Published for the Division of Materials Sciences, Office of Basic Energy Sciences, USDOE, under Contract W-7405-eng-82 with the Ames Laboratory, Iowa State University. Funded by DMS/BES/USDOE, ARPA, ONR, EPRI, and other agencies, organizations, and individuals.
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The following Nota Bene is contributed by Sreeparna Mitra, Project Director and Editor of High-Tc Update, and Vladimir Kogan, Physicist at the Ames Laboratory (USDOE). John R. Clem, our Science Editor, is currently on travel.
YBa2Cu3O7
Enhancement of the critical temperature Tc in YBa2Cu3O7-d by low-energy electron irradiation (E < 40 keV) is reported by S. Tolpygo (Stony Brook) et al. and the effect contrasted to Tc suppression by high-energy particle irradiation. The authors observe a factor of two increase in resistivity and changes in the Hall coefficient. These transport property changes can be explained as being caused by disruption of the conductivity in CuO chains by radiation-induced chain oxygen defects.
A preprint by J. D. Vienna (Alfred U.) et al. explores the use of Costabilized YBa2Cu3Oy as substrate materials for bulk superconductors. The authors characterized coils with a continuous superconducting path at 77 K fabricated from the superconductor/substrate composites, and investigated Co diffusion into the superconducting layers. Optimal processing conditions are also discussed.
Bi Cuprates
Studies of transport critical current, magnetization, magnetic flux penetration, and microstructure of pressed and rolled Ag-clad (Bi,Pb)2Sr2Ca2Ca3Ox tapes are reported by M. Polak et al. (Wisconsin) as a function of bending strain. The study finds that transport critical currents remain unchanged for pressed samples until a bending strain of ~0.2% then decrease sharply, whereas the magnetization signals continuously and smoothly decrease even with small bending strains until strains greater than ~0.3%, at which point the width of the magnetization curves become saturated and the transport critical currents become nearly zero. In contrast, for samples rolