990-07-01T23:59:59.000Z

194

High Field Magnet R&D in the USA  

E-Print Network (OSTI)

aI. , "Status of High Temperature Superconductor Magnet R&Dmention High Temperature Superconductor (I-ITS). Though

Gourlay, S.A.

2011-01-01T23:59:59.000Z

195

Low-Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt3Si D. P. Young, M. Moldovan, X. S. Wu, and P. W. Adams  

E-Print Network (OSTI)

Low-Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt3Si D. P. Young, M high upper critical field Bc2 4­5 T, the low-temperature susceptibility 0 is quite fragile-II superconductor, the zero temperature susceptibility obeys a power-law field depen- dence which is inconsistent

Adams, Philip W.

196

High Temperature Superconducting Fault Current Limiter for Utility Applications  

Science Journals Connector (OSTI)

One of the most near term High Temperature Superconductor (HTS) applications is the Fault Current Limiter (FCL). It is a device that...

E. M. W. Leung; G. W. Albert; M. Dew

1997-01-01T23:59:59.000Z

197

Two-band model of a high-temperature superconductor and the dependence of the critical temperature of transition on the parameters of the model  

Science Journals Connector (OSTI)

Within the limit of weak coupling with allowance for the level of hybridization and polarization of states, dependences of the critical temperature of the superconducting transition on the concentration of car...

L. G. Zhidkov; A. G. Tretyakov; T. N. Adrianova

2006-07-01T23:59:59.000Z

198

Argonne superconductor technology licensed  

Science Journals Connector (OSTI)

Argonne superconductor technology licensed ... American Superconductor Corp. of Cambridge, Mass., has obtained the exclusive rights to develop and market high-temperature superconductor technology developed at the Department of Energy's Argonne National Laboratory. ... The Argonne technology produces superconducting ceramic coatings by oxidizing an appropriate metallic precursor. ...

RON DAGANI

1988-10-17T23:59:59.000Z

199

On the Search for Higher Temperature Superconductors for Power Grid Applications  

E-Print Network (OSTI)

On the Search for Higher Temperature Superconductors for Power Grid Applications A. P. Malozemoff have enabled a breakthrough in superconductor power grid applications. Based on growing commercial for power grid applications. In this perspective, superconductors such as YBCO constitute a good compromise

Paris-Sud 11, Université de

200

205Tl NMR observation of vortex lattice formation in the high temperature superconductor Tl2Ba2CuO6  

Science Journals Connector (OSTI)

We report on the asymmetric field distribution of the triangular vortex lattice in the superconductor Tl2Ba2CuO6 as observed by205Tl NMR atB a =4.26 T. A penetra...

M. Mehring; F. Hentsch; Hj. Mattausch

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Nonlinear ultrafast dynamics of high temperature YBa[subscript 2]Cu[subscript 3]O[subscript 7-?] superconductors probed with THz pump / THz probe spectroscopy  

E-Print Network (OSTI)

High power THz pulses induce near transparency in superconductive YBCO thin films below the critical temperature. THz pump/THz probe measurements reveal a decay of the induced transparency on the time scale of a few picoseconds.

Grady, N. K.

202

Influence of a constant magnetic field on the dispersion of surface magnetostatic waves in a structure consisting of ferrite and granular high-temperature superconductor  

Science Journals Connector (OSTI)

The dispersional properties of a surface magnetostatic wave (MSW) in a laminar structure consisting of ferrite film and a high-temperature superconducting (HTSC) layer are studied in detail. The propagation of...

V. A. Krakovskii; E. S. Kovalenko

1996-06-01T23:59:59.000Z

203

Synthesis of highly phase pure BSCCO superconductors  

DOE Patents (OSTI)

An article and method of manufacture of (Bi, Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor.

Dorris, Stephen E. (La Grange Park, IL); Poeppel, Roger B. (Glen Ellyn, IL); Prorok, Barton C. (Harrisville, PA); Lanagan, Michael T. (Woodridge, IL); Maroni, Victor A. (Naperville, IL)

1995-01-01T23:59:59.000Z

204

Synthesis of highly phase pure BSCCO superconductors  

DOE Patents (OSTI)

An article and method of manufacture (Bi, Pb)-Sr-Ca-Cu-O superconductor are disclosed. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor. 5 figs.

Dorris, S.E.; Poeppel, R.B.; Prorok, B.C.; Lanagan, M.T.; Maroni, V.A.

1995-11-21T23:59:59.000Z

205

Low Temperature Stage in Electron Microscope for Study on Superconductors  

Science Journals Connector (OSTI)

......superconductors. The elementary magnetic property of superconductors...of the superconducting resistance-transition must be connected...stage to be movable. 2. Electric lead wires Electric lead...experiment by measuring the resistance of the specimen by the......

Tomoyuki MIYAZAKI; Ryozo AOKI; Bunjyu SHINOZAKI; Shigeru YAMASHITA

1980-01-01T23:59:59.000Z

206

Frustrated phase separation and high temperature superconductivity  

SciTech Connect

A dilute system of neutral holes in an antiferromagnet separates into a hole-rich and a hole-poor phase. The phase separation is frustrated by long-range Coulomb interactions but, provided the dielectric constant is sufficiently large, there remain large-amplitude low-energy fluctuations in the hole density at intermediate length scales. The extensive experimental evidence showing that this behavior giver, a reasonable picture of high temperature superconductors is surveyed. Further, it is shown that the scattering of mobile holes from the local density fluctuations may account for the anomalous normal-state properties of high temperature superconductors and also provide the mechanism of pairing.

Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

1992-09-01T23:59:59.000Z

207

Frustrated phase separation and high temperature superconductivity  

SciTech Connect

A dilute system of neutral holes in an antiferromagnet separates into a hole-rich and a hole-poor phase. The phase separation is frustrated by long-range Coulomb interactions but, provided the dielectric constant is sufficiently large, there remain large-amplitude low-energy fluctuations in the hole density at intermediate length scales. The extensive experimental evidence showing that this behavior giver, a reasonable picture of high temperature superconductors is surveyed. Further, it is shown that the scattering of mobile holes from the local density fluctuations may account for the anomalous normal-state properties of high temperature superconductors and also provide the mechanism of pairing.

Emery, V.J. (Brookhaven National Lab., Upton, NY (United States)); Kivelson, S.A. (California Univ., Los Angeles, CA (United States). Dept. of Physics)

1992-01-01T23:59:59.000Z

208

Magneto-optical studies of magnetization processes in high-Tc superconductors structure.  

SciTech Connect

Magneto-optical imaging is a powerful tool for nondestructive quality control and scientific research through visualization of magnetic fields around any magnetic flux or current carrying sample. It allows real time observations of domain structures and their transformations in magnetics, static and dynamic field patterns due to inhomogeneous currents in electric circuits and superconductors, and reveals distortions of the fields due to defects. In addition to qualitative pictures showing different details in the intensities of the magneto-optical images, one can obtain quantitative maps of field distributions and retrieve values of the underlying currents or magnetization variations. In this review we discuss the advantages of magneto-optics for studies of superconductors, show its place among other techniques, and report recent results in magneto-optical investigations of high temperature superconductors (HTS).

Vlasko-Vlasox, V. K.

1998-12-02T23:59:59.000Z

209

Atomic scale 0-pi transition in a high-Tc superconductor/ferromagnetic-insulator/high-T superconductor Josephson junction  

E-Print Network (OSTI)

We study the Josephson transport in a high-Tc superconductor/ferromagnetic-insulator(FI)/high-Tc superconductor numerically. We found the formation of a pi-junction in such systems. More remarkably the ground state of such junction alternates between 0- and pi-states when thickness of FI is increasing by a single atomic layer. We propose an experimental setup for observing the atomic-scale 0-pi transition. Such FI-based pi-junctions can be used to implement highly-coherent quantum bits.

Kawabata, Shiro; Asano, Yasuhiro

2011-01-01T23:59:59.000Z

210

High Temperature Superconductors: From Delivery to Applications (Presentation from 2011 Ernest Orlando Lawrence Award-winner, Dr. Amit Goyal, and including introduction by Energy Secretary, Dr. Steven Chu)  

SciTech Connect

Dr. Amit Goyal, a high temperature superconductivity (HTS) researcher at Oak Ridge National Laboratory, was named a 2011 winner of the Department of Energy's Ernest Orlando Lawrence Award honoring U.S. scientists and engineers for exceptional contributions in research and development supporting DOE and its mission. Winner of the award in the inaugural category of Energy Science and Innovation, Dr. Goyal was cited for his work in 'pioneering research and transformative contributions to the field of applied high temperature superconductivity, including fundamental materials science advances and technical innovations enabling large-scale applications of these novel materials.' Following his basic research in grain-to-grain supercurrent transport, Dr. Goyal focused his energy in transitioning this fundamental understanding into cutting-edge technologies. Under OE sponsorship, Dr. Goyal co-invented the Rolling Assisted Bi-Axially Textured Substrate technology (RABiTS) that is used as a substrate for second generation HTS wires. OE support also led to the invention of Structural Single Crystal Faceted Fiber Substrate (SSIFFS) and the 3-D Self Assembly of Nanodot Columns. These inventions and associated R&D resulted in 7 R&D 100 Awards including the 2010 R&D Magazine's Innovator of the Year Award, 3 Federal Laboratory Consortium Excellence in Technology Transfer National Awards, a DOE Energy100 Award and many others. As a world authority on HTS materials, Dr. Goyal has presented OE-sponsored results in more than 150 invited talks, co-authored more than 350 papers and is a fellow of 7 professional societies.

Goyal, Amit (Oak Ridge National Laboratory) [Oak Ridge National Laboratory

2012-05-22T23:59:59.000Z

211

High Temperature Superconductors: From Delivery to Applications (Presentation from 2011 Ernest Orlando Lawrence Award-winner, Dr. Amit Goyal, and including introduction by Energy Secretary, Dr. Steven Chu)  

ScienceCinema (OSTI)

Dr. Amit Goyal, a high temperature superconductivity (HTS) researcher at Oak Ridge National Laboratory, was named a 2011 winner of the Department of Energy's Ernest Orlando Lawrence Award honoring U.S. scientists and engineers for exceptional contributions in research and development supporting DOE and its mission. Winner of the award in the inaugural category of Energy Science and Innovation, Dr. Goyal was cited for his work in 'pioneering research and transformative contributions to the field of applied high temperature superconductivity, including fundamental materials science advances and technical innovations enabling large-scale applications of these novel materials.' Following his basic research in grain-to-grain supercurrent transport, Dr. Goyal focused his energy in transitioning this fundamental understanding into cutting-edge technologies. Under OE sponsorship, Dr. Goyal co-invented the Rolling Assisted Bi-Axially Textured Substrate technology (RABiTS) that is used as a substrate for second generation HTS wires. OE support also led to the invention of Structural Single Crystal Faceted Fiber Substrate (SSIFFS) and the 3-D Self Assembly of Nanodot Columns. These inventions and associated R&D resulted in 7 R&D 100 Awards including the 2010 R&D Magazine's Innovator of the Year Award, 3 Federal Laboratory Consortium Excellence in Technology Transfer National Awards, a DOE Energy100 Award and many others. As a world authority on HTS materials, Dr. Goyal has presented OE-sponsored results in more than 150 invited talks, co-authored more than 350 papers and is a fellow of 7 professional societies.

Goyal, Amit (Oak Ridge National Laboratory)

2012-06-28T23:59:59.000Z

212

High Temperature Superconducting Racetrack Coils for Electric Motor Applications  

Science Journals Connector (OSTI)

American Superconductor Corporation (ASC) has designed and fabricated racetrack-shaped field coils from PbBSSCO-2223 high temperature superconducting (HTS) wire for a 125 HP, four-pole motor currently being devel...

J. P. Voccio; C. B. Prum; M. J. Navarro

1997-01-01T23:59:59.000Z

213

Thermal contact conductance of metallic coated superconductor/copper interfaces at cryogenic temperatures  

E-Print Network (OSTI)

THERMAL CONTACT CONDUCTANCE OF METALLIC COATED SUPERCONDUCTOR/COPPER INTERFACES AT CRYOGENIC TEMPERATURES A Thesis by JAY MATTHEW OCHTERBECK Submitted to the 0%ce of Graduate Studies of Texas AJrM IJniversity in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1990 Major Subject: Mechanical Engineering THERMAL CONTACT CONDUCTANCE OF METALLIC COATED SUPERCONDUCTOR/COPPER INTERFACES AT CRYOGENIC TEMPERATURES A Thesis JA'r '(IATTHEW OCHTERBECK Approved...

Ochterbeck, Jay Matthew

2012-06-07T23:59:59.000Z

214

High Temperatures & Electricity Demand  

E-Print Network (OSTI)

High Temperatures & Electricity Demand An Assessment of Supply Adequacy in California Trends.......................................................................................................1 HIGH TEMPERATURES AND ELECTRICITY DEMAND.....................................................................................................................7 SECTION I: HIGH TEMPERATURES AND ELECTRICITY DEMAND ..........................9 BACKGROUND

215

Exploring Competing Orders in the High-Tc Cuprate Phase Diagram Using Angle Resolved Photoemission Spectroscopy  

E-Print Network (OSTI)

state of Cu-O high-temperature superconductors. Phys. Rev.coupling in high- temperature superconductors. Nature 412,Pseudogap in the High-Temperature Superconductor HoBa 2 Cu 4

Garcia, Daniel Robert

2010-01-01T23:59:59.000Z

216

Scanning tunneling microscopy and spectroscopy of Bi-Sr-Ca-Cu-O 2:2:1:2 high-temperature superconductors  

Science Journals Connector (OSTI)

We have used scanning tunneling microscopy and spectroscopy to investigate the surface-topographic and electronic properties of Bi-Sr-Ca-Cu-O 2:2:1:2 compounds. Even though there are two atoms (Bi and O) per lattice point, only one corrugation maximum per lattice point is observed. Polarity-dependent images show that the corrugations of the images taken at opposite polarities are in phase. We discuss possible explanations for this observation of in-phase corrugations at opposite polarities. Spectroscopic data were obtained at both high and low sample biases. Our data show that the density of surface electronic states near the Fermi level is about 34 orders of magnitude smaller than that of a typical metal. These states are only detectable when the stabilization voltage of the tunnel junction is low (<1.5 V). The conductivity near zero bias is extremely nonlinear, consistent with a nonmetallic surface layer. Vacuum resonant tunneling studies show that at these low-bias voltages the tip-to-sample distance is very small (?36 ). This small tip-to-sample distance implies that the conductivity we detect near zero bias might result from the underlying CuO layer. We find evidence of bias-field penetration into the sample, implying that the surface density of states near the Fermi level is too small to screen out the electric field.

C. K. Shih; R. M. Feenstra; G. V. Chandrashekhar

1991-04-01T23:59:59.000Z

217

Dense high temperature ceramic oxide superconductors  

DOE Patents (OSTI)

Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

Landingham, Richard L. (Livermore, CA)

1993-01-01T23:59:59.000Z

218

Surface texturing of superconductors by controlled oxygen pressure  

DOE Patents (OSTI)

A method of manufacture of a textured layer of a high temperature superconductor on a substrate. The method involves providing an untextured high temperature superconductor material having a characteristic ambient pressure peritectic melting point, heating the superconductor to a temperature below the peritectic temperature, establishing a reduced pO.sub.2 atmosphere below ambient pressure causing reduction of the peritectic melting point to a reduced temperature which causes melting from an exposed surface of the superconductor and raising pressure of the reduced pO.sub.2 atmosphere to cause solidification of the molten superconductor in a textured surface layer.

Chen, Nan (Downers Grove, IL); Goretta, Kenneth C. (Downers Grove, IL); Dorris, Stephen E. (La Grange Park, IL)

1999-01-01T23:59:59.000Z

219

Surface texturing of superconductors by controlled oxygen pressure  

DOE Patents (OSTI)

A method of manufacture of a textured layer of a high temperature superconductor on a substrate is disclosed. The method involves providing an untextured high temperature superconductor material having a characteristic ambient pressure peritectic melting point, heating the superconductor to a temperature below the peritectic temperature, establishing a reduced pO{sub 2} atmosphere below ambient pressure causing reduction of the peritectic melting point to a reduced temperature which causes melting from an exposed surface of the superconductor and raising pressure of the reduced pO{sub 2} atmosphere to cause solidification of the molten superconductor in a textured surface layer. 8 figs.

Chen, N.; Goretta, K.C.; Dorris, S.E.

1999-01-05T23:59:59.000Z

220

Anomalous microwave conductivity due to collective transport in the pseudogap state of cuprate superconductors  

E-Print Network (OSTI)

that there is a common phenomenol- ogy for all high-temperature superconductors: the existence of a partial gap

Sridhar, Srinivas

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Ambient-pressure organic superconductor  

DOE Patents (OSTI)

A new class of organic superconductors having the formula (ET).sub.2 MX.sub.2 wherein ET represents bis(ethylenedithio)-tetrathiafulvalene, M is a metal such as Au, Ag, In, Tl, Rb, Pd and the like and X is a halide. The superconductor (ET).sub.2 AuI.sub.2 exhibits a transition temperature of 5 K which is high for organic superconductors.

Williams, Jack M. (Downers Grove, IL); Wang, Hsien-Hau (Willowbrook, IL); Beno, Mark A. (Woodridge, IL)

1986-01-01T23:59:59.000Z

222

Superconductor stability 90: A review  

SciTech Connect

This paper reviews some recent developments in the field of stability of superconductors. The main topics dealt with are hydrodynamic phenomena in cable-in-conduit superconductors, namely, multiple stability, quench pressure, thermal expulsion, and thermal hydraulic quenchback, traveling normal zones in large, composite conductors, such as those intended for SMES, and the stability of vapor-cooled leads made of high-temperature superconductors. 31 refs., 5 figs.

Dresner, L.

1990-01-01T23:59:59.000Z

223

The Magnetic Excitation Spectrum and Thermodynamics of High-Tc Superconductors  

Science Journals Connector (OSTI)

...1126/science.284.5418.1344 Pengcheng Dai H. A. Mook S. M. Hayden G. Aeppli...Thermodynamics of High-Tc Superconductors Pengcheng Dai, 1* H. A. Mook, 1 S...Thermodynamics of High-Tc Superconductors Pengcheng Dai, 1* H. A. Mook, 1 S. M. Hayden...

Pengcheng Dai; H. A. Mook; S. M. Hayden; G. Aeppli; T. G. Perring; R. D. Hunt; F. Do?an

1999-05-21T23:59:59.000Z

224

Evolution of low-energy spin dynamics in the electron-doped high-transition-temperature superconductor Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}}  

SciTech Connect

We use inelastic neutron scattering to explore the evolution of the low energy spin dynamics in the electron-doped cuprate Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} (PLCCO) as the system is tuned from its nonsuperconducting, as-grown antiferromagnetic (AF) state into an optimally doped superconductor (T{sub c}{approx_equal}24 K) without static AF order. The low-temperature, low-energy response of the spin excitations in underdoped samples is coupled to the presence of the AF phase, whereas the low-energy magnetic response for samples near optimal T{sub c} exhibits spin fluctuations surprisingly insensitive to the sample temperature. This evolution of the low-energy excitations is consistent with the influence of a quantum critical point in the phase diagram of PLCCO associated with the suppression of the static AF order. We carried out scaling analysis of the data and discuss the influence of quantum critical dynamics in the observed excitation spectrum.

Wilson, Stephen D.; Li Shiliang [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Dai Pengcheng [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Bao, Wei [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Chung, Jae-Ho; Kang, H. J. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562 (United States); Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115 (United States); Lee, Seung-Hun [Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714 (United States); Komiya, Seiki; Ando, Yoichi [Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511 (Japan); Si, Qimiao [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

2006-10-01T23:59:59.000Z

225

High field superconductor development and understanding project, Final Report  

SciTech Connect

Over 25 years the Applied Superconductivity Center at the University of Wisconsin-Madison provided a vital technical resource to the High Energy Physics community covering development in superconducting strand for HEP accelerator magnet development. In particular the work of the group has been to develop the next generation of high field superconductors for high field application. Grad students Mike Naus, Chad Fischer, Arno Godeke and Matt Jewell improved our understanding of the microstructure and microchemistry of Nb3Sn and their impact on the physical and mechanical properties. The success of this work has led to the continued funding of this work at the ASC after it moved to the NHMFL and also to direct funding from BNL for some aspects of Nb3Sn cable evaluation.

Larbalestier, David C.; Lee, Peter J.

2009-07-15T23:59:59.000Z

226

Engineered flux-pinning centers in BSCCO TBCCO and YBCO superconductors  

DOE Patents (OSTI)

A method of preparing a high temperature superconductor is disclosed. A method of preparing a superconductor includes providing a powdered high temperature superconductor and a nanophase material. These components are combined to form a solid compacted mass with the material disposed in the polycrystalline high temperature superconductor. This combined mixture is rapidly heated, forming a dispersion of nanophase size particles without a eutectic reaction. These nanophase particles can have a flat plate or columnar type morphology. 4 figs.

Goretta, K.C.; Lanagan, M.T.; Miller, D.J.; Sengupta, S.; Parker, J.C.; Hu, J.; Balachandran, U.; Siegel, R.W.; Shi, D.

1999-07-27T23:59:59.000Z

227

Engineered flux-pinning centers in BSCCO TBCCO and YBCO superconductors  

DOE Patents (OSTI)

A method of preparing a high temperature superconductor. A method of preparing a superconductor includes providing a powdered high temperature superconductor and a nanophase material. These components are combined to form a solid compacted mass with the material disposed in the polycrystalline high temperature superconductor. This combined mixture is rapidly heated, forming a dispersion of nanophase size particles without a eutectic reaction. These nanophase particles can have a flat plate or columnar type morphology.

Goretta, Kenneth C. (Downers Grove, IL); Lanagan, Michael T. (Woodridge, IL); Miller, Dean J. (Darien, IL); Sengupta, Suvankar (Upper Arlington, OH); Parker, John C. (Naperville, IL); Hu, Jieguang (Woodridge, IL); Balachandran, Uthamalingam (Hinsdale, IL); Siegel, Richard W. (Hinsdale, IL); Shi, Donglu (Oak Park, IL)

1999-01-01T23:59:59.000Z

228

Processes yielding high superconducting temperatures  

SciTech Connect

It is pointed out that any microscopic description of the new high-T/sub c/ superconductors should take into account a number of important points concerning strong couplings, whatever their nature: absence of the MacMillan limit, absence of a Migdal theorem, and importance of the Brovman-Kagan type of vertices with different singularities depending on the dimensionality. As a consequence, the applicability of standard techniques such as the Eliashberg theory in particular, may be questioned in high-T/sub c/ superconductors.

Beal-Monod, M.T.

1987-12-01T23:59:59.000Z

229

Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements  

SciTech Connect

Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

Trela, W.J.; Kwei, G.H.; Lynn, J.E. [Los Alamos National Lab., NM (United States); Meggers, K. [Univ. of Kiel (Germany)

1994-12-01T23:59:59.000Z

230

Processing and fabrication of high-{Tc} superconductors for electric power applications  

SciTech Connect

Recent developments in the powder-in-tube fabrication of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes include identification of high current transport regions of the superconductor core, optimization of conductor design and processing to take advantage of these high current regions, optimization of superconductor powders and heat treatments, and incorporation of flux pinning defects into the superconductor grains. These developments are briefly discussed and their implications are assessed.

Balachandran, U.; Iyer, A.N.; Goretta, K.C. [Argonne National Lab., IL (United States). Energy Technology Div.; Haldar, P. [Intermagnetics General Corp., Latham, NY (United States)

1997-09-01T23:59:59.000Z

231

Superconductive fluctuations in the density of states and tunneling resistance in high-Tc superconductors  

Science Journals Connector (OSTI)

The effect of superconductive fluctuations on the density of states and tunneling resistance is revisited in the case of dirty superconductors and derived for clean samples with and without pair-breaking sources. For clean superconductors new features appear in the density of states. In particular, with respect to the commonly known dirty case, the fluctuation effects manifest themselves on a new scale of energy with a different power-law behavior as function of T-Tc. The relevance of these results for high-Tc superconductors is analyzed.

C. Di Castro, R. Raimondi, C. Castellani, and A. A. Varlamov

1990-12-01T23:59:59.000Z

232

Hall effect and resistivity in high-Tc superconductors: The conserving approximation  

Science Journals Connector (OSTI)

The Hall coefficient RH in high-Tc cuprates in the normal state shows the striking non-Fermi-liquid behavior: RH follows a Curie-Weiss type temperature dependence and |RH|?1/|ne| at low temperatures in the underdoped compounds. Moreover, RH is positive for hole-doped compounds and negative for electron-doped ones, although each of them has a similar holelike Fermi surface. In this paper, we give the explanation of this long-standing problem from the standpoint of the nearly antiferromagnetic (AF) Fermi liquid. We consider seriously the vertex corrections for the current which are indispensable to satisfy the conservation laws, which are violated within the conventional Boltzmann transport approximation. The obtained total current Jk takes an enhanced value and is no longer perpendicular to the Fermi surface due to the strong AF fluctuations. By virtue of this mechanism, the anomalous behaviors of RH in high-Tc cuprates are naturally explained. Both the temperature and the (electron, hole) doping dependences of RH in high-Tc cuprates are reproduced well by numerical calculations based on the fluctuation-exchange approximation, applied to the single-band Hubbard model with a holelike Fermi surface. We also discuss the singular temperature dependence of RH in other nearly AF metals, e.g., V2O3, ?-BEDT-TTF organic superconductors, and heavy fermion systems close to the AF phase boundary.

Hiroshi Kontani; Kazuki Kanki; Kazuo Ueda

1999-06-01T23:59:59.000Z

233

High temperature pressure gauge  

DOE Patents (OSTI)

A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

Echtler, J. Paul (Pittsburgh, PA); Scandrol, Roy O. (Library, PA)

1981-01-01T23:59:59.000Z

234

High temperature probe  

DOE Patents (OSTI)

A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

Swan, Raymond A. (Fremont, CA)

1994-01-01T23:59:59.000Z

235

The influence of the Al stabilizer layer thickness on the normal zone propagation velocity in high current superconductors  

E-Print Network (OSTI)

The stability of high-current superconductors is challenging in the design of superconducting magnets. When the stability requirements are fulfilled, the protection against a quench must still be considered. A main factor in the design of quench protection systems is the resistance growth rate in the magnet following a quench. The usual method for determining the resistance growth in impregnated coils is to calculate the longitudinal velocity with which the normal zone propagates in the conductor along the coil windings. Here, we present a 2D numerical model for predicting the normal zone propagation velocity in Al stabilized Rutherford NbTi cables with large cross section. By solving two coupled differential equations under adiabatic conditions, the model takes into account the thermal diffusion and the current redistribution process following a quench. Both the temperature and magnetic field dependencies of the superconductor and the metal cladding materials properties are included. Unlike common normal zon...

Shilon, I; Langeslag, S A E; Martins, L P; Kate, H H J ten

2014-01-01T23:59:59.000Z

236

Chemistry at High Temperatures  

Science Journals Connector (OSTI)

...347 the condensed phase. Both cases are...show the opposite behavior. These predictions...vapors. Condensed phase B203 B + B203 02...complex silicates and hydrates in high-temperature...characterized by phase diagrams (derived...doubt that thou-sands of new chemical materials...

John L. Margrave

1962-02-02T23:59:59.000Z

237

High performance magnetic bearing systems using high temperature superconductors  

DOE Patents (OSTI)

Disclosed are a magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly. 7 figs.

Abboud, R.G.

1998-05-05T23:59:59.000Z

238

Design of High Field Solenoids made of High Temperature Superconductors.  

E-Print Network (OSTI)

??This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed (more)

BARTALESI, ANTONIO

2009-01-01T23:59:59.000Z

239

High performance magnetic bearing systems using high temperature superconductors  

DOE Patents (OSTI)

A magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly.

Abboud, Robert G. (Barrington Hills, IL)

1998-01-01T23:59:59.000Z

240

High temperature thermometric phosphors  

DOE Patents (OSTI)

A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.y) wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN); Gillies, George T. (Earlysville, VA)

1999-03-23T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

High Temperature Membrane Working Group  

Energy.gov (U.S. Department of Energy (DOE))

The High Temperature Membrane Working Group consists of government, industry, and university researchers interested in developing high temperature membranes for fuel cells.

242

Anomalies in Ultra-High-Field Magnetic Superconductors (Eu1-xSnx)Mo6S8  

Science Journals Connector (OSTI)

Resistive behavior of three series of Chevrel phase, (Eu1-xSnx)Mo6S7, (Eu1-xSnx)Mo6S6.75 and (Eu1-xSnx)0.9Mo6S6.75, is studied in magnetic fields up to 90 kOe at temperatures down to 50 mK. Compounds with x>0.4 are usual ultra-high-field superconductors, while (Eu0.9Sn0.1)0.9Mo6S6.75 is a simple magnetic superconductor. Resistive behavior of the compounds between the above mentioned two sides is complicated, varying with the composition. For example, in (Eu0.8Sn0.2)Mo6S7 the resistance at high fields keeps roughly constant and the temperature dependence of Hc2 defined as a half of the resistance in the normal state is quite different with that defined at the appearance of the resistance. In (Eu0.85Sn0.15)Mo6S7 the superconductivity (=zero resistance) seems to reappear at high fields and at low temperatures.

Masahiro Isino; Norio Kobayashi; Yoshio Muto

1980-01-01T23:59:59.000Z

243

Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing  

DOE Patents (OSTI)

Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

Hull, John R. (Downers Grove, IL)

2000-01-01T23:59:59.000Z

244

A simple figure of merit for high temperature superconducting switches  

SciTech Connect

The discovery of the new high temperature superconductors has revived interest in many special applications, including superconducting switches. For comparison of switch types, a simple figure of merit based in switch performance is proposed, derived for superconducting switches, and then calculated for thyristors and vacuum switches. The figure of merit is then used to show what critical current density would be needed for superconducting switches to compete with more conventional switches. 46 refs., 1 fig.

Honig, E.M.

1989-01-01T23:59:59.000Z

245

High Temperature Membrane Working Group  

Energy.gov (U.S. Department of Energy (DOE))

This presentation provides an overview of the High Temperature Membrane Working Group Meeting in May 2007.

246

High Temperature | Open Energy Information  

Open Energy Info (EERE)

Temperature Temperature Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Sanyal Temperature Classification: High Temperature Dictionary.png High Temperature: No definition has been provided for this term. Add a Definition Sanyal Temp Classification This temperature scheme was developed by Sanyal in 2005 at the request of DOE and GEA, as reported in Classification of Geothermal Systems: A Possible Scheme. Extremely Low Temperature Very Low Temperature Low Temperature Moderate Temperature High Temperature Ultra High Temperature Steam Field Reservoir fluid between 230°C and 300°C is considered by Sanyal to be "high temperature." "Above a temperature level of 230°C, the reservoir would be expected to become two-phase at some point during exploitation. The next higher

247

Acoustic microscopy for characterization of high?temperature superconducting tape  

Science Journals Connector (OSTI)

Although material scientists constantly discover superconducting compounds with higher critical temperatures (T c s) manufacturing of the high?temperature superconductors(HTS) remains a problem and long lengths (>1 mile) have yet to be produced. In an effort to produce long length superconductors manufacturing steps for HTS tape production have been critically looked at to find their effects in producing tape with the desired characteristics. In support of determining superconducting tapecharacteristics acoustic microscopy offers the potential for internal microstructural material characterization. This research will ultimately support in?process monitoring of HTSmanufacturing as part of an advanced sensing system to determine the presence of defects and/or the effects of process variables on the HTS tape. This presentation will overview scanning acoustic microscopy and present images of HTS tape at several frequencies ranging from 50 to 500 MHz. The results clearly demonstrate the feasibility of determining the Ag/ceramic interface location and the general integrity of the constituents.

Chiaki Miyasaka; Chris Cobucci; Bernhard Tittmann

1997-01-01T23:59:59.000Z

248

High temperature detonator  

DOE Patents (OSTI)

A detonator assembly is provided which is usable at high temperatures about 300.degree. C. A detonator body is provided with an internal volume defining an anvil surface. A first acceptor explosive is disposed on the anvil surface. A donor assembly having an ignition element, an explosive material, and a flying plate, are placed in the body effective to accelerate the flying plate to impact the first acceptor explosive on the anvil for detonating the first acceptor explosive. A second acceptor explosive is eccentrically located in detonation relationship with the first acceptor explosive to thereafter effect detonation of a main charge.

Johnson, James O. (Los Alamos, NM); Dinegar, Robert H. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

249

Electron Correlation in Iron-Based Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Correlation in Iron-Based Superconductors Print Electron Correlation in Iron-Based Superconductors Print In 2008, the discovery of iron-based superconductors stimulated a worldwide burst of activity, leading to about two preprints per day ever since. With a maximum superconducting transition temperature (so far) of 55 K, it is natural to wonder if studying the new materials will help uncover one of the deepest mysteries in modern physics-the mechanism of superconductivity in the copper-based "high-temperature superconductors." One clue lies in whether the electrons in the new superconductors are as highly correlated as they are in the high-temperature superconductors. A truly international North American/European/Asian collaboration working at the ALS has now reported results from a combination of x-ray absorption spectroscopy, resonant inelastic x-ray scattering, and systematic theoretical simulations of iron-based superconductors. The team was able to settle the correlations debate by showing that electrons in the iron-based families that were studied favor itinerant (delocalized) states with only moderate correlations.

250

Electron Correlation in Iron-Based Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Correlation in Iron-Based Superconductors Print Electron Correlation in Iron-Based Superconductors Print In 2008, the discovery of iron-based superconductors stimulated a worldwide burst of activity, leading to about two preprints per day ever since. With a maximum superconducting transition temperature (so far) of 55 K, it is natural to wonder if studying the new materials will help uncover one of the deepest mysteries in modern physics-the mechanism of superconductivity in the copper-based "high-temperature superconductors." One clue lies in whether the electrons in the new superconductors are as highly correlated as they are in the high-temperature superconductors. A truly international North American/European/Asian collaboration working at the ALS has now reported results from a combination of x-ray absorption spectroscopy, resonant inelastic x-ray scattering, and systematic theoretical simulations of iron-based superconductors. The team was able to settle the correlations debate by showing that electrons in the iron-based families that were studied favor itinerant (delocalized) states with only moderate correlations.

251

Electron Correlation in Iron-Based Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Correlation in Iron-Based Superconductors Print Electron Correlation in Iron-Based Superconductors Print In 2008, the discovery of iron-based superconductors stimulated a worldwide burst of activity, leading to about two preprints per day ever since. With a maximum superconducting transition temperature (so far) of 55 K, it is natural to wonder if studying the new materials will help uncover one of the deepest mysteries in modern physics-the mechanism of superconductivity in the copper-based "high-temperature superconductors." One clue lies in whether the electrons in the new superconductors are as highly correlated as they are in the high-temperature superconductors. A truly international North American/European/Asian collaboration working at the ALS has now reported results from a combination of x-ray absorption spectroscopy, resonant inelastic x-ray scattering, and systematic theoretical simulations of iron-based superconductors. The team was able to settle the correlations debate by showing that electrons in the iron-based families that were studied favor itinerant (delocalized) states with only moderate correlations.

252

Electron Correlation in Iron-Based Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Correlation in Iron-Based Superconductors Print Electron Correlation in Iron-Based Superconductors Print In 2008, the discovery of iron-based superconductors stimulated a worldwide burst of activity, leading to about two preprints per day ever since. With a maximum superconducting transition temperature (so far) of 55 K, it is natural to wonder if studying the new materials will help uncover one of the deepest mysteries in modern physics-the mechanism of superconductivity in the copper-based "high-temperature superconductors." One clue lies in whether the electrons in the new superconductors are as highly correlated as they are in the high-temperature superconductors. A truly international North American/European/Asian collaboration working at the ALS has now reported results from a combination of x-ray absorption spectroscopy, resonant inelastic x-ray scattering, and systematic theoretical simulations of iron-based superconductors. The team was able to settle the correlations debate by showing that electrons in the iron-based families that were studied favor itinerant (delocalized) states with only moderate correlations.

253

Electron Correlation in Iron-Based Superconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Correlation in Iron-Based Superconductors Print Electron Correlation in Iron-Based Superconductors Print In 2008, the discovery of iron-based superconductors stimulated a worldwide burst of activity, leading to about two preprints per day ever since. With a maximum superconducting transition temperature (so far) of 55 K, it is natural to wonder if studying the new materials will help uncover one of the deepest mysteries in modern physics-the mechanism of superconductivity in the copper-based "high-temperature superconductors." One clue lies in whether the electrons in the new superconductors are as highly correlated as they are in the high-temperature superconductors. A truly international North American/European/Asian collaboration working at the ALS has now reported results from a combination of x-ray absorption spectroscopy, resonant inelastic x-ray scattering, and systematic theoretical simulations of iron-based superconductors. The team was able to settle the correlations debate by showing that electrons in the iron-based families that were studied favor itinerant (delocalized) states with only moderate correlations.

254

Low temperature London penetration depth and superfluid density in Fe-based superconductors  

SciTech Connect

The superconducting gap symmetry of the Fe-based superconductors was studied by measurements and analysis of London penetration depth and super uid density. Tunnel diode resonator technique for these measurements was implemented in a dilution refrigerator allowing for the temperatures down to 50 mK. For the analysis of the super uid density, we used both experimental studies of Al-coated samples and original thermodynamic approach based on Rutgers relation. In three systems studied, we found that the superconducting gap at the optimal doping is best described in multi-gap full gap scenario. By performing experiments on samples with arti#12;cially introduced disorder with heavy ion irradiation, we show that evolution of the superconducting transition temperature and of the super uid density are consistent with full-gap sign changing s#6; superconducting state. The superconducting gap develops strong modulation both in the under-doped and the over-doped regimes. In the terminal hole-doped KFe{sub 2}As{sub 2}, both temperature dependence of the super uid density and its evolution with increase of the scattering rate are consistent with symmetry imposed vertical line nodes in the superconducting gap. By comparative studies of hole-doped (Ba,K)Fe{sub 2}As{sub 2} and electron-doped Ca10-3-8, we show that the superconducting gap modulation in the under-doped regime is intrinsic and is not induced by the coexisting static magnetic order.

Kim, Hyunsoo [Ames Laboratory] [Ames Laboratory

2013-05-15T23:59:59.000Z

255

High-Temperature Water Splitting  

Energy.gov (U.S. Department of Energy (DOE))

High-temperature water splitting (a "thermochemical" process) is a long-term technology in the early stages of development.

256

Hall effect in the marginal Fermi liquid regime of high-Tc superconductors  

Science Journals Connector (OSTI)

The detailed derivation of a theory for transport in quasi-two-dimensional metals, with small-angle elastic scattering and angle-independent inelastic scattering is presented. The transport equation is solved for a model Fermi surface representing a typical cuprate superconductor. Using the small-angle elastic and the inelastic scattering rates deduced from angle-resolved photoemission experiments, good quantitative agreement with the observed anomalous temperature dependence of the Hall angle in optimally doped cuprates is obtained, while the resistivity remains linear in temperature. The theory is also extended to the frequency-dependent complex Hall angle.

Elihu Abrahams and C. M. Varma

2003-09-04T23:59:59.000Z

257

Superconducting trapped-field magnets: Temperature and field distributions during pulsed-field activation  

E-Print Network (OSTI)

progress in fabrication of large-sized high- temperature superconductors with high critical current den We calculate the temperature and magnetic field distributions in a bulk superconductor during leads to a strong temperature rise in superconductor during the activation pro- cess. There have already

Johansen, Tom Henning

258

Rational design of high-current cable-in-conduit superconductors  

SciTech Connect

Cable-in-conduit superconductors are composed of a cable of many fine composite strands encased in a strong, protective jacket, with helium coolant filling the interstices of the cable. Because of the high degree of subdivision of the composite and its consequent large cooled surface, such conductors are capable of stable operation at quite high current densities. The designer of such conductors is frequently given the field at the conductor and the overall current density and asked to specify the remaining variables of the conductor (e.g., the strand diameter, the hydraulic path length, the void fraction of the cable, and the Cu/SC ratio). This paper outlines a rational procedure for determining the most problematic variables, the two composition variables that determine the proportions of copper, superconductor, and helium in the cable space. All other variables of the conductor are assumed known. 14 refs., 8 figs.

Dresner, L.

1989-01-01T23:59:59.000Z

259

Quench energies of composite superconductors  

E-Print Network (OSTI)

Quench energies of composite superconductors A.VI. Gurevich, R.G. Mints and A.A. Pukhov The Institute for High Temperatures, Moscow, 12741 2, USSR Received 3 June 1988 The quench energy of composite for the cases of one-, two- and three-dimensional heat propagation. Quench energy is shown to be both higher

Mints, Roman G.

260

Density Functional Theory for Superconductors  

E-Print Network (OSTI)

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

High-temperature Pump Monitoring - High-temperature ESP Monitoring...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Report Detecting Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report...

262

Anomalous Fermi-Surface Dependent Pairing in a Self-Doped High-Tc Superconductor  

SciTech Connect

We report the discovery of a self-doped multi-layer high T{sub c} superconductor Ba{sub 2}Ca{sub 3}Cu{sub 4}O{sub 8}F{sub 2} (F0234) which contains distinctly different superconducting gap magnitudes along its two Fermi surface(FS) sheets. While formal valence counting would imply this material to be an undoped insulator, it is a self-doped superconductor with a T{sub c} of 60K, possessing simultaneously both electron- and hole-doped FS sheets. Intriguingly, the FS sheet characterized by the much larger gap is the electron-doped one, which has a shape disfavoring two electronic features considered to be important for the pairing mechanism: the van Hove singularity and the antiferromagnetic ({pi}/a, {pi}/a) scattering.

Chen, Y.

2010-05-03T23:59:59.000Z

263

Anomalous Fermi-Surface Dependent Pairing in a Self-Doped High-T(c) Superconductor  

SciTech Connect

We report the discovery of a self-doped multilayer high T{sub c} superconductor Ba{sub 2}Ca{sub 3}Cu{sub 4}O{sub 8}F{sub 2} (F0234) which contains distinctly different superconducting gap magnitudes along its two Fermi-surface sheets. While formal valence counting would imply this material to be an undoped insulator, it is a self-doped superconductor with a T{sub c} of 60 K, possessing simultaneously both electron- and hole-doped Fermi-surface sheets. Intriguingly, the Fermi-surface sheet characterized by the much larger gap is the electron-doped one, which has a shape disfavoring two electronic features considered to be important for the pairing mechanism: the van Hove singularity and the antiferromagnetic ({pi}/{alpha}, {pi}/{alpha}) scattering.

Chen, Yulin; Iyo, Akira; Yang, Wanli; Zhou, Xingjiang; Lu, Donghui; Eisaki, Hiroshi; Devereaux, Thomas P.; Hussain, Zahid; Shen, Z.-X.; /Stanford U., Phys. Dept. /SLAC,

2007-02-12T23:59:59.000Z

264

Recent advances in fabrication of high-T{sub c} superconductors for electric power applications.  

SciTech Connect

The U.S. Department of Energy (DOE) supports an applied superconductivity program entitled ''Superconductivity Program for Electric Power Systems.'' Activities within this program contribute to development of the high-temperature superconductor (HTS) technology needed for industry to proceed with the commercial development of electric power applications such as motors, generators, transformers, transmission cables, and current limiters. Research is conducted in three categories: wire development, systems technology development, and Superconductivity Partnership Initiative (SPI). Wire development activities are devoted to improving the critical current density (J{sub c}) of short-length HTS wires, whereas systems technology development focuses on fabrication of long-length wires, coils, and on magnets. The SPI activities are aimed at development of prototype products. Significant progress has been made in the development of (HTSs) for various applications: some applications have already made significant strides in the marketplace, while others are still in the developmental stages. For successful electric power applications, it is very important that the HTS be fabricated into long-length conductors that exhibit desired superconducting and mechanical properties. Several parameters of the PIT technique must be carefully controlled to obtain the desired properties. Long lengths of Bi-2223 tapes with respectable superconducting properties have been fabricated by a carefully designed thermomechanical treatment process. A 1-MVA capacity fault current limiter, a 286-hp motor, and 630-kVA transformers, and a 50-m-long conductor, all using HTSs, have already been demonstrated. While the use of HTS devices in the electric utility area has clear advantages, impediments to successful commercialization remain. Issues such as AC losses, conductor cost, and reliable superconducting joints must be addressed. The cost of HTS conductors are still quite high, and significant R and D effort must be focused on this issue. The general acceptance of HTS power equipment will ultimately be based on system performance, reliability and maintenance, efficiency, and installed cost relative to those of conventional technologies.

Balachandran, U.

1998-03-25T23:59:59.000Z

265

High Temperature Structural Foam  

Science Journals Connector (OSTI)

The Aerospace Industry is experiencing growing demand for high performance polymer foam. The X-33 program needs structural foam insulation capable of retaining its strength over a wide range of environmental conditions. The High Speed Research Program ...

Weiser Erik S.; Baillif Faye F.; Grimsley Brian W.; Marchello Joseph M.

1998-05-01T23:59:59.000Z

266

Quench development in a high temperature superconducting tape  

SciTech Connect

Normal zone propagation experiments have been performed on a long length of Bi-2223/Ag high temperature superconducting (HTS) tape. Tests were conducted with liquid nitrogen and gaseous helium cooling in temperatures from 5 to 77 K. No sustained expansion of a {open_quotes}normal{close_quotes} zone was observed with a short resistive heater. Non-uniform critical currents were, however, observed over the length of the conductor. When the conductor was charged and held at a current above the critical currents of weaker sections, a quench was being developed without distinctive {open_quotes}normal{close_quotes} zone propagation. Because of the high temperature margin and broad resistive transition of the superconductor, and the good thermal conductivity of the Ag-matrix, the quench process was very slow. and no large temperature gradient along the conductor was observed.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corporation, Westborough, MA (United States)

1996-12-31T23:59:59.000Z

267

Quench development in a high temperature superconducting tape  

SciTech Connect

Normal zone propagation experiments have been per-formed on a long length of Bi2223/Ag high temperature superconducting (HTS) tape. Tests were performed in liquid nitrogen and with gaseous helium cooling in temperatures ranging from 4.2 K to 77 K. No sustained expansion of a ``normal`` zone was observed with a short resistive heater. Non-uniform critical currents were, however, observed over the length of the conductor. When the conductor was charged and held at a current above the critical currents of weaker sections, a quench was being developed without distinctive ``normal`` zone propagation. Because of the high temperature margin and broad resistive transition of the superconductor, and the good thermal conductivity of the Ag-matrix, the quench process was very slow, and no large temperature gradient along the conductor was observed in the test duration of a few minutes.

Lue, J.W.; Lubell, M.S. [Argonne National Lab., IL (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corp., Westborough, MA (United States)

1995-12-01T23:59:59.000Z

268

High-temperature stability, structure and thermoelectric properties of CaMn1xNbxO3 phases  

E-Print Network (OSTI)

technologies such as solid oxide fuel cells, thermoelectric (TE) modules and high-temperature superconductorsHigh-temperature stability, structure and thermoelectric properties of CaMn1?xNbxO3 phases Laura diffraction and electron diffraction data. Thermogravi- metric heating/cooling studies showed a reversible

269

High Temperature Processing Symposium 2014  

E-Print Network (OSTI)

} High temperature recycling operations } Materials sustainability } New furnace technology (including solar) We look forward to seeing you in February 2014. Dr M Akbar Rhamdhani (Chairman HTPS 2014) Prof

Liley, David

270

Powder synthesis and consolidation of thallium based high temperature superconductors  

SciTech Connect

Objective is to provide research samples of the Tl-based powders prepared by Rockwell's spray calciner. Target compositions were set at 1.1 Tl, 1 Ba, 1 Ca, 1.5 Cu and 1.1 Tl, 1.12 Ba, 1 Ca, 1.88 Cu. Three calciner runs were made. The Nomex bags were replaced with Gore-Tex bags. The system was operated continuously for 24 h, producing 1.7 kg HTSC powder. Problems with CO[sub 2], Tl volatility during sintering, etc., are discussed.

Gay, R.L. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.)

1990-06-23T23:59:59.000Z

271

Josephson junctions in high-T/sub c/ superconductors  

DOE Patents (OSTI)

The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

Falco, C.M.; Lee, T.W.

1981-01-14T23:59:59.000Z

272

Design and current-limiting simulation of magnetic-shield type superconducting fault current limiter with high-Tc superconductors  

SciTech Connect

The continuous development of electric power utilities has led to the increase in the problems concerning fault currents. The use of fault current limiters, which suppress fault currents below a prescribed level, has been examined in many places. The authors have studied a superconducting fault current limiter that is based on the magnetic shielding effect of superconductors. In this paper, the authors derive a requirement for leading to a flux-jumping inside a ceramic superconductor at liquid nitrogen temperature. Next, two kinds of magnetic-shield type superconducting fault current limiters are designed, and their current-limiting simulations are tried using a computer.

Kajikawa, K.; Kaiho, K.; Tamada, N. [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)] [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Onishi, T. [Hokkaido Univ., Sapporo (Japan)] [Hokkaido Univ., Sapporo (Japan)

1996-07-01T23:59:59.000Z

273

Philosophy 26 High Temperature Superconductivity  

E-Print Network (OSTI)

is the ratio of voltage to current. The resistance of a material tells us how a low resistance, and they are therefore good conductors; other materials, likePhilosophy 26 High Temperature Superconductivity By Ohm's Law, resistance

Callender, Craig

274

Experiment Hazard Class 3 - High Temperatures  

NLE Websites -- All DOE Office Websites (Extended Search)

Operation * APS Base Low Temperatures * Cryogenic Systems High Temperatures * Electric Furnace * Optical Furnace * Other High Temperature Lasers * Laser, Class 2 * Laser,...

275

Improved ambient-pressure organic superconductor. [Bis(ethylenedithio)TTF-MX/sub 2/  

DOE Patents (OSTI)

Disclosed is a new class of organic superconductors having the formula (ET)/sub 2/MX/sub 2/ wherein ET represents bis(ethylenedithio)-tetrathiafulvalene, M is a metal such as Au, Ag, In, Tl, Rb, Pd and the like and X is a halide. The superconductor (ET)/sub 2/AuI/sub 2/ exhibits a transition temperature of 5/sup 0/K which is high for organic superconductors.

Williams, J.M.; Wang, Hsien-Hau; Beno, M.A.

1985-05-29T23:59:59.000Z

276

Temperature controlled high voltage regulator  

DOE Patents (OSTI)

A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

Chiaro, Jr., Peter J. (Clinton, TN); Schulze, Gerald K. (Knoxville, TN)

2004-04-20T23:59:59.000Z

277

High temperature lightweight foamed cements  

DOE Patents (OSTI)

Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

Sugama, Toshifumi.

1989-10-03T23:59:59.000Z

278

Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system  

SciTech Connect

This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

1989-04-01T23:59:59.000Z

279

High Temperature Optical Gas Sensing  

NLE Websites -- All DOE Office Websites (Extended Search)

Optical Gas Sensing Optical Gas Sensing Opportunity Research is active on optical sensors integrated with advanced sensing materials for high temperature embedded gas sensing applications. Patent applications have been filed for two inventions in this area and several other methods are currently under development. These technologies are available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory (NETL). Organizations or individuals with capabilities in optical sensor packaging for harsh environment and high temperature applications are encouraged to contact NETL to explore potential collaborative opportunities. Overview Contact NETL Technology Transfer Group techtransfer@netl.doe.gov

280

Potential methods for the fabrication of high-T/sub c/ superconductors for wires and cables  

SciTech Connect

In this paper studies on practical properties, such as upper critical field and critical-current density of high-T/sub c/ oxide superconductors of Y-Ba-Cu-O, Bi-Sr-Ca-Cu-O, and Tl-Ba-Ca-Cu-O systems, are reviewed. Recent developments of fabrication processes that have good potentiality for producing wire or tape conductors of high-T/sub c/ oxide are then discussed. Some details are presented for the powder method (which is classified into use of an organic binder and a metal sheath) and for other fabrication processes using diffusion, solidification, and deposition techniques. For the Ag-sheathed oxide tapes, J/sub c/ values exceeding 10 000 A/cm/sup 2/ at 77 {Kappa} and 0 T have been reported for both Bi and Tl oxide materials. Further developments in fabrication processes that can overcome various problems limiting the transport J/sub c/ are required.

Tachikawa, K. (Tokai Univ., Hiratsuka, Kanagawa (Japan). Dept. of Physics); Togano, K. (National Research Inst. for Metals, Tsukuba, Ibaraki (Japan). Tsukuba Lab.)

1989-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Numerical procedure for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors  

E-Print Network (OSTI)

Numerical procedure is developed for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors, and is applied to three sets of higher resolution data provided to us by J. C. Seamus Davis and E. W. Hudson. Each image...

Wang, Q.; Hu, Chia-Ren.

2004-01-01T23:59:59.000Z

282

High-Tc superconductivity originated from strong spin-charge correlation: indication from linear temperature dependence of resistivity  

E-Print Network (OSTI)

Both the highest- and the linear temperature dependence of the resistivity in wide temperature range appear at the optimally doped regions of Cu-based superconductors1,2,3,4,5, and the highest- of Fe-based superconductors6,7 are also associated with the linear temperature dependence of the resistivity in normal states near superconducting states. This means that the high temperature superconductivity and the linear temperature dependence of the resistivity should be dominated by the same mechanism. This letter on theoretic calculation clearly shows that strong spin-charge correlation dominated resistivity behaves the linear temperature dependence, thus high-temperature superconductivity should be induced by strong spin-charge correlation.

Tian De Cao

2007-06-01T23:59:59.000Z

283

High temperature turbine engine structure  

DOE Patents (OSTI)

A high temperature turbine engine includes a rotor portion having axially stacked adjacent ceramic rotor parts. A ceramic/ceramic joint structure transmits torque between the rotor parts while maintaining coaxial alignment and axially spaced mutually parallel relation thereof despite thermal and centrifugal cycling.

Boyd, Gary L. (Tempe, AZ)

1991-01-01T23:59:59.000Z

284

Superconductors and Complex Transition Metal Oxides for Tunable THz Plasmonic Metamaterials  

SciTech Connect

The outline of this presentation are: (1) Motivation - Non-tunability of metal metamaterials; (2) Superconductors for temperature tunable metamaterials; (3) Ultrafast optical switching in superconductor metamaterials; (4) Controlling the conductivity with infrared pump beam; (5) Complex metal oxides as active substrates - Strontium Titanate; and (6) Conclusion. Conclusions are: (1) High Tc superconductors good for tunable and ultrafast metamaterials; (2) Large frequency and amplitude tunability in ultrathin superconductor films; (3) Such tunable properties cannot be accessed using metals; (4) Complex metal oxides can be used as active substrates - large tunability; (5) Complex oxides fail to address the issue of radiation losses in THz metamaterials.

Singh, Ranjan [Los Alamos National Laboratory; Xiong, Jie [Los Alamos National Laboratory; Azad, Md A. [Los Alamos National Laboratory; Yang, Hao [Los Alamos National Laboratory; Trugman, Stuart A. [Los Alamos National Laboratory; Jia, Quanxi [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; Chen, Houtong [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

285

Pressure induced high spin-low spin transition in FeSe superconductor studied by x-ray emission spectroscopy and ab initio calculations  

SciTech Connect

FeSe is a simple binary system in the iron based superconducting family and exhibits a significant pressure induced increase in the superconducting transition temperature (T{sub c}). In addition to pressure effect, spin fluctuations, magnetic ordering, and crystal structure all play vital roles in altering T{sub c}. Even though various experiments and theoretical simulations explain the connection among them and superconductivity, the interplay between these important parameters is still not clearly understood. Here, we report the pressure effect on the spin state of Fe in FeSe superconductor studied using synchrotron x-ray emission spectroscopy at ambient and low temperatures down to 8 K near T{sub c}. Pressure induced high spin to low spin transition was observed at both ambient and low temperatures with continuous suppression of Fe magnetic moments under increasing pressure. The spin transition is closely related to the pressure induced tetragonal to orthorhombic structural transition.

Kumar, Ravhi S.; Zhang, Yi; Xiao, Yuming; Baker, Jason; Cornelius, Andrew; Veeramalai, Sathishkumar; Chow, Paul; Chen, Changfeng; Zhao, Yusheng (UNLV); (CIW)

2011-09-20T23:59:59.000Z

286

Practical superconductor development for electrical power applications  

SciTech Connect

Development of useful high-critical-temperature (high-{Tc}) superconductors requires synthesis of superconducting compounds; fabrication of wires, tapes, and films from these compounds; production of composite structures that incorporate stabilizers or insulators; and design and testing of efficient components. This report describes technical progress of research and development efforts aimed at producing superconducting components based on the Y-Ba-Cu, Bi-Sr-Ca-Cu, Bi-Pb-Sr-Ca-Cu, and Tl-Ba-Ca-Cu oxides systems. Topics discussed are synthesis and heat treatment of high-{Tc} superconductors, formation of monolithic and composite wires and tapes, superconductor/metal connectors, characterization of structures and superconducting and mechanical properties, and fabrication and properties of thin films. Collaborations with industry and academia are also documented. 10 figs.

Goretta, K.C. (comp.)

1991-10-01T23:59:59.000Z

287

Acid Doped Membranes for High Temperature PEMFC  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on Acid Doped Membranes for High Temperature PEMFC to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

288

Joint Institute for High Temperatures  

National Nuclear Security Administration (NNSA)

Joint Institute for High Temperatures of Russian Academy of Sciences Moscow Institute of Physics and Technology Extended title Extended title Excited state of warm dense matter or Exotic state of warm dense matter or Novel form of warm dense matter or New form of plasma Three sources of generation similarity: solid state density, two temperatures: electron temperature about tens eV, cold ions keep original crystallographic positions, but electron band structure and phonon dispersion are changed, transient but steady (quasi-stationary for a short time) state of non-equilibrium, uniform plasmas (no reference to non-ideality, both strongly and weakly coupled plasmas can be formed) spectral line spectra are emitted by ion cores embedded in plasma environment which influences the spectra strongly,

289

High Reliability, High TemperatureThermoelectric Power Generation...  

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

Reliability, High TemperatureThermoelectric Power Generation Materials and Technologies High Reliability, High TemperatureThermoelectric Power Generation Materials and Technologies...

290

High temperature turbine engine structure  

DOE Patents (OSTI)

A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

Carruthers, William D. (Mesa, AZ); Boyd, Gary L. (Tempe, AZ)

1994-01-01T23:59:59.000Z

291

High temperature turbine engine structure  

DOE Patents (OSTI)

A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

Carruthers, William D. (Mesa, AZ); Boyd, Gary L. (Tempe, AZ)

1993-01-01T23:59:59.000Z

292

High temperature turbine engine structure  

DOE Patents (OSTI)

A high temperature ceramic/metallic turbine engine includes a metallic housing which journals a rotor member of the turbine engine. A ceramic disk-like shroud portion of the engine is supported on the metallic housing portion and maintains a close running clearance with the rotor member. A ceramic spacer assembly maintains the close running clearance of the shroud portion and rotor member despite differential thermal movements between the shroud portion and metallic housing portion.

Carruthers, William D. (Mesa, AZ); Boyd, Gary L. (Tempe, AZ)

1992-01-01T23:59:59.000Z

293

Pseudogap in a thin film of a conventional superconductor.  

SciTech Connect

A superconducting state is characterized by the gap in the electronic density of states, which vanishes at the superconducting transition temperature T{sub c}. It was discovered that in high-temperature superconductors, a noticeable depression in the density of states, the pseudogap, still remains even at temperatures above T{sub c}. Here, we show that a pseudogap exists in a conventional superconductor, ultrathin titanium nitride films, over a wide range of temperatures above T{sub c}. Our study reveals that this pseudogap state is induced by superconducting fluctuations and favoured by two-dimensionality and by the proximity to the transition to the insulating state. A general character of the observed phenomenon provides a powerful tool to discriminate between fluctuations as the origin of the pseudogap state and other contributions in the layered high-temperature superconductor compounds.

Sacepe, B.; Chapelier, C.; Baturina, T. I.; Vinokur, V. M.; Baklanov, M. R.; Sanquer, M. (Materials Science Division); (CEA-INAC/UJF-Grenoble); (A.V. Rzhanov Inst. Semiconductor Physics); (IMEC)

2010-12-01T23:59:59.000Z

294

Ultra High Temperature | Open Energy Information  

Open Energy Info (EERE)

Ultra High Temperature Ultra High Temperature Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Sanyal Temperature Classification: Ultra High Temperature Dictionary.png Ultra High Temperature: No definition has been provided for this term. Add a Definition Sanyal Temp Classification This temperature scheme was developed by Sanyal in 2005 at the request of DOE and GEA, as reported in Classification of Geothermal Systems: A Possible Scheme. Extremely Low Temperature Very Low Temperature Low Temperature Moderate Temperature High Temperature Ultra High Temperature Steam Field Reservoir fluid greater than 300°C is considered by Sanyal to be "ultra high temperature". "Such reservoirs are characterized by rapid development of steam saturation in the reservoir and steam fraction in the mobile fluid phase upon

295

Materials Characterization Capabilities at the High Temperature...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Characterization Capabilities at the High Temperature Materials Laboratory: Focus on Carbon Fiber and Composites Materials Characterization Capabilities at the High...

296

Aluminum-stabilized NB3SN superconductor  

DOE Patents (OSTI)

An aluminum-stabilized Nb.sub.3 Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb.sub.3 Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.

Scanlan, Ronald M. (Livermore, CA)

1988-01-01T23:59:59.000Z

297

Synthesis of highly phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor  

DOE Patents (OSTI)

An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor are disclosed. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor. 5 figs.

Dorris, S.E.; Poeppel, R.B.; Prorok, B.C.; Lanagan, M.T.; Maroni, V.A.

1994-10-11T23:59:59.000Z

298

Synthesis of highly phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor  

DOE Patents (OSTI)

An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor.

Dorris, Stephen E. (La Grange Park, IL); Poeppel, Roger B. (Glen Ellyn, IL); Prorok, Barton C. (Harrisville, PA); Lanagan, Michael T. (Woodridge, IL); Maroni, Victor A. (Naperville, IL)

1994-01-01T23:59:59.000Z

299

High-field Nb{sub 3}Sn superconductors prepared through a new route  

SciTech Connect

Nb{sub 3}Sn superconductors have been prepared through Nb{sub 6}Sn{sub 5} compound powder synthesized by a melt diffusion process from Nb and Sn powders. The Nb{sub 6}Sn{sub 5} powder was mixed with Nb powder in a ball mill. The resulting mixed powder was encased in a Ta tube, and fabricated into a tape. The mechanical mixing of Nb{sub 6}Sn{sub 5} and Nb powder promotes the formation of A15 Nb{sub 3}Sn phase in the subsequent heat treatment, and improves superconducting performance. The Nb{sub 3}Sn tape shows an upper critical field B{sub c2} of nearly 25T at 4.2K after the reaction at 900{degrees}C. The B{sub c2} is still increased by Ti doping. A small amount of Cu addition decreases the optimum reaction temperature to 850{degrees}C. Present Nb{sub 3}Sn specimen exhibits considerably larger normal state resistivity than that of bronze-processed Nb{sub 3}Sn, which may be the origin of enhanced B{sub c2} in the present Nb{sub 3}Sn specimen.

Tachikawa, K.; Natsuume, M.; Tomori, H.; Kuroda, Y. [Tokai Univ., Kanagawa (Japan)] [and others

1997-06-01T23:59:59.000Z

300

High Temperature Mechanical Properties as Design Parameters  

Science Journals Connector (OSTI)

...corrosion resistance or high proof strength...development of more efficient power plant, process...Figure 2 shows a high temperature bolt...S.O.) of a Boiler Code (I968...power plant for high temperature pipework, boiler headers, valve...

1976-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

National High Magnetic Field Laboratory - Scientist Profiles...  

NLE Websites -- All DOE Office Websites (Extended Search)

"Spatially resolved electronic structure inside and outside the vortex cores of a high-temperature superconductor", Nature 413, 501-504 (2001). 30. V. F. Mitrovi, E. E....

302

Sandia National Laboratories: High-Pressure and High-Temperature...  

NLE Websites -- All DOE Office Websites (Extended Search)

ClimateECClimateCarbon CaptureHigh-Pressure and High-Temperature Neutron Reflectometry Cell for Solid-Fluid Interface Studies High-Pressure and High-Temperature Neutron...

303

Test results of two high temperature superconducting sample coils  

SciTech Connect

Electrical measurements have been performed on two high temperature superconducting coils made by American Superconductor Corporation. One coil measured 24-mm ID, 59-mm OD, 50-mm long, and used 85-m long Y-124 tape conductor. The other coil measured 29-mm ID, 44-mm OD, 43-mm long, and used 35-m long Bi-2223 tape conductor. V-I curves were measured from room to helium temperature in a variable temperature cryostat cooled by helium gas in external fields up to 5 T. Without external field, the better performing Bi-2223 coil had a critical current, I{sub c} of 14.1 A (2820 A/cm{sup 2} over the conductor) at 4.2 K and 1.8 A (360 A/cm{sup 2}) at 77 K. At 5 T, I{sub c} was 4.9 A (980 A/cm{sup 2}) at 4.2 K and 2.0 A (400 A/cm{sup 2}) at 50 K. Reduced critical current, I{sub c}(B)/I{sub c}(0) vs field plots indicated that a single smooth curve could fit all the data of up to 50 K in temperature. The reduction in critical currents with external fields for the Y-124 coil was more than 80% at 1 T. For the Bi-2223 coil, it was about 38% at 1 T, and about 61% at 5 T.

Lue, J.W.; Schwenterly, S.W.; Lubell, M.S.; Luton, J.N. [Oak Ridge National Lab., TN (United States); Joshi, C.H.; Masur, L.J.; Podtburg, E.R. [American Superconductor Corp., Watertown, MA (United States)

1993-10-01T23:59:59.000Z

304

Consistency between the Lorentz-Force Independence of the Resistive Transition in the High-T-C Superconductors and the Standard Theory of Flux-Flow  

E-Print Network (OSTI)

PHYSICAL REVIEW B VOLUME 51, NUMBER 14 1 APRIL 1995-II Consistency between the Lorentz-force independence of the resistive transition in the high-T, superconductors and the standard theory of flux flow Zhidong Hao Tezas Center.... S. Ting Tezas Center for Superconductivity, University of Houston, Houston, Texas 77P04 (Received 6 October 1994) In a uniform flux-flow state of a type-II superconductor, (i) the resistivity tensor p,~ is independent of the dissipative transport...

HAO, ZD; Hu, Chia-Ren; TING, CS.

1995-01-01T23:59:59.000Z

305

High Temperature Superconductivity: Taming Serendipity (Thursday...  

NLE Websites -- All DOE Office Websites (Extended Search)

predictive design of new families of superconductors. She is recognized for her work on superconductorsemiconductor proximity effects, elucidating the physical properties of the...

306

High-temperature thermocouples and related methods  

DOE Patents (OSTI)

A high-temperature thermocouple and methods for fabricating a thermocouple capable of long-term operation in high-temperature, hostile environments without significant signal degradation or shortened thermocouple lifetime due to heat induced brittleness.

Rempe, Joy L. (Idaho Falls, ID); Knudson, Darrell L. (Firth, ID); Condie, Keith G. (Idaho Falls, ID); Wilkins, S. Curt (Idaho Falls, ID)

2011-01-18T23:59:59.000Z

307

High-temperature Pump Monitoring - High-temperature ESP Monitoring...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

at least at the outset, exclude new ideas. The drift issue appears to have brought a new search for materials into this research. * Objectives: Develop temperature and pressure...

308

Ceramic wire and coil made of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} high-temperature superconductor with a critical current density up to 75 A {center_dot}cm{sup {minus}2} at 77 K  

SciTech Connect

Processing parameters are refined and a route is found for fabricating wires, coils, and other lengthy electrotechnical elements form high-temperature superconducting ceramic YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}. The superconducting transition temperature of around 90 K and a critical current density in the terrestrial magnetic field of 35-75 A {center_dot} cm{sup {minus}2} at 77 K characterize the performance of the wire.

Basalaeva, T.S.; Ordan`yan, S.S.; Polonskii, Y.A. [St. Petersburg State Technical Univ. (Russian Federation)] [and others

1995-03-20T23:59:59.000Z

309

Agenda: High Temperature Membrane Working Group Meeting  

Energy.gov (U.S. Department of Energy (DOE))

Agenda for the High Temperature Membrane Working Group (HTMWG) meeting on May 18, 2009, in Arlington, Virginia

310

High Temperature Superconducting Underground Cable  

SciTech Connect

The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

Farrell, Roger, A.

2010-02-28T23:59:59.000Z

311

Temperature Instability in High-Tc Superconducting Wire Exposed to Thermal Disturbance  

Science Journals Connector (OSTI)

Abstract High-Tc superconductor wires/ conductors of longer lengths have emerged as one of the most promising candidates for several useful applications such as in utilities and in current lead powering large magnet system. These conductors are liquid nitrogen cooled and are much cheaper to operate. In the event of intrinsic thermal instability or cooling failure, irreversible transition to normal state may occur. These normal zones may propagate rapidly enough to cause transient heating leading to local hot spot and resulting in damage to the conductor/ magnet. In this paper, the mathematical formulation to determine the temperature distribution throughout the superconductor wire subjected to such transient disturbance is illustrated. The solution to the problem is achieved by using the method of separation of variables based on physically relevant initial conditions. The results are obtained in the series form in terms of Bessel's functions and are illustrated numerically for a technical yttrium barium copper oxide (YBCO) superconductor wire. Also it is found that even for a steady state heat transfer of 500W m2 K1, the conductor temperature rises above Tc in less than 10sec of the thermal disturbance.

Ziauddin Khan; Subrata Pradhan; Irfan Ahmed

2014-01-01T23:59:59.000Z

312

An internal winding high temperature heater  

Science Journals Connector (OSTI)

An internal winding high temperature heater ... General principles are outlined for the construction of compact heaters that are suitable for heating small containers or reaction vessels at constant temperature and up to about 1000 C. ...

A. J. Delbouille; E. G. Derouane

1973-01-01T23:59:59.000Z

313

Superconductor-Correlated metal-Superconductor Josephson junctions  

E-Print Network (OSTI)

Superconductor-Correlated metal- Superconductor Josephson junctions for high-speed digital. Freericks, Georgetown University, Josephson Junction talk, 2002 #12;Josephson Tunnel Junctions). J. K. Freericks, Georgetown University, Josephson Junction talk, 2002 S I S I I V V Ic #12

Freericks, Jim

314

Superconductor-Correlated metal-Superconductor Josephson junctions  

E-Print Network (OSTI)

Superconductor-Correlated metal- Superconductor Josephson junctions for high-speed digital. Freericks, Georgetown University, Josephson Junction talk, 2002 #12;Digital Electronics and RSFQ logic, Georgetown University, Josephson Junction talk, 2002 X X Binary 0, no flux Binary 1, one flux quantum #12

Freericks, Jim

315

Superconductor-Correlated metal-Superconductor Josephson junctions  

E-Print Network (OSTI)

Superconductor-Correlated metal- Superconductor Josephson junctions for high-speed digital. Freericks, Georgetown University, Josephson Junction talk, 2003 #12;Digital Electronics and RSFQ logic, Georgetown University, Josephson Junction talk, 2003 X X Binary 0, no flux Binary 1, one flux quantum #12

Freericks, Jim

316

High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems  

Energy.gov (U.S. Department of Energy (DOE))

High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems presentation at the April 2013 peer review meeting held in Denver, Colorado.

317

High Temperature Solar Splitting of Methane  

E-Print Network (OSTI)

-term commercialization opportunities #12;Why Use Solar Energy?Why Use Solar Energy? · High concentrations possible (>1000High Temperature Solar Splitting of Methane to Hydrogen and Carbon High Temperature Solar Splitting and worldwide) ­ Sufficient to power the world (if we choose to) · Advantages tradeoff against collection area

318

Nanostructured High Temperature Bulk Thermoelectric Energy Conversion...  

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

Efficient Automotive Waste Heat Recovery Multi-physics modeling of thermoelectric generators for waste heat recovery applications Nanostructured High-Temperature Bulk...

319

High Temperature Thermoelectric Materials Characterization for...  

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

2009 -- Washington D.C. lmp06wang.pdf More Documents & Publications High-Temperature Thermoelectric Materials Characterization for Automotive Waste Heat Recovery: Success...

320

Materials Characterization Capabilities at the High Temperature...  

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

Laboratory and HTML User Program Success Stories Materials Characterization Capabilities at the High Temperature Materials Laboratory: Focus on Carbon Fiber and Composites...

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

High Temperature Materials Laboratory (HTML) - PSD Directorate  

NLE Websites -- All DOE Office Websites (Extended Search)

filler A National Resource for Collaborative Materials Research The High Temperature Materials Laboratory (HTML) User Program is on hiatus due to federal budget reductions....

322

Detection of surface impurity phases in high T.sub.C superconductors using thermally stimulated luminescence  

DOE Patents (OSTI)

Detection of surface impurity phases in high-temperature superconducting materials. Thermally stimulated luminescence has been found to occur in insulating impurity phases which commonly exist in high-temperature superconducting materials. The present invention is sensitive to impurity phases occurring at a level of less than 1% with a probe depth of about 1 .mu.m which is the region of interest for many superconductivity applications. Spectroscopic and spatial resolution of the emitted light from a sample permits identification and location of the impurity species. Absence of luminescence, and thus of insulating phases, can be correlated with low values of rf surface resistance.

Cooke, D. Wayne (Los Alamos, NM); Jahan, Muhammad S. (Bartlett, TN)

1989-01-01T23:59:59.000Z

323

Energy Gaps in the Failed High-Tc Superconductor La_1.875Ba_0.125Cu_O4  

SciTech Connect

A central issue on high-T{sub c} superconductivity is the nature of the normal-state gap (pseudogap) in the underdoped regime and its relationship with superconductivity. Despite persistent efforts, theoretical ideas for the pseudogap evolve around fluctuating superconductivity, competing order and spectral weight suppression due to many-body effects. Recently, while some experiments in the superconducting state indicate a distinction between the superconducting gap and pseudogap, others in the normal state, either by extrapolation from high-temperature data or directly from La{sub 1.875}Ba{sub 0.125}CuO{sub 4} (LBCO-1/8) at low temperature, suggest the ground-state pseudogap is a single gap of d-wave form. Here we report angle-resolved photoemission (ARPES) data from LBCO-1/8, collected with improved experimental conditions, that reveal the ground-state pseudogap has a pronounced deviation from the simple d-wave form. It contains two distinct components: a d-wave component within an extended region around the node and the other abruptly enhanced close to the antinode, pointing to a dual nature of the pseudogap in this failed high-T{sub c} superconductor which involves a possible precursor pairing energy scale around the node and another of different but unknown origin near the antinode.

Tanaka, K.

2011-08-19T23:59:59.000Z

324

Energy Gaps in the Failed High-Tc Superconductor La1.875Ba0.125CuO4  

SciTech Connect

A central issue in high-T{sub c} superconductivity is the nature of the normal-state gap (pseudogap) in the underdoped regime and its relationship with superconductivity. Despite persistent efforts, theoretical ideas for the pseudogap evolve around fluctuating superconductivity, competing order, and spectral weight suppression due to many-body effects. Recently, although some experiments in the superconducting state indicate a distinction between the superconducting gap and pseudogap, others in the normal state, either by extrapolation from high-temperature data or directly from La{sub 1.875)Ba{sub 0.125}CuO{sub 4} (LBCO-1/8) at low temperature, suggest the ground-state pseudogap is a single gap of d-wave form. Here, we report angle-resolved photoemission data from LBCO-1/8, collected with improved experimental conditions, that reveal the ground-state pseudogap has a pronounced deviation from the simple d-wave form. It contains two distinct components: a d-waev component within an extended region around the node and the other abruptly enhanced close to the antinode, pointing to a dual nature of the pseudogap in this failed high-T{sub c} superconductor that involves a possible precursor-pairing energy scale around the node and another of different but unknown origin near the antinode.

Not Available

2011-08-11T23:59:59.000Z

325

Observation of magnetic field lines in the vicinity of a superconductor with the naked eye  

E-Print Network (OSTI)

Meissner effect and pinning effect are clearly observed with the naked eye. A GdBaCuO high-temperature superconductor (HTS) disk fabricated by Nippon Steel Corporation, a 100mm cubic NdFeB sintered magnet, and iron wires coated by colored are used. When the HTS is put in the magnetic field of the magnet, it can be observed by the wires that the magnetic field lines are excluded from the superconductor (Meissner effect) as well as are pinned in the superconductor (pinning effect).

Yoshihiko Saito

2008-05-26T23:59:59.000Z

326

Development of Designer Diamond Technology for High Pressure High Temperature Experiments in Support of Stockpile Stewardship Program  

SciTech Connect

The role of nitrogen in the fabrication of designer diamond was systematically investigated by adding controlled amount of nitrogen in hydrogen/methane/oxygen plasma. This has led to a successful recipe for reproducible fabrication of designer diamond anvils for high-pressure high-temperature research in support of stockpile stewardship program. In the three-year support period, several designer diamonds fabricated with this new growth chemistry were utilized in high-pressure experiments at UAB and Lawrence Livermore National Laboratory. The designer diamond anvils were utilized in high-pressure studies on heavy rare earth metals, high pressure melting studies on metals, and electrical resistance measurements on iron-based layered superconductors under high pressures. The growth chemistry developed under NNSA support can be adapted for commercial production of designer diamonds.

Vohra, Yogesh, K.

2009-10-28T23:59:59.000Z

327

High temperature solar selective coatings  

DOE Patents (OSTI)

Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

Kennedy, Cheryl E

2014-11-25T23:59:59.000Z

328

High Temperature, High Pressure Devices for Zonal Isolation in...  

Open Energy Info (EERE)

remotely and autonomous deployable structures for space and our high temperature composite technology developed for downhole applications. These devices offer several...

329

High-Temperature-High-Volume Lifting for Enhanced Geothermal...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Norman Turnquist GE Global Research High Temperature Tools and Sensors, Down-hole Pumps and Drilling May 19, 2010 This presentation does not contain any proprietary...

330

Symposium on high temperature and materials chemistry  

SciTech Connect

This volume contains the written proceedings of the Symposium on High Temperature and Materials Chemistry held in Berkeley, California on October 24--25, 1989. The Symposium was sponsored by the Materials and Chemical Sciences Division of Lawrence Berkeley Laboratory and by the College of Chemistry of the University of California at Berkeley to discuss directions, trends, and accomplishments in the field of high temperature and materials chemistry. Its purpose was to provide a snapshot of high temperature and materials chemistry and, in so doing, to define status and directions.

Not Available

1989-10-01T23:59:59.000Z

331

Chemistry and Electronic Structure of Iron-Based Superconductors  

SciTech Connect

The solid state provides a richly varied fabric for intertwining chemical bonding, electronic structure, and magnetism. The discovery of superconductivity in iron pnictides and chalcogenides has revealed new aspects of this interplay, especially involving magnetism and superconductivity. Moreover, it has challenged prior thinking about high-temperature superconductivity by providing a set of materials that differ in many crucial aspects from the previously known cuprate superconductors. Here we review some of what is known about the superconductivity and its interplay with magnetism, chemistry, and electronic structure in Fe-based superconductors.

Safa-Sefat, Athena [ORNL; Singh, David J [ORNL

2011-01-01T23:59:59.000Z

332

NMR Characterization of Sulphur Substitution Effects in the KxFe2?ySe2?zSz High-Tc Superconductor  

SciTech Connect

We present a {sup 77}Se NMR study of the effect of S substitution in the high-T{sub c} superconductor K{sub x}Fe{sub 2-y}Se{sub 2-z}S{sub z} in a temperature range up to 250 K. We examine two S concentrations, with z = 0.8 (T{sub c} {approx} 26 K) and z = 1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the K{sub x}Fe{sub 2}Se{sub 2} sample due to local disorder in the Se environment. Our Knight shift {sup 77}K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition, S substitution progressively suppresses low-frequency spin fluctuations. None of the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near T{sub c} in 1/T{sub 1}T, as seen in FeSe.

Petrovic C.; Torchetti, D.A.; Imai, T.; Lei, H.C.

2012-04-17T23:59:59.000Z

333

Noise Absorbing High-Temperature Insulation  

Science Journals Connector (OSTI)

Until recently simple heat shields on the engine, in the engine space or on the subframe of a vehicle had given protection against radiant heat from hot components. Today, complex high-temperature insulation syst...

Peter Cappellucci

2013-07-01T23:59:59.000Z

334

Thermodynamics of high-temperature nuclear fuel  

Science Journals Connector (OSTI)

A method for performing a thermodynamic analysis of the high-temperature nuclear fuel using the ASTA computer program is substantiated. Calculations of the chemical composition and pressure of the gas phase of...

I. A. Belov; A. S. Ivanov

335

High Temperature Corrosion Test Facilities and High Pressure Test  

NLE Websites -- All DOE Office Websites (Extended Search)

High Temperature High Temperature Corrosion Test Facilities and High Pressure Test Facilities for Metal Dusting Test Facilities for Metal Dusting Overview Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr High Temperature Corrosion Test Facilities and High Pressure Test Facilities for Metal Dusting Six corrosion test facilities and two thermogravimetric systems for conducting corrosion tests in complex mixed gas environments, in steam and in the presence of deposits, and five facilities for metal dusting degradation Bookmark and Share The High Temperature Corrosion Test Facilities and High Pressure Test Facilities for Metal Dusting include: High Pressure Test Facility for Metal Dusting Resistance:

336

High temperature thermometric phosphors for use in a temperature sensor  

DOE Patents (OSTI)

A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.(y), wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN); Gillies, George T. (Earlysville, VA)

1998-01-01T23:59:59.000Z

337

Massive Energy Storage in Superconductors (SMES) | U.S. DOE Office of  

NLE Websites -- All DOE Office Websites (Extended Search)

Massive Energy Storage in Superconductors (SMES) Massive Energy Storage in Superconductors (SMES) Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » August 2013 Massive Energy Storage in Superconductors (SMES) Novel high temperature superconductor magnet technology charts new territory. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of Brookhaven National Laboratory A toroid SMES system consisting of a number of high field coils made with

338

Apparatus and method for high temperature viscosity and temperature measurements  

DOE Patents (OSTI)

A probe for measuring the viscosity and/or temperature of high temperature liquids, such as molten metals, glass and similar materials comprises a rod which is an acoustical waveguide through which a transducer emits an ultrasonic signal through one end of the probe, and which is reflected from (a) a notch or slit or an interface between two materials of the probe and (b) from the other end of the probe which is in contact with the hot liquid or hot melt, and is detected by the same transducer at the signal emission end. To avoid the harmful effects of introducing a thermally conductive heat sink into the melt, the probe is made of relatively thermally insulative (non-heat-conductive) refractory material. The time between signal emission and reflection, and the amplitude of reflections, are compared against calibration curves to obtain temperature and viscosity values.

Balasubramaniam, Krishnan (Mississippi State, MS); Shah, Vimal (Houston, TX); Costley, R. Daniel (Mississippi State, MS); Singh, Jagdish P. (Mississippi State, MS)

2001-01-01T23:59:59.000Z

339

Resonance in the Electron-doped High-Tc Superconductor Pr0.88LaCe0.12CuO4-?  

SciTech Connect

In conventional superconductors, the interaction that pairs the electrons to form the superconducting state is mediated by lattice vibrations (phonons). In high-transition-temperature (high-T{sub c}) copper oxides, it is generally believed that magnetic excitations might play a fundamental role in the superconducting mechanism because superconductivity occurs when mobile 'electrons' or 'holes' are doped into the antiferromagnetic parent compounds. Indeed, a sharp magnetic excitation termed 'resonance' has been observed by neutron scattering in a number of hole-doped materials. The resonance is intimately related to superconductivity, and its interaction with charged quasi-particles observed by photoemission, optical conductivity, and tunnelling suggests that it might play a part similar to that of phonons in conventional superconductors. The relevance of the resonance to high-T{sub c} superconductivity, however, has been in doubt because so far it has been found only in hole-doped materials. Here we report the discovery of the resonance in electron-doped superconducting Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} (T{sub c} = 24 K). We find that the resonance energy (E{sub r}) is proportional to T{sub c} via E{sub r} {approx} 5.8k{sub B}T{sub c} for all high-T{sub c} superconductors irrespective of electron- or hole-doping. Our results demonstrate that the resonance is a fundamental property of the superconducting copper oxides and therefore must be essential in the mechanism of superconductivity.

Wilson, Stephen D. [University of Tennessee, Knoxville (UTK); Dai, Pengcheng [University of Tennessee, Knoxville (UTK); Li, Shiliang [University of Tennessee, Knoxville (UTK); Chi, Songxue [University of Tennessee, Knoxville (UTK); Kang, H. J. [University of Tennessee, Knoxville (UTK); Lynn, J. W. [National Institute of Standards and Technology (NIST)

2006-01-01T23:59:59.000Z

340

Correlation between superconductivity and structural properties under high pressure of iron pnictide superconductor Ce[subscript 0.6]Y[subscript 0.4]FeAsO[subscript 0.8]F[subscript 0.2  

SciTech Connect

We report here the pressure dependence of the electrical resistivity and magnetic susceptibility of polycrystalline Ce{sub 0.6}Y{sub 0.4}FeAsO{sub 0.8}F{sub 0.2} superconductor in the temperature range 4 K to 300 K up to 8 GPa. In-situ high pressure-low temperature x-ray diffraction was performed at 8 K up to 32 GPa using synchrotron x-rays with helium pressure medium. The results show that the applied pressure slightly increases the T{sub c} up to 1 GPa and then it decreases on further pressure increase. The reduction of superconducting transition temperature occurs with a transition to a collapsed tetragonal phase and may be associated with a possible valence change of Ce.

Kanagaraj, M.; Arumugam, S.; Kumar, Ravhi S.; Selvan, N.R. Tamil; Muthu, S. Esakki; Prakash, J.; Thakur, Gohil S.; Yoshino, H.; Murata, K.; Matsubayashi, K.; Uwatoko, Y.; Sinogeikin, S.; Cornelius, Andrew; Ganguli, A.K.; Zhao, Yusheng (IIT-India); (UNLV); (U of Tokyo); (Bharathidasan); (Osaka)

2012-02-28T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Radiation detector using a bulk high T[sub c] superconductor  

DOE Patents (OSTI)

A radiation detector is provided, wherein a bulk high T[sub c] superconducting sample is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil which is coupled by an input coil to an rf SQUID. 4 figures.

Artuso, J.F.; Franks, L.A.; Hull, K.L.; Symko, O.G.

1993-12-07T23:59:59.000Z

342

Superconductor bearings, flywheels and transportation  

Science Journals Connector (OSTI)

This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10kN axially and 4.5kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600kg rotor of a 5kWh/250kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTSFESS projects. A small-scale compact YBCO bearing with insitu Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10mm distance during one-day operation without refilling LN2. More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

F N Werfel; U Floegel-Delor; R Rothfeld; T Riedel; B Goebel; D Wippich; P Schirrmeister

2012-01-01T23:59:59.000Z

343

High Temperature, Permanent Magnet Biased Magnetic Bearings  

E-Print Network (OSTI)

performance, high speed and high temperature applications like space vehicles, jet engines and deep sea equipment. The bearing system had a target design to carry a load equal to 500 lb-f (2225N). Another objective was to design and build a test rig fixture...

Gandhi, Varun R.

2010-07-14T23:59:59.000Z

344

FABRICATION AND PROPERTIES OF HIGH Jc YBaCuO SUPERCONDUCTOR BY (MTG) PROCESS  

Science Journals Connector (OSTI)

Superconducting YBaCuO bulk materials were fabricated by melttextured growth (MTG) method, where cooling slowly under temperature gradient produces an aligned structure exhibiting high Jc value. The critical current density was measured by continuous dc fourprobe method with criterion of 1?V/cm. Jc value has reached 23, 800 A/cm2 at 77K under 2T magnetic field perpendicular to the current. The magnetic field dependences of Jc from 1 to 7 Tesla show the anisotropy for two orientations (H?I, H?ab plane and H?I, H//ab plane). The Xray diffraction patterns show the crystals preferentially aligned. The SEM and TEM observations of the MTG sample reveal that the sample has dense layeredstructure with regular alignment of plateshaped crystals. Twinning planes of fairly high density exist. A great quantity of dislocations, dislocation loops and stacking faults exist around 211 phase. These crystal defects may be main flux pinning centers. We have measured the zerofield cooled (ZFC) and the field cooled (FC) magnetizations as functions of temperature at various external dc magnetic field. The dependence of irreversibility point T* on 2/3 power of field H for MTG sample was demonstrated. The flux jumping was found in the hysteresis loop below 10K.

Ren Hongtao; Xiao Ling; He Qing; Wang Ruikun; Chang Shian; Yu Dingan; Cui Changgeng; Li Shanlin; Wei Chongde; Dai Yuandong

1991-01-01T23:59:59.000Z

345

High Temperature Materials for Aerospace Applications  

E-Print Network (OSTI)

below 430 ?C for exposure times up to 20 minutes. Transition-metal carbides were initially synthesized by carbothermal reduction of transition-metal halides and polymer precursor mixtures, at temperatures that range from 900 to 1500 ?C in an argon... ........................................ 20 2.3 Present/Future Aerospace Applications ......................................... 24 2.4 Ultra-High Temperature Materials ................................................. 27 2.4.1 Transition-Metal Carbides...

Adamczak, Andrea Diane

2011-08-08T23:59:59.000Z

346

High Temperature Cements | Open Energy Information  

Open Energy Info (EERE)

High Temperature Cements High Temperature Cements Jump to: navigation, search Geothermal ARRA Funded Projects for High Temperature Cements Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":200,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026 further results","default":"","geoservice":"google","zoom":false,"width":"600px","height":"350px","centre":false,"layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","icon":"","visitedicon":"","forceshow":true,"showtitle":true,"hidenamespace":false,"template":false,"title":"","label":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"locations":[{"text":"

347

High Temperature Membrane & Advanced Cathode Catalyst Development  

SciTech Connect

Current project consisted of three main phases and eighteen milestones. Short description of each phase is given below. Table 1 lists program milestones. Phase 1--High Temperature Membrane and Advanced Catalyst Development. New polymers and advanced cathode catalysts were synthesized. The membranes and the catalysts were characterized and compared against specifications that are based on DOE program requirements. The best-in-class membranes and catalysts were downselected for phase 2. Phase 2--Catalyst Coated Membrane (CCM) Fabrication and Testing. Laboratory scale catalyst coated membranes (CCMs) were fabricated and tested using the down-selected membranes and catalysts. The catalysts and high temperature membrane CCMs were tested and optimized. Phase 3--Multi-cell stack fabrication. Full-size CCMs with the down-selected and optimized high temperature membrane and catalyst were fabricated. The catalyst membrane assemblies were tested in full size cells and multi-cell stack.

Protsailo, Lesia

2006-04-20T23:59:59.000Z

348

Manufacturing Barriers to High Temperature PEM Commercialization  

NLE Websites -- All DOE Office Websites (Extended Search)

9/2011 9/2011 1 BASF Fuel Cell, Inc. Manufacturing Barriers to high temperature PEM commercialization 39 Veronica Ave Somerset , NJ 08873 Tel : (732) 545-5100 9/9/2011 2 Background on BASF Fuel Cell  BASF Fuel Cell was established in 2007, formerly PEMEAS Fuel Cells (including E-TEK)  Product line is high temperature MEAs (Celtec ® P made from PBI-phosphoric acid)  Dedicated a new advanced pilot manufacturing facility in Somerset NJ May 2009. Ribbon-cutting hosted by Dr. Kreimeyer (BASF BoD, right) and attended by various US pubic officials including former NJ Governor Jon Corzine (left) 9/9/2011 3 Multi-layer product of membrane (polybenzimidazole and phosphoric acid), gas diffusion material and catalysts Unique characteristics:  High operating temperature

349

Design of a high-current downlink using Bi-based superconductors  

SciTech Connect

Recent processing developments in Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}0{sub x} (BSCCO-2223) bars have produced bulk BSCCO-2223 bars with properties advantageous for power applications. Cold isostatically pressed (CIP) and sinter-forged BSCCO-2223 both have low AC loss, which make them desirable for use in power devices. Thermal conductivity of the CIP bars is lower than that of the previously used sinter-forged samples by a factor of 2. CIP bars with cross-sectional areas of =0.75 cm{sup 2} and carrying 250 A RMS transport current have AC loss values of 30 pJ/cycle-cm at 50 Hz and 77 K. A pair of prototype downlinks were designed and built with sinter forged bars to deliver a continuous AC current of 1500 A over a temperature gradient of 77 to 4.2 K while delivering about -200 MW of heat to the liquid-helium-cooled end. This paper will discuss the design considerations and modeling of downlinks, which supply high AC currents over the 77 to 4.2 K temperature gradient with low thermal losses.

Fisher, B.L.; Lanagan, M.T.; Balachandran, U. [Argonne National Lab., IL (United States). Energy Technology Div.; Honjo, S.; Hara, T. [Tokyo Electric Power Co., Yokohama (Japan)

1996-08-01T23:59:59.000Z

350

High temperature superconductive flux gate magnetometer  

SciTech Connect

This paper proposes a different type of HTS superconducting magnetometer based on the non-linear magnetic behavior of bulk HTS materials. The device design is based on the generation of second harmonics which arise as a result of non-linear magnetization observed in Type-II superconductors. Even harmonics are generated from the non-linear interaction of an ac excitation signal with an external DC magnetic field which acts as a bias signal.

Gershenson, M. (Naval Coastal Systems Center, Panama City, FL (United States))

1991-03-01T23:59:59.000Z

351

Radiation detector using a bulk high T.sub.c superconductor  

DOE Patents (OSTI)

A radiation detector (10) is provided, wherein a bulk high T.sub.c superconducting sample (11) is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil (12) which is coupled by an input coil (15) to an rf SQUID (16).

Artuso, Joseph F. (Santa Barbara, CA); Franks, Larry A. (Santa Barbara, CA); Hull, Kenneth L. (Ventura, CA); Symko, Orest G. (Salt Lake City, UT)

1993-01-01T23:59:59.000Z

352

High temperature storage loop : final design report.  

SciTech Connect

A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650%C2%B0C) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOE's SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

Gill, David Dennis; Kolb, William J.

2013-07-01T23:59:59.000Z

353

Recent developments in filamentary compound superconductors  

SciTech Connect

Filamentary A15 Compound superconductors are indispensable for the generation of magnetic fields over 10 T at 4.2 K. The fabrication of Nb/sub 3/ Sn and Va/sub 3/Ga wires is based on the composite process in which a composite of niobium or vanadium cores in a Cu-Sn or Cu-Ca solid-solution alloy matrix is fabricated and then heat-treated. The addition of a third element, such as aluminum, titanium, hafnium, or magnesium, to the niobium or vanadium core affects the transition temperature and the upper critical field and produces fine Nb/sub 3/ Sn grains in an A15 compound. Other effects resulting from such an addition, in areas such as critical current densities in high magnetic fields and stress, are analyzed. Use of the in situ technique for the fabrication of filamentary A15 superconductors as an alternative to the composite process is described. The fabrication and potential of multifilamentary C15 V/sub 2/ (Hf or Zr) wires as a high-field superconductor for magnetic fusion reactor use are presented. Graphs and data analyses are included.

Tachikawa, I.T.

1982-01-01T23:59:59.000Z

354

High-Temperature-High-Volume Lifting | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » High-Temperature-High-Volume Lifting Jump to: navigation, search Geothermal ARRA Funded Projects for High-Temperature-High-Volume Lifting Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":200,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

355

Improved Martensitic Steel for High Temperature Applications  

NLE Websites -- All DOE Office Websites (Extended Search)

Improved Martensitic Steel Improved Martensitic Steel for High Temperature Applications Opportunity Research is active on the patented technology, titled "Heat-Treated 9 Cr-1 Mo Steel for High Temperature Application." This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory (NETL). Overview The operating efficiency of coal-fired power plants is directly related to combustion system temperature and pressure. Incorporation of ultra- supercritical (USC) steam conditions into new or existing power plants can achieve increased efficiency and reduce coal consumption, while reducing carbon dioxide emissions as well as other pollutants. Traditionally used materials do not possess the optimal characteristics for operation

356

Magnetism in Iron at High Temperatures  

Science Journals Connector (OSTI)

Magnetism in iron at high temperature is investigated by calculating the total electronic band-structure energy for four types of spin arrangements. A slow smooth spatial variation of spin direction costs relatively little energy and the atomic moment m is reduced only ? 10%. More rapid variations have considerably higher energy, which may explain the high degree of short-range order and small ?m observed at T?TC. Other aspects are also discussed.

M. V. You; V. Heine; A. J. Holden; P. J. Lin-Chung

1980-05-12T23:59:59.000Z

357

High Temperature, High Pressure Devices for Zonal Isolation in Geothermal  

Open Energy Info (EERE)

Temperature, High Pressure Devices for Zonal Isolation in Geothermal Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title High Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Zonal Isolation Project Description For Enhanced Geothermal Systems (EGS), high-temperature high-pressure zonal isolation tools capable of withstanding the downhole environment are needed. In these wells the packers must withstand differential pressures of 5,000 psi at more than 300°C, as well as pressures up to 20,000 psi at 200°C to 250°C. Furthermore, when deployed these packers and zonal isolation tools must form a reliable seal that eliminates fluid loss and mitigates short circuiting of flow from injectors to producers. At this time, general purpose open-hole packers do not exist for use in geothermal environments, with the primary technical limitation being the poor stability of existing elastomeric seals at high temperatures.

358

High-Temperature-High-Volume Lifting For Enhanced Geothermal Systems  

Open Energy Info (EERE)

Temperature-High-Volume Lifting For Enhanced Geothermal Systems Temperature-High-Volume Lifting For Enhanced Geothermal Systems Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title High-Temperature-High-Volume Lifting For Enhanced Geothermal Systems Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 High-Temperature-High-Volume Lifting Project Description The proposed scope of work is divided into three Phases. Overall system requirements will be established in Phase 1, along with an evaluation of existing lifting system capability, identification of technology limitations, and a conceptual design of an overall lifting system. In developing the system components in Phase 2, component-level tests will be conducted using GE facilities. Areas of development will include high-temperature drive system materials, journal and thrust bearings, and corrosion and erosion-resistant lifting pump components. Finally, in Phase 3, the overall lab-scale lifting system will be demonstrated in a flow loop that will be constructed at GE Global Research.

359

Potential applications of high temperature helium  

SciTech Connect

This paper discusses the DOE MHTGR-SC program`s recent activity to improve the economics of the MHTGR without sacrificing safety performance and two potential applications of high temperature helium, the MHTGR gas turbine plant and a process heat application for methanol production from coal.

Schleicher, R.W. Jr.; Kennedy, A.J.

1992-09-01T23:59:59.000Z

360

Potential applications of high temperature helium  

SciTech Connect

This paper discusses the DOE MHTGR-SC program's recent activity to improve the economics of the MHTGR without sacrificing safety performance and two potential applications of high temperature helium, the MHTGR gas turbine plant and a process heat application for methanol production from coal.

Schleicher, R.W. Jr.; Kennedy, A.J.

1992-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

The High-Temperature Oxidation of Propane  

Science Journals Connector (OSTI)

...research-article The High-Temperature Oxidation of Propane J. W. Falconer J. H. Knox Above 400 degrees C propane is oxidized by a two-stage degenerately...of propylene becomes important. While propane still in the main reacts to form propylene...

1959-01-01T23:59:59.000Z

362

Effect of unitary impurities on non-STM types of tunneling in high-T-c superconductors  

E-Print Network (OSTI)

Based on an extended Hubbard model, we present calculations of both the local (i.e., single-site) and spatially averaged differential tunneling conductance in d-wave superconductors containing nonmagnetic impurities in the unitary limit. Out results...

Zhu, JX; Ting, CS; Hu, Chia-Ren.

2000-01-01T23:59:59.000Z

363

High temperature intermetallic binders for HVOF carbides  

SciTech Connect

Gas turbines technology has a long history of employing the desirable high temperature physical attributes of ceramic-metallic (cermet) materials. The most commonly used coatings incorporate combinations of WC-Co and Cr{sub 3}C{sub 2}-NiCr, which have also been successfully utilized in other non-turbine coating applications. Increased turbine operating temperatures and other high temperature service conditions have made apparent the attractive notion of increasing the temperature capability and corrosion resistance of these coatings. In this study the intermetallic binder NiAl has been used to replace the cobalt and NiCr constituents of conventional WC and Cr{sub 3}C{sub 2} cermet powders. The composite carbide thermal spray powders were fabricated for use in the HVOF coating process. The structure of HVOF deposited NiAl-carbide coatings are compared directly to the more familiar WC-Co and Cr{sub 3}C{sub 2}-NiCr coatings using X-ray diffraction, back-scattered electron imaging (BEI) and electron dispersive spectroscopy (EDS). Hardness variations with temperature are reported and compared between the NiAl and Co/NiCr binders.

Shaw, K.G. [Xform, Inc., Cohoes, NY (United States); Gruninger, M.F.; Jarosinski, W.J. [Praxair Specialty Powders, Indianapolis, IN (United States)

1994-12-31T23:59:59.000Z

364

Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

ORNL's High Temperature ORNL's High Temperature Materials Laboratory Assists NASCAR Teams to someone by E-mail Share Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on Facebook Tweet about Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on Twitter Bookmark Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on Google Bookmark Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on Delicious Rank Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on Digg Find More places to share Vehicle Technologies Office: ORNL's High Temperature Materials Laboratory Assists NASCAR Teams on AddThis.com...

365

Syngas Enhanced High Efficiency Low Temperature Combustion for...  

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

Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines Syngas Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines A significant...

366

Vehicle Technologies Office Merit Review 2014: High-Temperature...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High-Temperature Air-Cooled Power Electronics Thermal Design Vehicle Technologies Office Merit Review 2014: High-Temperature Air-Cooled Power Electronics Thermal Design...

367

High Temperature Polymer Membrane Development at Argonne National...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Polymer Membrane Development at Argonne National Laboratory High Temperature Polymer Membrane Development at Argonne National Laboratory Summary of ANL's high temperature polymer...

368

High Temperature Fuel Cells in the European Union  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on High Temperature Fuel Cells in the European Union to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

369

Low and high Temperature Dual Thermoelectric Generation Waste...  

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

Low and high Temperature Dual Thermoelectric Generation Waste Heat Recovery System for Light-Duty Vehicles Low and high Temperature Dual Thermoelectric Generation Waste Heat...

370

High temperature membranes for DMFC (and PEFC) applications  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on High temperature membranes for DMFCs (and PEFCs) to the High Temperature Membrane Working Group, May 25, 2004 in Philadelphia, PA.

371

Development of Advanced High Temperature Fuel Cell Membranes  

Energy.gov (U.S. Department of Energy (DOE))

Presentation on Development of Advanced High Temperature Fuel Cell Membranes to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.

372

Development of a 100-Watt High Temperature Thermoelectric Generator...  

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

Generator Development of a 100-Watt High Temperature Thermoelectric Generator Test results for low and high temperature thermoelectric generators (TEG) those for a...

373

A Discussion of Conductivity Testing in High Temperature Membranes...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

A Discussion of Conductivity Testing in High Temperature Membranes (lessons learned in assessing transport) A Discussion of Conductivity Testing in High Temperature Membranes...

374

High Temperature Polymer Membrane Development at Argonne National Laboratory  

Energy.gov (U.S. Department of Energy (DOE))

Summary of ANLs high temperature polymer membrane work presented to the High Temperature Membrane Working Group Meeting, Orlando FL, October 17, 2003

375

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

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

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Nanostructured High-Temperature Bulk Thermoelectric Energy...

376

Microchannel High-Temperature Recuperator for Fuel Cell Systems...  

Office of Environmental Management (EM)

Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2014 Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2014 FuelCell...

377

Enhanced High and Low Temperature Performance of NOx Reduction...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Enhanced High and Low Temperature Performance of NOx Reduction Materials Enhanced High and Low Temperature Performance of NOx Reduction Materials 2013 DOE Hydrogen and Fuel Cells...

378

High Resolution and Low-Temperature Photoelectron Spectroscopy...  

NLE Websites -- All DOE Office Websites (Extended Search)

High Resolution and Low-Temperature Photoelectron Spectroscopy of an Oxygen-Linked Fullerene Dimer Dianion: C120O2-. High Resolution and Low-Temperature Photoelectron Spectroscopy...

379

Polyelectrolyte Materials for High Temperature Fuel Cells | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Polyelectrolyte Materials for High Temperature Fuel Cells Polyelectrolyte Materials for High Temperature Fuel Cells This presentation, which focuses on polyelectrolyte materials...

380

Compliant high temperature seals for dissimilar materials  

DOE Patents (OSTI)

A high temperature, gas-tight seal is formed by utilizing one or more compliant metallic toroidal ring sealing elements, where the applied pressure serves to activate the seal, thus improving the quality of the seal. The compliant nature of the sealing element compensates for differences in thermal expansion between the materials to be sealed, and is particularly useful in sealing a metallic member and a ceramic tube art elevated temperatures. The performance of the seal may be improved by coating the sealing element with a soft or flowable coating such as silver or gold and/or by backing the sealing element with a bed of fine powder. The material of the sealing element is chosen such that the element responds to stress elastically, even at elevated temperatures, permitting the seal to operate through multiple thermal cycles.

Rynders, Steven Walton (Fogelsville, PA); Minford, Eric (Laurys Station, PA); Tressler, Richard Ernest (Boalsburg, PA); Taylor, Dale M. (Salt Lake City, UT)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Thermal fuse for high-temperature batteries  

DOE Patents (OSTI)

A thermal fuse, preferably for a high-temperature battery, comprising leads and a body therebetween having a melting point between approximately 400.degree. C. and 500.degree. C. The body is preferably an alloy of Ag--Mg, Ag--Sb, Al--Ge, Au--In, Bi--Te, Cd--Sb, Cu--Mg, In--Sb, Mg--Pb, Pb--Pd, Sb--Zn, Sn--Te, or Mg--Al.

Jungst, Rudolph G. (Albuquerque, NM); Armijo, James R. (Albuquerque, NM); Frear, Darrel R. (Austin, TX)

2000-01-01T23:59:59.000Z

382

Establishment of Harrop, High-Temperature Viscometer  

SciTech Connect

This report explains how the Harrop, High-Temperature Viscometer was installed, calibrated, and operated. This report includes assembly and alignment of the furnace, viscometer, and spindle, and explains the operation of the Brookfield Viscometer, the Harrop furnace, and the UDC furnace controller. Calibration data and the development of the spindle constant from NIST standard reference glasses is presented. A simple operational procedure is included.

Schumacher, R.F.

1999-11-05T23:59:59.000Z

383

Polyelectrolyte Materials for High Temperature Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Polyelectrolyte Materials for High Polyelectrolyte Materials for High 3M (3M) Temperature Fuel Cells John B. Kerr Lawrence Berkeley National Laboratory (LBNL) Collaborators: Los Alamos National Laboratory (LANL). February 13, 2007 This presentation does not contain any proprietary or confidential information Team Members: Nitash Blasara, Rachel Segalman, Adam Weber (LBNL). Bryan Pivovar, James Boncella (LANL) Steve Hamrock Objectives * Investigate the use of solid polyelectrolyte proton conductors that do not require the presence of water. * Prepare solid electrolytes where only the proton moves. - Measure conductivity, mechanical/thermal properties of Nafion® and other polyelectrolytes doped with imidazoles. Compare with water doped materials. - Covalently attach imidazoles to side chains of ionomers with

384

NOVEL REFRACTORY MATERIALS FOR HIGH ALKALI, HIGH TEMPERATURE ENVIRONMENTS  

SciTech Connect

Refractory materials can be limited in their application by many factors including chemical reactions between the service environment and the refractory material, mechanical degradation of the refractory material by the service environment, temperature limitations on the use of a particular refractory material, and the inability to install or repair the refractory material in a cost effective manner or while the vessel was in service. The objective of this project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al 2O3 spinel or other similar magnesia/alumina containing unshaped refractory composition (castables, gunnables, shotcretes, etc) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, high-alkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries.

Hemrick, James Gordon [ORNL

2011-09-01T23:59:59.000Z

385

Density Functional Theory for Superconductors  

E-Print Network (OSTI)

Density Functional Theory for Superconductors N. N. LATHIOTAKIS,1,2 M. A. L. MARQUES,1,2,3 M. LU; density functional theory; critical temperature; exchange and correlation; phonon and theoretical chemistry is density functional theory (DFT). Its foundations were established in the mid-1960s

Gross, E.K.U.

386

Diamond switches for high temperature electronics  

SciTech Connect

Diamond switches are well suited for use in high temperature electronics. Laboratory feasibility of diamond switching at 1 kV and 18 A was demonstrated. DC blocking voltages up to 1 kV were demonstrated. A 50 {Omega} load line was switched using a diamond switch, with switch on-state resistivity {approx}7 {Omega}-cm. An electron beam, {approx}150 keV energy, {approx}2 {mu}s full width at half maximum was used to control the 5 mm x 5 mm x 100 {mu}m thick diamond switch. The conduction current temporal history mimics that of the electron beam. These data were taken at room temperature.

Prasad, R.R.; Rondeau, G.; Qi, Niansheng [Alameda Applied Sciences Corp., San Leandro, CA (United States)] [and others

1996-04-25T23:59:59.000Z

387

High and ultra high magnetic field studies of newly synthesized organic superconductors. Final report, 30 September 1992-29 September 1995  

SciTech Connect

To understand the nature of the superconducting state, the authors studied the new organic superconductor (BETS)2GaCl4, that was synthesized by their collaborator L. K. Montgomery. The BETS donor molecule is a variant of the BEDT molecule where four of the inner sulfur atoms are replaced with selenium atoms. The larger selenium atoms produce a larger overlap of the orbitals in the conducting sheets of the crystals and hence produce wider electronic bands. The authors used RF penetration depth measurements at 24 MHz initially to map out the H{sub c2} diagram of (BETS)2GaCl4. The measurements were much more successful than they expected yielding many details about the superconducting state and the vortex lattice. As an example, the authors were able to measure the pinning force potential, often called the Labush parameter, as a function of temperature from 100 mK to 4.5 K. Knowing this parameter enabled them to calculate a critical current at zero temperature of 2 x 10(exp 4) A/sq cm for this material.

Agosta, C.C.

1995-09-29T23:59:59.000Z

388

High Temperature Materials Laboratory third annual report  

SciTech Connect

The High Temperature Materials Laboratory has completed its third year of operation as a designated DOE User Facility at the Oak Ridge National Laboratory. Growth of the user program is evidenced by the number of outside institutions who have executed user agreements since the facility began operation in 1987. A total of 88 nonproprietary agreements (40 university and 48 industry) and 20 proprietary agreements (1 university, 19 industry) are now in effect. Sixty-eight nonproprietary research proposals (39 from university, 28 from industry, and 1 other government facility) and 8 proprietary proposals were considered during this reporting period. Research projects active in FY 1990 are summarized.

Tennery, V.J.; Foust, F.M.

1990-12-01T23:59:59.000Z

389

Superconductivity Program Overview High-Temperature Superconductivity  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SuperconducTiviTy program haS Three FocuS areaS: SuperconducTiviTy program haS Three FocuS areaS: SuperconducTiviTy applicaTionS Developing HTS-based electric power equipment such as transmission and distribution cables and fault current limiters Second-generaTion Wire developmenT Developing high-performance, low-cost, second- generation HTS wire at long lengths STraTegic reSearch Supporting fundamental research activities to better understand relationships between the microstructure of HTS materials and their ability to carry large electric currents over long lengths Superconductivity Program Overview High-Temperature Superconductivity for Electric Systems Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585

390

Thermal stability of high temperature structural alloys  

SciTech Connect

High temperature structural alloys were evaluated for suitability for long term operation at elevated temperatures. The effect of elevated temperature exposure on the microstructure and mechanical properties of a number of alloys was characterized. Fe-based alloys (330 stainless steel, 800H, and mechanically alloyed MA 956), and Ni-based alloys (Hastelloy X, Haynes 230, Alloy 718, and mechanically alloyed MA 758) were evaluated for room temperature tensile and impact toughness properties after exposure at 750 C for 10,000 hours. Of the Fe-based alloys evaluated, 330 stainless steel and 800H showed secondary carbide (M{sub 23}C{sub 6}) precipitation and a corresponding reduction in ductility and toughness as compared to the as-received condition. Within the group of Ni-based alloys tested, Alloy 718 showed the most dramatic structure change as it formed delta phase during 10,000 hours of exposure at 750 C with significant reductions in strength, ductility, and toughness. Haynes 230 and Hastelloy X showed significant M{sub 23}C{sub 6} carbide precipitation and a resulting reduction in ductility and toughness. Haynes 230 was also evaluated after 10,000 hours of exposure at 850, 950, and 1050 C. For the 750--950 C exposures the M{sub 23}C{sub 6} carbides in Haynes 230 coarsened. This resulted in large reductions in impact strength and ductility for the 750, 850 and 950 C specimens. The 1050 C exposure specimens showed the resolution of M{sub 23}C{sub 6} secondary carbides, and mechanical properties similar to the as-received solution annealed condition.

Jordan, C.E.; Rasefske, R.K.; Castagna, A. [Lockheed Martin Corp., Schenectady, NY (United States)

1999-03-01T23:59:59.000Z

391

Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida)  

E-Print Network (OSTI)

cultivars. Adaptation to high temperature stress is viewed as high priority in breeding programs of all major crops. High temperature stress negatively affects garden rose performance and the quality of flowers produced. The work described...

Greyvenstein, Ockert Frederick

2013-12-10T23:59:59.000Z

392

High temperature lined conduits, elbows and tees  

DOE Patents (OSTI)

A high temperature lined conduit comprising, a liner, a flexible insulating refractory blanket around and in contact with the liner, a pipe member around the blanket and spaced therefrom, and castable rigid refractory material between the pipe member and the blanket. Anchors are connected to the inside diameter of the pipe and extend into the castable material. The liner includes male and female slip joint ends for permitting thermal expansion of the liner with respect to the castable material and the pipe member. Elbows and tees of the lined conduit comprise an elbow liner wrapped with insulating refractory blanket material around which is disposed a spaced elbow pipe member with castable refractory material between the blanket material and the elbow pipe member. A reinforcing band is connected to the elbow liner at an intermediate location thereon from which extend a plurality of hollow tubes or pins which extend into the castable material to anchor the lined elbow and permit thermal expansion. A method of fabricating the high temperature lined conduit, elbows and tees is also disclosed which utilizes a polyethylene layer over the refractory blanket after it has been compressed to maintain the refractory blanket in a compressed condition until the castable material is in place. Hot gases are then directed through the interior of the liner for evaporating the polyethylene and setting the castable material which permits the compressed blanket to come into close contact with the castable material.

De Feo, Angelo (Passaic, NJ); Drewniany, Edward (Bergen, NJ)

1982-01-01T23:59:59.000Z

393

High temperature electrochemical corrosion rate probes  

SciTech Connect

Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

2005-09-01T23:59:59.000Z

394

High-Temperature, Air-Cooled Traction Drive Inverter Packaging...  

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

Temperature, Air-Cooled Traction Drive Inverter Packaging High-Temperature, Air-Cooled Traction Drive Inverter Packaging 2010 DOE Vehicle Technologies and Hydrogen Programs Annual...

395

Magnetic Induction of dx2-y2 + idxy Order in High- Tc Superconductors  

Science Journals Connector (OSTI)

I propose that the phase transition in Bi2Sr2CaCu2O8 recently observed by Krishana et al. [Science 277, 83 (1997)] is the development of a small dxy superconducting order parameter phased by ?/2 with respect to the principal dx2-y2 one to produce a minimum energy gap ?. The violation of both parity and time-reversal symmetry allows the development of a magnetic moment, the key to explaining the experiment. The origin of this moment is a quantized boundary current of IB=2e?/h at zero temperature.

R. B. Laughlin

1998-06-08T23:59:59.000Z

396

Powder synthesis and consolidation of thallium based high temperature superconductors. Final technical report  

SciTech Connect

Objective is to provide research samples of the Tl-based powders prepared by Rockwell`s spray calciner. Target compositions were set at 1.1 Tl, 1 Ba, 1 Ca, 1.5 Cu and 1.1 Tl, 1.12 Ba, 1 Ca, 1.88 Cu. Three calciner runs were made. The Nomex bags were replaced with Gore-Tex bags. The system was operated continuously for 24 h, producing 1.7 kg HTSC powder. Problems with CO{sub 2}, Tl volatility during sintering, etc., are discussed.

Gay, R.L. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

1990-06-23T23:59:59.000Z

397

Advanced high temperature superconductor film-based process using RABiTS  

SciTech Connect

The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (Contractor), Managing contractor for Oak Ridge National Laboratory (ORNL) and Midwest Superconductivity, Inc. (MSI) and Westinghouse Science and Electric Company (WEC) was to develop the basis for a commercial process for the manufacturing of superconducting tape based on the RABiTS technology developed at ORNL. The chosen method for deposition of YBCO films on RABiTS was Metal Organic chemical Vapor Deposition (MOCVD).

Goyal, A.; Hawsey, R.A.; Hack, J.; Moon, D.

2000-01-01T23:59:59.000Z

398

Force Free Configurations of Vortices in High Temperature Superconductors near H_{c2}  

E-Print Network (OSTI)

We study force-free configurations of Abrikosov flux lines in the line-liquid and line-crystal limit, near the melting transition at H_m. We show that the condition for zero force configurations can be solved by appealing to the structure of chiral liquid crystalline phases.

Randall D. Kamien

1998-04-27T23:59:59.000Z

399

Measurement of the vortex depinning force in a high temperature superconductor .  

E-Print Network (OSTI)

??Introduction: Superconductivity is one of those subjects in physics that is as captivating theoretically as it is experimentally interesting. The dual driving force of commercial (more)

Whitehead, Andrew Patrick

2005-01-01T23:59:59.000Z

400

Stability of an Uncooled Segment of a High-Temperature Superconductor  

Science Journals Connector (OSTI)

If the level of a liquid cryogen inadvertently falls below the top of a magnet winding, it may expose a segment of the conductor. Depending on the length of the uncooled segment and on how the matrix resistivi...

Lawrence Dresner

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Investigation of the Interface Between a Normal Metal and High Temperature Superconductor  

Science Journals Connector (OSTI)

Data are presented on the contact resistance between YBCO and arc sprayed silver and copper. Contact resistivities of 3.4 10-7 ?cm2 (Ag on YBCO) and 6 10-3 ?cm2 (Cu on YBCO)) are obtained at 80K without annea...

S. P. Ashworth; C. Beduz; K. Harrison

1990-01-01T23:59:59.000Z

402

Thermogravimetric and Microgravimetric Studies of the Surface Properties of a High-temperature Superconductor  

Science Journals Connector (OSTI)

This paper presents possible applications of thermal analysis, sorptomatic and microgravimetric methods for the study of surface adsorption and porosity properties via the programmed thermodesorption of liquid fr...

P. Staszczuk; G. W. Ch?dzy?ski; D. Sternik

403

Recent advances in high-temperature superconductor wire fabrication and applications development  

SciTech Connect

In this paper, recent advances in fabrication of HTS wires are summarized, and detailed discussion is provided for developments in near- and intermediate-term applications. Near-term applications, using presently obtainable current densities, include: liquid-nitrogen depth sensors, cryostat current leads, and magnetic bearings. Intermediate-term applications, using current densities expected to be available in the near future include fault-current limiters and short transmission lines. 25 refs.

Hull, J.R.; Uherka, K.L.

1992-01-01T23:59:59.000Z

404

Recent advances in high-temperature superconductor wire fabrication and applications development  

SciTech Connect

In this paper, recent advances in fabrication of HTS wires are summarized, and detailed discussion is provided for developments in near- and intermediate-term applications. Near-term applications, using presently obtainable current densities, include: liquid-nitrogen depth sensors, cryostat current leads, and magnetic bearings. Intermediate-term applications, using current densities expected to be available in the near future include fault-current limiters and short transmission lines. 25 refs.

Hull, J.R.; Uherka, K.L.

1992-08-01T23:59:59.000Z

405

Small-scale analog applications of high-transition-temperature superconductors  

Science Journals Connector (OSTI)

... . SQUID, L = 0.2 nH and /0 = 20 jjiA, and with wrf/27r = 20 MHz, at 77 K we find e " 10~28 J ...

John Clarke

1988-05-05T23:59:59.000Z

406

X-ray diffuse scattering studies of the local structural inhomogeneities in high temperature superconductors  

E-Print Network (OSTI)

profound and fundamental in?u- ence on electronic propertieselectronic structures signi?cantly and may have profound and fundamental

Liu, Xuerong

2009-01-01T23:59:59.000Z

407

Superconductor cable  

DOE Patents (OSTI)

A superconductor cable includes a superconductive cable core (1) and a cryostat (2) enclosing the same. The cable core (1) has a superconductive conductor (3), an insulation (4) surrounding the same and a shielding (5) surrounding the insulation (4). A layer (3b) of a dielectric or semiconducting material is applied to a central element (3a) formed from a normally conducting material as a strand or tube and a layer (3c) of at least one wire or strip of superconductive material is placed helically on top. The central element (3a) and the layer (3c) are connected to each other in an electrically conducting manner at the ends of the cable core (1).

Allais, Arnaud (Hannover, DE); Schmidt, Frank (Langenhagen, DE

2009-12-15T23:59:59.000Z

408

Method of fabricating a (1223) Tl-Ba-Ca-Cu-O superconductor  

DOE Patents (OSTI)

A method is disclosed for fabricating a polycrystalline <223> thallium-containing superconductor having high critical current at elevated temperatures and in the presence of a magnetic field. A powder precursor containing compounds other than thallium is compressed on a substrate. Thallium is incorporated in the densified powder precursor at a high temperature in the presence of a partial pressure of a thallium-containing vapor. 2 figs.

Tkaczyk, J.E.; Lay, K.W.; He, Q.

1997-07-08T23:59:59.000Z

409

The New England High-Resolution Temperature Program  

Science Journals Connector (OSTI)

The New England High-Resolution Temperature Program seeks to improve the accuracy of summertime 2-m temperature and dewpoint temperature forecasts in the New England region through a collaborative effort between the research and operational ...

David J. Stensrud; Nusrat Yussouf; Michael E. Baldwin; Jeffery T. McQueen; Jun Du; Binbin Zhou; Brad Ferrier; Geoffrey Manikin; F. Martin Ralph; James M. Wilczak; Allen B. White; Irina Djlalova; Jian-Wen Bao; Robert J. Zamora; Stanley G. Benjamin; Patricia A. Miller; Tracy Lorraine Smith; Tanya Smirnova; Michael F. Barth

2006-04-01T23:59:59.000Z

410

High Temperature Materials Laboratory (HTML) - PSD Directorate  

NLE Websites -- All DOE Office Websites (Extended Search)

filler A National Resource for Collaborative Materials Research The High Temperature Materials Laboratory (HTML) User Program is on hiatus due to federal budget reductions. However, research projects at the HTML still may be conducted on a cost-recovery basis through the Work for Others (WFO) Program or under a Cooperative R&D Agreement (CRADA). Dr. Edgar Lara-Curzio, HTML Director Tel: 865.574.1749 Fax: 865.574.4913 laracurzioe@ornl.gov Christine Goudy, Administrative Specialist Tel: 865.574.8295 Fax: 865.574.4913 goudyc@ornl.gov Oak Ridge National Laboratory [MST Home] [ORNL Home] [Site Index] [Search][Disclaimer] [Webmaster] Oak Ridge National Laboratory is a national multi-program research and development facility managed by UT-Battelle, LLC for the U.S. Department of Energy

411

Multilayer ultra-high-temperature ceramic coatings  

DOE Patents (OSTI)

A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

Loehman, Ronald E. (Albuquerque, NM); Corral, Erica L. (Tucson, AZ)

2012-03-20T23:59:59.000Z

412

Turbine vane with high temperature capable skins  

DOE Patents (OSTI)

A turbine vane assembly includes an airfoil extending between an inner shroud and an outer shroud. The airfoil can include a substructure having an outer peripheral surface. At least a portion of the outer peripheral surface is covered by an external skin. The external skin can be made of a high temperature capable material, such as oxide dispersion strengthened alloys, intermetallic alloys, ceramic matrix composites or refractory alloys. The external skin can be formed, and the airfoil can be subsequently bi-cast around or onto the skin. The skin and the substructure can be attached by a plurality of attachment members extending between the skin and the substructure. The skin can be spaced from the outer peripheral surface of the substructure such that a cavity is formed therebetween. Coolant can be supplied to the cavity. Skins can also be applied to the gas path faces of the inner and outer shrouds.

Morrison, Jay A. (Oviedo, FL)

2012-07-10T23:59:59.000Z

413

High temperature low friction surface coating  

DOE Patents (OSTI)

A high temperature, low friction, flexible coating for metal surfaces which are subject to rubbing contact includes a mixture of three parts graphite and one part cadmium oxide, ball milled in water for four hours, then mixed with thirty percent by weight of sodium silicate in water solution and a few drops of wetting agent. The mixture is sprayed 12-15 microns thick onto an electro-etched metal surface and air dried for thirty minutes, then baked for two hours at 65.degree. C. to remove the water and wetting agent, and baked for an additional eight hours at about 150.degree. C. to produce the optimum bond with the metal surface. The coating is afterwards burnished to a thickness of about 7-10 microns.

Bhushan, Bharat (Watervliet, NY)

1980-01-01T23:59:59.000Z

414

Ternary superconductor NbTiTa'' for high field superfluid magnets  

SciTech Connect

The possibility exists to obtain a higher Hc{sub 2}' upper critical field in the NbTi system which is normally limited by a spin-orbit coupling term. The introduction of scattering reduces this coupling. The spin-orbit scattering rate is proportional to Z{sup 4} and therefore leads logically to the introduction of a high atomic number element which is more or less similar with respect to all of the other properties, i.e., Tc. Previous studies have shown Tantalum to be an excellent choice. The present work represents an attempt to obtain a high current density, high field ternary magnet conductor (Jc (10T, 2K, {rho}eff = 10{sup {minus}12} {Omega}-cm)) > 2000A/mm{sup 2}. This goal was met, but the conductor was clearly not optimized.

McInturff, A.D.; Carson, J. (Fermi National Accelerator Lab., Batavia, IL (USA)); Larbalestier, D.; Lee, P.; McKinnel, J. (Wisconsin Univ., Madison, WI (USA)); Kanithi, H. (IGC/Advanced Superconductors, Inc., Waterbury, CT (USA)); McDonald, W.; O'Larey, P. (Teledyne-Wah Chang, Albany, OR (USA))

1990-06-01T23:59:59.000Z

415

Assessment of microelectronics packaging for high temperature, high reliability applications  

SciTech Connect

This report details characterization and development activities in electronic packaging for high temperature applications. This project was conducted through a Department of Energy sponsored Cooperative Research and Development Agreement between Sandia National Laboratories and General Motors. Even though the target application of this collaborative effort is an automotive electronic throttle control system which would be located in the engine compartment, results of this work are directly applicable to Sandia`s national security mission. The component count associated with the throttle control dictates the use of high density packaging not offered by conventional surface mount. An enabling packaging technology was selected and thermal models defined which characterized the thermal and mechanical response of the throttle control module. These models were used to optimize thick film multichip module design, characterize the thermal signatures of the electronic components inside the module, and to determine the temperature field and resulting thermal stresses under conditions that may be encountered during the operational life of the throttle control module. Because the need to use unpackaged devices limits the level of testing that can be performed either at the wafer level or as individual dice, an approach to assure a high level of reliability of the unpackaged components was formulated. Component assembly and interconnect technologies were also evaluated and characterized for high temperature applications. Electrical, mechanical and chemical characterizations of enabling die and component attach technologies were performed. Additionally, studies were conducted to assess the performance and reliability of gold and aluminum wire bonding to thick film conductor inks. Kinetic models were developed and validated to estimate wire bond reliability.

Uribe, F.

1997-04-01T23:59:59.000Z

416

Method of producing highly oxidized superconductors containing barium, copper, and a third metal  

DOE Patents (OSTI)

Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

Morris, D.E.

1996-02-20T23:59:59.000Z

417

E-Print Network 3.0 - appearance temperature field Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

<< < 1 2 3 4 5 > >> Page: << < 1 2 3 4 5 > >> 21 Polar Kerr-Effect Measurements of the High-Temperature YBa2Cu3O6x Superconductor: Evidence for Broken Symmetry near the...

418

High Temperature Integrated Thermoelectric Ststem and Materials  

SciTech Connect

The final goal of this project is to produce, by the end of Phase II, an all ceramic high temperature thermoelectric module. Such a module design integrates oxide ceramic n-type, oxide ceramic p-type materials as thermoelectric legs and oxide ceramic conductive material as metalizing connection between n-type and p-type legs. The benefits of this all ceramic module are that it can function at higher temperatures (> 700 C), it is mechanically and functionally more reliable and it can be scaled up to production at lower cost. With this all ceramic module, millions of dollars in savings or in new opportunities recovering waste heat from high temperature processes could be made available. A very attractive application will be to convert exhaust heat from a vehicle to reusable electric energy by a thermoelectric generator (TEG). Phase I activities were focused on evaluating potential n-type and p-type oxide compositions as the thermoelectric legs. More than 40 oxide ceramic powder compositions were made and studied in the laboratory. The compositions were divided into 6 groups representing different material systems. Basic ceramic properties and thermoelectric properties of discs sintered from these powders were measured. Powders with different particles sizes were made to evaluate the effects of particle size reduction on thermoelectric properties. Several powders were submitted to a leading thermoelectric company for complete thermoelectric evaluation. Initial evaluation showed that when samples were sintered by conventional method, they had reasonable values of Seebeck coefficient but very low values of electrical conductivity. Therefore, their power factors (PF) and figure of merits (ZT) were too low to be useful for high temperature thermoelectric applications. An unconventional sintering method, Spark Plasma Sintering (SPS) was determined to produce better thermoelectric properties. Particle size reduction of powders also was found to have some positive benefits. Two composition systems, specifically 1.0 SrO - 0.8 x 1.03 TiO2 - 0.2 x 1.03 NbO2.5 and 0.97 TiO2 - 0.03 NbO2.5, have been identified as good base line compositions for n-type thermoelectric compositions in future module design. Tests of these materials at an outside company were promising using that company's processing and material expertise. There was no unique p-type thermoelectric compositions identified in phase I work other than several current cobaltite materials. Ca3Co4O9 will be the primary p-type material for the future module design until alternative materials are developed. BaTiO3 and rare earth titanate based dielectric compositions show both p-type and n-type behavior even though their electrical conductivities were very low. Further research and development of these materials for thermoelectric applications is planned in the future. A preliminary modeling and optimization of a thermoelectric generator (TEG) that uses the n-type 1.0 SrO - 1.03 x 0.8 TiO2 - 1.03 x 0.2 NbO2.5 was performed. Future work will combine development of ceramic powders and manufacturing expertise at TAM, development of SPS at TAM or a partner organization, and thermoelectric material/module testing, modeling, optimization, production at several partner organizations.

Mike S. H. Chu

2011-06-06T23:59:59.000Z

419

Abstract--Temperature, current density and magnetic field distributions in YBCO bulk superconductor during a pulsed-field  

E-Print Network (OSTI)

-- bulk YBaCuO, stored magnetic energy, thermal coupling, magnetization, modelling. I. INTRODUCTION HE as cryo-permanent magnets [1], [2]. To magnetize the HTS, pulsed field magnetization (PFM) process1 Abstract-- Temperature, current density and magnetic field distributions in YBCO bulk

Paris-Sud XI, Université de

420

High Temperature Oxidation Performance of Aluminide Coatings  

SciTech Connect

Aluminide coatings are of interest for many high temperature applications because of the possibility of improving the oxidation resistance of structural alloys by forming a protective external alumina scale. Steam and exhaust gas environments are of particular interest because alumina is less susceptible to the accelerated attack due to hydroxide formation observed for chromia- and silica-forming alloys and ceramics. For water vapor testing, one ferritic (Fe-9Cr-1Mo) and one austenitic alloy (304L) have been selected as substrate materials and CVD coatings have been used in order to have a well-controlled, high purity coating. It is anticipated that similar aluminide coatings could be made by a higher-volume, commercial process such as pack cementation. Previous work on this program has examined as-deposited coatings made by high and low Al activity CVD processes and the short-term performance of these coatings. The current work is focusing on the long term behavior in both diffusion tests16 and oxidation tests of the thicker, high Al activity coatings. For long-term coating durability, one area of concern has been the coefficient of thermal expansion (CTE) mismatch between coating and substrate. This difference could cause cracking or deformation that could reduce coating life. Corrosion testing using thermal cycling is of particular interest because of this potential problem and results are presented where a short exposure cycle (1h) severely degraded aluminide coatings on both types of substrates. To further study the potential role of aluminide coatings in fossil energy applications, several high creep strength Ni-base alloys were coated by CVD for testing in a high pressure (20atm) steam-CO{sub 2} environment for the ZEST (zero-emission steam turbine) program. Such alloys would be needed as structural and turbine materials in this concept. For Ni-base alloys, CVD produces a {approx}50{mu}m {beta}-NiAl outer layer with an underlying interdiffusion zone. Specimens of HR160, alloy 601 and alloy 230 were tested with and without coatings at 900 C and preliminary post-test characterization is reported.

Pint, Bruce A [ORNL; Zhang, Ying [Tennessee Technological University; Haynes, James A [ORNL; Wright, Ian G [ORNL

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

9 High Temperature 9 High Temperature Membrane Working Group Meeting Archives to someone by E-mail Share Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on Facebook Tweet about Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on Twitter Bookmark Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on Google Bookmark Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on Delicious Rank Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on Digg Find More places to share Fuel Cell Technologies Office: 2009 High Temperature Membrane Working Group Meeting Archives on AddThis.com...

422

High-Temperature Solar Selective Coating Development for Power...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q2 High-Temperature Solar Selective Coating Development for Power Tower Receivers - FY13 Q2...

423

Development of a 100-Watt High Temperature Thermoelectric Generator  

Energy.gov (U.S. Department of Energy (DOE))

Test results for low and high temperature thermoelectric generators (TEG) those for a 530-watt BiTe TEG; design and construction of a 100-watt high temperature TEG currently in fabrication.

424

Mold, flow, and economic considerations in high temperature precision casting  

E-Print Network (OSTI)

Casting high temperature alloys that solidify through a noticeable two phase region, specifically platinum-ruthenium alloys, is a particularly challenging task due to their high melting temperature and this necessitates ...

Humbert, Matthew S

2013-01-01T23:59:59.000Z

425

Corrosion Studies in High-Temperature Molten Salt Systems for...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Corrosion Studies in High-Temperature Molten Salt Systems for CSP Applications - FY13 Q1 Corrosion Studies in High-Temperature Molten Salt Systems for CSP Applications - FY13 Q1...

426

High and Low Temperature Series Estimates for the Critical Temperature of the 3D Ising Model  

E-Print Network (OSTI)

High and Low Temperature Series Estimates for the Critical Temperature of the 3D Ising Model Zaher Abstract We have analysed low and high temperature series expansions for the three­dimensional Ising model temperature of the three­dimensional (3d) Ising model on the simple cubic lattice has been exhaustively

Adler, Joan

427

Optical excitation of quasiparticle pairs in the vortex core of high- T sub c superconductors  

SciTech Connect

A far-infrared resonance has been observed in superconducting YBa{sub 2}Cu{sub 3}O{sub 7} thin films in the presence of high magnetic fields. It corresponds to the quasiparticle pair creation process inside the vortex core. The resonance frequency is {omega}{sub 0}=1.3{ital kT}{sub {ital c}}/{h bar} with a linewidth 1/{tau}{congruent}0.6{omega}. This value for {omega}{sub 0} implies, within BCS theory, a large energy gap in YBa{sub 2}Cu{sub 3}O{sub 7}.

Karraie, K.; Choi, E.J.; Dunmore, F.; Liu, S.H.; Drew, H.D. (Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States) Laboratory for Physical Sciences, College Park, Maryland 20740 (United States)); Li, Q.; Fenner, D.B. (Advanced Fuel Research, E. Hartford, Connecticut 06138 (United States)); Zhu, Y.D.; Zhang, F. (Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States))

1992-07-06T23:59:59.000Z

428

Hydrogen Production from Nuclear Energy via High Temperature Electrolysis  

SciTech Connect

This paper presents the technical case for high-temperature nuclear hydrogen production. A general thermodynamic analysis of hydrogen production based on high-temperature thermal water splitting processes is presented. Specific details of hydrogen production based on high-temperature electrolysis are also provided, including results of recent experiments performed at the Idaho National Laboratory. Based on these results, high-temperature electrolysis appears to be a promising technology for efficient large-scale hydrogen production.

James E. O'Brien; Carl M. Stoots; J. Stephen Herring; Grant L. Hawkes

2006-04-01T23:59:59.000Z

429

Agenda for the High Temperature Membrane Working Group Meeting  

Energy.gov (U.S. Department of Energy (DOE))

This agenda provides information about the Agenda for the High Temperature Membrane Working Group Meeting on September 14, 2006.

430

High Temperature Membrane Working Group Meeting, May 14, 2007  

Energy.gov (U.S. Department of Energy (DOE))

This agenda provides information about the High Temperature Membrane Working Group Meeting on May 14, 2007 in Arlington, Va.

431

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

More Documents & Publications Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Vehicle Technologies Office...

432

Some improved geometrics for Josephson-junction investigations of the order-parameter symmetry in high-T{sub c} superconductors.  

SciTech Connect

We propose two new geometries for Josephson junction experiments between the edge of an orthorhombic, untwinned single-crystal high-{Tc} superconductor, assumed to have an order parameter of the mixed s{+-}d{sub x}2-{sub y}2 variety, and a conventional, s-wave superconductor. The first geometry is a straight-edge Josephson junction cut at an angle {phi}{sup 0} with respect to the a-axis edge of a high-{Tc} crystal. We studied the effects of a regular array of a/b steps comprising the edge upon the I{sub c}(B) pattern for different {phi}{sup 0} values. Varying {phi}{sup 0} can elucidate the locations of any purported order-parameter nodes. The second geometry is a disk cut from a high-{Tc} single crystal, with a Josephson junction formed on the edge, centered at {phi}{sup 0}, with an angular width of {Delta}{phi}. The case {Delta}{phi}={pi} is nearly free of systematic flux trapping problems, and is shown to be particularly important in quantifying the precise amount of s/d order-parameter mixing. Smaller {Delta}{phi} values can also be useful in locating the purported order-parameter nodes.

Klemm, R. A.; Materials Science Division

1997-02-01T23:59:59.000Z

433

Some improved geometries for Josephson-junction investigations of the order-parameter symmetry in high-T{sub c} superconductors  

SciTech Connect

We propose two new geometries for Josephson junction experiments between the edge of an orthorhombic, untwinned single-crystal high-T{sub c} superconductor, assumed to have an order parameter of the mixed s{plus_minus}d{sub x{sup 2}{minus}y{sup 2}} variety, and a conventional, s-wave superconductor. The first geometry is a straight-edge Josephson junction cut at an angle {phi}{sub 0} with respect to the a-axis edge of a high-T{sub c} crystal. We studied the effects of a regular array of a/b steps comprising the edge upon the I{sub c}(B) pattern for different {phi}{sub 0} values. Varying {phi}{sub 0} can elucidate the locations of any purported order-parameter nodes. The second geometry is a disk cut from a high-T{sub c} single crystal, with a Josephson junction formed on the edge, centered at {phi}{sub 0}, with an angular width of {Delta}{phi}. The case {Delta}{phi}={pi} is nearly free of systematic flux trapping problems, and is shown to be particularly important in quantifying the precise amount of s/d order-parameter mixing. Smaller {Delta}{phi} values can also be useful in locating the purported order-parameter nodes. {copyright} {ital 1997} {ital The American Physical Society}

Klemm, R.A. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

1997-02-01T23:59:59.000Z

434

High performance internal reforming unit for high temperature fuel cells  

DOE Patents (OSTI)

A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

Ma, Zhiwen (Sandy Hook, CT); Venkataraman, Ramakrishnan (New Milford, CT); Novacco, Lawrence J. (Brookfield, CT)

2008-10-07T23:59:59.000Z

435

Project Profile: High-Temperature Solar Selective Coating Development...  

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

water droplets falling on a flat, dust-covered surface. The research team is exploring materials with high melting temperatures, intrinsic oxidation resistance, high thermal...

436

Free energy of QCD at high temperature  

Science Journals Connector (OSTI)

Effective-field-theory methods are used to separate the free energy for a non-Abelian gauge theory at high temperature T into the contributions from the momentum scales T, gT, and g2T, where g is the coupling constant at the scale 2?T. The effects of the scale T enter through the coefficients in the effective Lagrangian for the three-dimensional effective theory obtained by dimensional reduction. These coefficients can be calculated as power series in g2. The contribution to the free energy from the scale gT can be calculated using perturbative methods in the effective theory. It can be expressed as an expansion in g starting at order g3. The contribution from the scale g2T must be calculated using nonperturbative methods, but nevertheless it can be expanded in powers of g beginning at order g6. We calculate the free energy explicitly to order g5. We also outline the calculations necessary to obtain the free energy to order g6.

Eric Braaten and Agustin Nieto

1996-03-15T23:59:59.000Z

437

High Temperature 300C Directional Drilling System  

Energy.gov (U.S. Department of Energy (DOE))

Project objective: provide a directional drilling system that can be used at environmental temperatures of up to 300C; and at depths of 10; 000 meters.

438

High temperature, optically transparent plastics from biomass  

NLE Websites -- All DOE Office Websites (Extended Search)

temperature, optically transparent plastics from biomass At a Glance Rapid, selective catalytic system to produce vinyl plastics from renewable biomass Stereoregular...

439

Stable large-scale solver for Ginzburg-Landau equations for superconductors  

E-Print Network (OSTI)

Understanding the interaction of vortices with inclusions in type-II superconductors is a major outstanding challenge both for fundamental science and energy applications. At application-relevant scales, the long-range interactions between a dense configuration of vortices and the dependence of their behavior on external parameters, such as temperature and an applied magnetic field, are all important to the net response of the superconductor. Capturing these features, in general, precludes analytical description of vortex dynamics and has also made numerical simulation prohibitively expensive. Here we report on a highly optimized iterative implicit solver for the time-dependent Ginzburg-Landau equations suitable for investigations of type-II superconductors on massively parallel architectures. Its main purpose is to study vortex dynamics in disordered or geometrically confined mesoscopic systems. In this work, we present the discretization and time integration scheme in detail for two types of boundary condit...

Sadovskyy, I A; Phillips, C L; Karpeev, D A; Glatz, A

2014-01-01T23:59:59.000Z

440

NOvel Refractory Materials for High Alkali, High Temperature Environments  

SciTech Connect

Refractory materials can be limited in their application by many factors including chemical reactions between the service environment and the refractory material, mechanical degradation of the refractory material by the service environment, temperature limitations on the use of a particular refractory material, and the inability to install or repair the refractory material in a cost effective manner or while the vessel was in service. The objective of this project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al2O3 spinel or other similar magnesia/alumina containing unshaped refractory composition (castables, gunnables, shotcretes, etc) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, highalkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. A research team was formed to carry out the proposed work led by Oak Ridge National Laboratory (ORNL) and was comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The two goals of this project were to produce novel refractory compositions which will allow for improved energy efficiency and to develop new refractory application techniques which would improve the speed of installation. Also methods of hot installation were sought which would allow for hot repairs and on-line maintenance leading to reduced process downtimes and eliminating the need to cool and reheat process vessels.

Hemrick, J.G.; Griffin, R. (MINTEQ International, Inc.)

2011-08-30T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Ultra-High Temperature Distributed Wireless Sensors  

SciTech Connect

Research was conducted towards the development of a passive wireless sensor for measurement of temperature in coal gasifiers and coal-fired boiler plants. Approaches investigated included metamaterial sensors based on guided mode resonance filters, and temperature-sensitive antennas that modulate the frequency of incident radio waves as they are re-radiated by the antenna. In the guided mode resonant filter metamaterial approach, temperature is encoded as changes in the sharpness of the filter response, which changes with temperature because the dielectric loss of the guided mode resonance filter is temperature-dependent. In the mechanically modulated antenna approach, the resonant frequency of a vibrating cantilever beam attached to the antenna changes with temperature. The vibration of the beam perturbs the electrical impedance of the antenna, so that incident radio waves are phase modulated at a frequency equal to the resonant frequency of the vibrating beam. Since the beam resonant frequency depends on temperature, a Doppler radar can be used to remotely measure the temperature of the antenna. Laboratory testing of the guided mode resonance filter failed to produce the spectral response predicted by simulations. It was concluded that the spectral response was dominated by spectral reflections of radio waves incident on the filter. Laboratory testing of the mechanically modulated antenna demonstrated that the device frequency shifted incident radio waves, and that the frequency of the re-radiated waves varied linearly with temperature. Radio wave propagation tests in the convection pass of a small research boiler plant identified a spectral window between 10 and 13 GHz for low loss propagation of radio waves in the interior of the boiler.

May, Russell; Rumpf, Raymond; Coggin, John; Davis, Williams; Yang, Taeyoung; O'Donnell, Alan; Bresnahan, Peter

2013-03-31T23:59:59.000Z

442

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS  

E-Print Network (OSTI)

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS Accelerometers Z. Szcs, G. Nagy|nagyg|hodossy|rencz|poppe>@eet.bme.hu Abstract - In this paper vibration combined high temperature cycle tests for packaged capacitive SOI- MEMS designed and realized at BME ­ DED. Twenty thermal cycles of combined Temperature Cycle Test and Fatigue

Boyer, Edmond

443

High temperature, minimally invasive optical sensing modules  

DOE Patents (OSTI)

A remote temperature sensing system includes a light source selectively producing light at two different wavelengths and a sensor device having an optical path length that varies as a function of temperature. The sensor receives light emitted by the light source and redirects the light along the optical path length. The system also includes a detector receiving redirected light from the sensor device and generating respective signals indicative of respective intensities of received redirected light corresponding to respective wavelengths of light emitted by the light source. The system also includes a processor processing the signals generated by the detector to calculate a temperature of the device.

Riza, Nabeel Agha (Oviedo, FL); Perez, Frank (Tujunga, CA)

2008-02-05T23:59:59.000Z

444

Highly temperature insensitive quantum cascade lasers  

SciTech Connect

An InP based quantum cascade laser (QCL) heterostructure emitting around 5 {mu}m is grown with gas-source molecular beam epitaxy. The QCL core design takes a shallow-well approach to maximize the characteristic temperatures, T{sub 0} and T{sub 1}, for operations above room temperature. A T{sub 0} value of 383 K and a T{sub 1} value of 645 K are obtained within a temperature range of 298-373 K. In room temperature continuous wave operation, this design gives a single facet output power of 3 W and a wall plug efficiency of 16% from a device with a cavity length of 5 mm and a ridge width of 8 {mu}m.

Bai, Y.; Bandyopadhyay, N.; Tsao, S.; Selcuk, E.; Slivken, S.; Razeghi, M. [Department of Electrical Engineering and Computer Science, Center for Quantum Devices, Northwestern University, Evanston, Illinois 60208 (United States)

2010-12-20T23:59:59.000Z

445

SciTech Connect: Enhanced Superconducting Gaps in Trilayer High...  

NLE Websites -- All DOE Office Websites (Extended Search)

Enhanced Superconducting Gaps in Trilayer High-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor Citation Details In-Document Search Title: Enhanced...

446

Fuel Cell Technologies Office: High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

High Temperature Membrane Working Group High Temperature Membrane Working Group The High Temperature Membrane Working Group consists of government, industry, and university researchers interested in developing high temperature membranes for fuel cells. Description Technical Targets Meetings Contacts Description Polymer electrolyte membrane (PEM) fuel cells typically operate at temperatures no higher than 60°C-80°C due to structural limitations of the membrane. Operating PEM fuel cell stacks at higher temperatures (120°C for transportation and 150°C for stationary applications), however, would yield significant energy benefits. For example, heat rejection is easier at higher temperatures, which would allow use of smaller heat exchangers in fuel cell power systems. In addition, for reformate fuel cell systems, carbon monoxide (CO) tolerance of the stack is less problematic at higher temperatures, which would reduce the size requirements or possibly eliminate the need for some CO clean-up beds in the fuel processor.

447

High-temperature neutron diffraction study of deuterated brucite  

Science Journals Connector (OSTI)

To study the structural behavior of brucite at high temperature, we conducted in situ neutron diffraction experiments of a deuterated brucite powder sample, Mg(OD)2, in the temperature range 313583K. The sample...

Hongwu Xu; Yusheng Zhao; Donald D. Hickmott

2013-11-01T23:59:59.000Z

448

Cryogenic deformation of high temperature superconductive composite structures  

DOE Patents (OSTI)

An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Roberts, Peter R. (Groton, MA); Michels, William (Brookline, MA); Bingert, John F. (Jemez Springs, NM)

2001-01-01T23:59:59.000Z

449

Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

About About Printable Version Share this resource Send a link to Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives to someone by E-mail Share Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives on Facebook Tweet about Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives on Twitter Bookmark Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives on Google Bookmark Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives on Delicious Rank Fuel Cell Technologies Office: 2005 High Temperature Membrane Working Group Meeting Archives on Digg Find More places to share Fuel Cell Technologies Office: 2005 High

450

Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

About About Printable Version Share this resource Send a link to Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives to someone by E-mail Share Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives on Facebook Tweet about Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives on Twitter Bookmark Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives on Google Bookmark Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives on Delicious Rank Fuel Cell Technologies Office: 2004 High Temperature Membrane Working Group Meeting Archives on Digg Find More places to share Fuel Cell Technologies Office: 2004 High

451

Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

About About Printable Version Share this resource Send a link to Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives to someone by E-mail Share Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives on Facebook Tweet about Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives on Twitter Bookmark Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives on Google Bookmark Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives on Delicious Rank Fuel Cell Technologies Office: 2010 High Temperature Membrane Working Group Meeting Archives on Digg Find More places to share Fuel Cell Technologies Office: 2010 High

452

Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group  

NLE Websites -- All DOE Office Websites (Extended Search)

About About Printable Version Share this resource Send a link to Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives to someone by E-mail Share Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives on Facebook Tweet about Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives on Twitter Bookmark Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives on Google Bookmark Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives on Delicious Rank Fuel Cell Technologies Office: 2007 High Temperature Membrane Working Group Meeting Archives on Digg Find More places to share Fuel Cell Technologies Office: 2007 High

453

Preparation of superconductor precursor powders  

DOE Patents (OSTI)

A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

Bhattacharya, Raghunath (Littleton, CO); Blaugher, Richard D. (Evergreen, CO)

1995-01-01T23:59:59.000Z

454

Viscosity of high-temperature iodine  

Science Journals Connector (OSTI)

The viscosity coefficient of iodine in the temperature range 500?T?3000 K is calculated. Because of the low dissociation energy of the I2 molecules, the dissociation degree of the gas increases quickly with temperature, and I+I2 and I+I collisions must be taken into account in calculations of viscosity at temperatures greater than 1000. Several possible channels for atom-atom interaction are considered, and the resulting collision integrals are averaged over all the important channels. It is also shown that the rigid-sphere model is inaccurate in predictions of the viscosity. The approach of the present work is general and can be used for other diatomic gases with arbitrary dissociation degree.

Steve H. Kang and Joseph A. Kunc

1991-09-15T23:59:59.000Z

455

High-temperature for improved ES  

E-Print Network (OSTI)

standard requires tests both for u powered systems. For the latter testin temperature has to be taken a perfect electric insulation active device. Regarding ESD r proposed protection should provide current: We propose a new MOS-IGB robustness ESD protection with low temp diffusions in the drain with various

Paris-Sud XI, Université de

456

High Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells  

Energy.gov (U.S. Department of Energy (DOE))

DOE Geothermal Peer Review 2010 - Presentation. Project objectives: Design, demonstrate, and qualify high-temperature high pressure zonal isolation devices compatible with the high temperature downhole Enhanced Geothermal Systems (EGS) environment.

457

Computational and Experimental Development of Novel High-Temperature Alloys  

NLE Websites -- All DOE Office Websites (Extended Search)

Development of Novel High-Temperature Alloys Background The need for fossil-fueled power plants to run cleaner and more efficiently leads toward ever-higher operating temperatures and pressures. Gas turbines, which can be fueled by natural gas, synthetic gas (syngas), or a high-hydrogen stream derived from coal, are critical components in this development. High-temperature operation of turbines is generally achieved by using nickel-chrome superalloys with coatings

458

First high-temperature electronics products survey 2005.  

SciTech Connect

On April 4-5, 2005, a High-Temperature Electronics Products Workshop was held. This workshop engaged a number of governmental and private industry organizations sharing a common interest in the development of commercially available, high-temperature electronics. One of the outcomes of this meeting was an agreement to conduct an industry survey of high-temperature applications. This report covers the basic results of this survey.

Normann, Randy Allen

2006-04-01T23:59:59.000Z

459

Rotational viscometer for high-pressure, high-temperature fluids  

DOE Patents (OSTI)

The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer include a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. Means are provided to generate an output indicative of the phase difference between the two waveforms. The viscometer is comparatively simple, inexpensive, rugged, and does not require shaft seals.

Carr, K.R.

1983-06-06T23:59:59.000Z

460

High pressure--high temperature research using high energy synchrotron radiation at the TRISTAN accumulation ring  

SciTech Connect

High energy synchrotron radiation emitted from the bending magnet of the TRISTAN accumulation ring (6.5 GeV) at the National Laboratory for High Energy Physics has been used for the high pressure--high temperature diffraction experiments using a multianvil press system, MAX80. Owing to the specific features of high energy synchroton radiation, significant improvements have been brought to the high pressure research. The wide energy range of diffraction spectrum leads to an increase in the number of observable diffraction peaks in an energy-dispersive method, resulting in an increase in the accuracy of the measurements of the lattice and thermal parameters. Due to the high penetrating power of radiation, diffraction patterns can be taken in a short time from materials containing heavy elements or materials surrounded by a metal foil. Typical examples of high pressure--high temperature experiments with high energy synchrotron radiation are also described.

Kikegawa, T.; Shimomura, O.; Iwasaki, H.; Sato, S.; Mikuni, A.; Iida, A.; Kamiya, N.

1989-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

ANALYSIS OF A HIGH TEMPERATURE GAS-COOLED REACTOR POWERED HIGH TEMPERATURE ELECTROLYSIS HYDROGEN PLANT  

SciTech Connect

An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322C and 750C, respectively. The reactor heat is used to produce heat and electric power to the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

M. G. McKellar; E. A. Harvego; A. M. Gandrik

2010-11-01T23:59:59.000Z

462

Overview of Fraunhofer IPM Activities in High Temperature Bulk...  

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

Workshop including an overview about Fraunhofer IPM, new funding situation in Germany, high temperature material and modules, energy-autarkic sensors, and thermoelectric...

463

Development of a 500 Watt High Temperature Thermoelectric Generator...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

More Documents & Publications Development of a 100-Watt High Temperature Thermoelectric Generator Automotive Waste Heat Conversion to Power Program Automotive Waste Heat...

464

Institute of Chemical Engineering and High Temperature Chemical...  

Open Energy Info (EERE)

Chemical Processes ICEHT Jump to: navigation, search Name: Institute of Chemical Engineering and High Temperature Chemical Processes (ICEHT) Place: Hellas, Greece Zip:...

465

Evaluation of High-Temperature Alloys for Helium Gas Turbines  

Science Journals Connector (OSTI)

C. 1. Mechanical Property / Status of Metallic Materials Development for Application in Advanced High-Temperature Gas-Cooled Reactor / Material

Wolfgang Jakobeit; Jrn-Peter Pfeifer; Georg Ullrich

466

Variable Temperature Ultra-High Vacuum Scanning Tunneling Microscope...  

NLE Websites -- All DOE Office Websites (Extended Search)

Vacuum Scanning Tunneling Microscope The Omicron variable temperature ultra-high vacuum (UHV) scanning tunneling microscope (VTSTM) is designed to study the structure of both clean...

467

Fundamental Corrosion Studies in High-Temperature Molten Salt...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Studies in High-Temperature Molten Salt Systems for CSP Applications Savannah River National Laboratory April 15, 2013 | Garcia-Diaz * The overall project approach will combine...

468

Corrosion Studies in High-Temperature Molten Salt Systems for...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Studies in High-Temperature Molten Salt Systems for CSP Applications Savannah River National Laboratory Garcia-Diaz A 1152013:Garcia-Diaz * The overall project approach will...

469

Solid oxide steam electrolysis for high temperature hydrogen production .  

E-Print Network (OSTI)

??This study has focused on solid oxide electrolyser cells for high temperature steam electrolysis. Solid oxide electrolysis is the reverse operation of solid oxide fuel (more)

Eccleston, Kelcey L.

2007-01-01T23:59:59.000Z

470

Detecting Fractures Using Technology at High Temperatures and...  

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

Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI); 2010 Geothermal Technology Program Peer Review Report Detecting...

471

Detecting Fractures Using Technology at High Temperatures and...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fractures Using Technology at High Temperatures and Depths - Geothermal Ultrasonic Fracture Imager (GUFI) Presentation Number: 015 Investigator: Patterson, Doug (Baker Hughes...

472

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Temperature Bulk Thermoelectric Energy Conversion for Efficient Waste Heat Recovery Project Overview 2 * Start: October 2011 * End: September 2015 * Percent complete -...

473

Feasibility and Design Studies for a High Temperature Downhole Tool  

Energy.gov (U.S. Department of Energy (DOE))

Project objective: Perform feasibility and design studies for a high temperature downhole tool; which uses nuclear techniques for characterization purposes; using measurements and modeling/simulation.

474

High-Temperature Aluminum Alloys | Department of Energy  

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

and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting pm044smith2012o.pdf More Documents & Publications High-Temperature Aluminum Alloys Vehicle...

475

High Temperature, High Voltage Fully Integrated Gate Driver Circuit  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

driver circuit, 5-V on- chip voltage regulator, short-circuit protection, undervoltage lockout, bootstrap capacitor, dead time controller and temperature sensor * 0.8-micron,...

476

High-Temperature Superconductivity Cable Demonstration Projects  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Temperature Temperature Superconductivity Cable Demonstration Projects Superconductivity Power Equipment www.oe.energy.gov Phone: 202-586-1411 Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585. Plugging America Into the Future of Power "A National Effort to Introduce New Technology into the Power Delivery Infrastructure" "In order to meet President Obama's ambitious energy goals, we must modernize the nation's electrical grid to improve the transmission, storage and reliability of clean energy across the country and help to move renewable energy from the places it can be produced to the places it can be used. The Department of Energy is working with industry partners to develop the

477

High Temperature Oxidation Resistance and Surface Electrical...  

NLE Websites -- All DOE Office Websites (Extended Search)

plates with oxidation resistant coatings. Candidate coatings must exhibit chemical and thermal-mechanical stability and high electrical conductivity during long-term...

478

High temperature elemental losses and mineralogical  

E-Print Network (OSTI)

future energy crops. Combustion in biomass fueled boilers,in ash during combustion of biomass fuels is important forC. Combustion characteristics of high alkali biomass. Final

Thy, P.; Jenkins, B. M.; Grundvig, S.; Shiraki, R.; Lesher, C. E.

2006-01-01T23:59:59.000Z

479

Advanced High-Temperature, High-Pressure Transport Reactor Gasification  

SciTech Connect

The U.S. Department of Energy (DOE) National Energy Technology Laboratory Office of Coal and Environmental Systems has as its mission to develop advanced gasification-based technologies for affordable, efficient, zero-emission power generation. These advanced power systems, which are expected to produce near-zero pollutants, are an integral part of DOE's Vision 21 Program. DOE has also been developing advanced gasification systems that lower the capital and operating costs of producing syngas for chemical production. A transport reactor has shown potential to be a low-cost syngas producer compared to other gasification systems since its high-throughput-per-unit cross-sectional area reduces capital costs. This work directly supports the Power Systems Development Facility utilizing the KBR transport reactor located at the Southern Company Services Wilsonville, Alabama, site. Over 2800 hours of operation on 11 different coals ranging from bituminous to lignite along with a petroleum coke has been completed to date in the pilot-scale transport reactor development unit (TRDU) at the Energy & Environmental Research Center (EERC). The EERC has established an extensive database on the operation of these various fuels in both air-blown and oxygen-blown modes utilizing a pilot-scale transport reactor gasifier. This database has been useful in determining the effectiveness of design changes on an advanced transport reactor gasifier and for determining the performance of various feedstocks in a transport reactor. The effects of different fuel types on both gasifier performance and the operation of the hot-gas filter system have been determined. It has been demonstrated that corrected fuel gas heating values ranging from 90 to 130 Btu/scf have been achieved in air-blown mode, while heating values up to 230 Btu/scf on a dry basis have been achieved in oxygen-blown mode. Carbon conversions up to 95% have also been obtained and are highly dependent on the oxygen-coal ratio. Higher-reactivity (low-rank) coals appear to perform better in a transport reactor than the less reactive bituminous coals. Factors that affect TRDU product gas quality appear to be coal type, temperature, and air/coal ratios. Testing with a higher-ash, high-moisture, low-rank coal from the Red Hills Mine of the Mississippi Lignite Mining Company has recently been completed. Testing with the lignite coal generated a fuel gas with acceptable heating value and a high carbon conversion, although some drying of the high-moisture lignite was required before coal-feeding problems were resolved. No ash deposition or bed material agglomeration issues were encountered with this fuel. In order to better understand the coal devolatilization and cracking chemistry occurring in the riser of the transport reactor, gas and solid sampling directly from the riser and the filter outlet has been accomplished. This was done using a baseline Powder River Basin subbituminous coal from the Peabody Energy North Antelope Rochelle Mine near Gillette, Wyoming.

Michael Swanson; Daniel Laudal

2008-03-31T23:59:59.000Z

480

Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells  

SciTech Connect

Hydrogen can be produced from water splitting with relatively high efficiency using high temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

James E. O'Brien

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "high temperature superconductors" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

High-Energy Spin Excitations in the Electron-Doped Superconductor Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} with T{sub c}=21 K  

SciTech Connect

We use high-resolution inelastic neutron scattering to study the low-temperature magnetic excitations of the electron-doping superconductor Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4-{delta}} (T{sub c}=21{+-}1 K) over a wide energy range (4 meV{<=}({Dirac_h}/2{pi}){omega}{<=}330 meV). The effect of electron doping is to cause a wave vector (Q) broadening in the low-energy (({Dirac_h}/2{pi}){omega}{<=}80 meV) commensurate spin fluctuations at (0.5, 0.5) and to suppress the intensity of spin-wave-like excitations at high energies (({Dirac_h}/2{pi}){omega}{>=}100 meV). This leads to a substantial redistribution in the spectrum of the local dynamical spin susceptibility {chi}{sup ''}({omega}), and reveals a new energy scale similar to that of the lightly hole-doped YB{sub 2}Cu{sub 3}O{sub 6.353} (T{sub c}=18 K)

Wilson, Stephen D.; Li Shiliang; Woo, Hyungje [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Dai, Pengcheng [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Mook, H.A. [Center for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Frost, C.D. [ISIS Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom); Komiya, Seiki; Ando, Yoichi [Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511 (Japan)

2006-04-21T23:59:59.000Z

482

Advancing the technology base for high-temperature membranes  

SciTech Connect

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project addresses the major issues confronting the implementation of high-temperature membranes for separations and catalysis. We are pursuing high-temperature membrane systems that can have a large impact for DOE and be industrially relevant. A major obstacle for increased use of membranes is that most applications require the membrane material to withstand temperatures above those acceptable for polymer-based systems. Advances made by this project have helped industry and DOE move toward high-temperature membrane applications to improve overall energy efficiency.

Dye, R.C.; Birdsell, S.A.; Snow, R.C. [and others

1997-10-01T23:59:59.000Z

483

Preparation and properties of amorphous MgB2/MgO superstructures: A new model disordered superconductor  

SciTech Connect

In this paper we introduce a novel method for fabricating MgB{sub 2}/MgO multilayers and demonstrate the potential for using them as a new model for disordered superconductors. In this approach we control the annealing of the MgB{sub 2} to yield an interesting new class of disordered (amorphous) superconductors with relatively high transition temperatures. The multilayers appear to exhibit quasi-two-dimensional superconductivity with controlled anisotropy. We discuss the properties of the multilayers as the thickness of the components of the bilayers vary.

Siemons, W.

2010-04-05T23:59:59.000Z

484

POWER-TO-GAS PROCESS WITH HIGH TEMPERATURE ELECTROLYSIS  

E-Print Network (OSTI)

POWER-TO-GAS PROCESS WITH HIGH TEMPERATURE ELECTROLYSIS AND CO2 METHANATION NOVEMBER 19th 2013 IRES. Energy background 2. Power-to-Substitute Natural Gas process with high temperature steam electrolysis Gas-to-heat Gas-to-mobility Gas-to-power Excess Production = Consumption Distribution and storing

Paris-Sud XI, Université de

485

High Temperature Evaluation of Tantalum Capacitors - Test 1  

DOE Data Explorer (OSTI)

Tantalum capacitors can provide much higher capacitance at high-temperatures than the ceramic capacitors. This study evaluates selected tantalum capacitors at high temperatures to determine their suitability for you in geothermal field. This data set contains results of the first test where three different types of capacitors were evaluated at 260C.

Grzegorz Cieslewski

486

High Temperature Evaluation of Tantalum Capacitors - Test 1  

SciTech Connect

Tantalum capacitors can provide much higher capacitance at high-temperatures than the ceramic capacitors. This study evaluates selected tantalum capacitors at high temperatures to determine their suitability for you in geothermal field. This data set contains results of the first test where three different types of capacitors were evaluated at 260C.

Cieslewski, Grzegorz

2014-09-28T23:59:59.000Z

487

Gas Viscosity at High Pressure and High Temperature  

E-Print Network (OSTI)

. Although viscosity of some pure components such as methane, ethane, propane, butane, nitrogen, carbon dioxide and binary mixtures of these components at low-intermediate pressure and temperature had been studied intensively and been understood thoroughly...

Ling, Kegang

2012-02-14T23:59:59.000Z

488

A Study of a High-Tc Superconducting Fault Current Limiter (No. 2): Development of an Element for 100-V Class Power Systems  

Science Journals Connector (OSTI)

The application of a high critical temperature (Tc) superconductor with a high critical current density (Jc) to a fault current limiter (FCL) was investigated to obtain a FCL which exhibits superior current limit...

Tatsuya Hayashi; Teijiro Mori; Yuuichi Wada

1993-01-01T23:59:59.000Z

489

HIGH TEMPERATURE ELECTROLYZER MATERIALS PROJECT GOAL  

E-Print Network (OSTI)

with compatible electrodes to develop reversible solid oxide fuel cells for low-cost, high efficient power and solid oxide fuel cells. Notable reversible fuel cell achievements have been demonstrated by Proton of traditional oxide ion conductor-based solid oxide fuel cell (SOFC) materials. [2 ,3 ,4 ] Significantly

Mease, Kenneth D.

490

Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions  

SciTech Connect

Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO{sub 2} substrates, we confirm recent theoretical predictions of T{sup 2} temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures.

Vora, Heli; Nielsen, Bent; Du, Xu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York (United States)

2014-02-21T23:59:59.000Z

491

Apparatus for accurately measuring high temperatures  

DOE Patents (OSTI)

The present invention is a thermometer used for measuring furnace temperaes in the range of about 1800.degree. to 2700.degree. C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

Smith, Douglas D. (Knoxville, TN)

1985-01-01T23:59:59.000Z

492

Plasma Resonance and Remaining Josephson Coupling in the Decoupled Vortex Liquid Phase in Layered Superconductors  

Science Journals Connector (OSTI)

We relate the frequency of the Josephson plasma resonance in layered superconductors with the frequency dependent superconducting response. We demonstrate that the sharp resonance can persist even when the global superconducting coherence is broken provided the resonance frequency is larger than the frequency of interlayer phase slips. In this situation the plasma frequency is determined by the average Josephson energy, which can be calculated using the high temperature expansion. We also find the temperature dependence of the average Josephson energy from the Monte Carlo simulations and determine the applicability region of the high temperature expansion.

A. E. Koshelev

1996-10-28T23:59:59.000Z

493

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines  

SciTech Connect

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

Maples, B.; Hand, M.; Musial, W.

2010-10-01T23:59:59.000Z

494

DOE Hydrogen Analysis Repository: High Temperature Electrolysis (HTE)  

NLE Websites -- All DOE Office Websites (Extended Search)

High Temperature Electrolysis (HTE) High Temperature Electrolysis (HTE) Project Summary Full Title: High Temperature Electrolysis (HTE) Project ID: 159 Principal Investigator: Steve Herring Brief Description: A three-dimensional computational fluid dynamics (CFD) model was created to model high-temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). A solid-oxide fuel cell model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. Keywords: Solid oxide fuel cell; solid oxide elctrolysis cell; nuclear; model Purpose Assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Performer Principal Investigator: Steve Herring

495

Theory of reduced superfluid density in underdoped cuprate superconductors  

E-Print Network (OSTI)

The critical temperature of an underdoped cuprate superconductor is limited by its phase stiffness rho. In this paper we argue that the dependence of rho on doping x should be understood as a consequence of deleterious competition...

Lee, Wei-Cheng; Sinova, Jairo; Burkov, A. A.; Joglekar, Yogesh; MacDonald, A. H.

2008-01-01T23:59:59.000Z

496

Neutron scattering study of the iron based superconductors.  

E-Print Network (OSTI)

??In most iron-based and copper-oxide superconductors, the Tc [superconducting critical temperature] gradually increases upon charge carrier doping or isovalent doping. In the under-doped regime of (more)

Wang, Miaoyin

2013-01-01T23:59:59.000Z

497

Universality of critical magnetic field in holographic superconductor  

E-Print Network (OSTI)

Holographic superconductors with constant external magnetic field have been investigated by analytical matching method. It has been shown that the critical temperature and critical magnetic field can be calculated in non-zero temperature. Meissner effect has been observed in such superconductors. The relationship between normal entropy mode and superconductor with Bekenstein upper bound has been studied. Universal relation between black hole mass $ M$ and critical magnetic field $H_c$ has been proposed as $\\frac{H_c}{M^{2/3}}\\leq 0.60045$.

Davood Momeni; Ratbay Myrzakulov

2014-01-13T23:59:59.000Z

498

High-Pressure and High-Temperature Powder Diffraction  

Science Journals Connector (OSTI)

...pressure and varies the motor speed is often used...12.398 is from the quantum mechanical relationship...detectors could in the future reduce data collection...kind of studies in the future. Other more fundamental...addressed in the near future. Temperature gradients...

Yingwei Fei; Yanbin Wang

499

High temperature alkali corrosion of ceramics in coal gas  

SciTech Connect

High temperature alkali corrosion has been known to cause premature failure of ceramic components used in advanced high temperature coal combustion systems such as coal gasification and clean-up, coal fired gas turbines, and high efficiency heat engines. The objective of this research is to systematically evaluate the alkali corrosion resistance of the most commonly used structural ceramics including silicon carbide, silicon nitride, cordierite, mullite, alumina, aluminum titanate, zirconia, and fireclay glass. The study consists of identification of the alkali reaction products (phase equilibria) and the kinetics of the alkali reactions as a function of temperature and time.

Pickrell, G.R.; Sun, T.; Brown, J.J.

1992-05-27T23:59:59.000Z

500

Method for Synthesizing Extremeley High Temperature Melting Materials  

DOE Patents (OSTI)

The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Saboungi, Marie-Louise and Glorieux, Benoit

2005-11-22T23:59:59.000Z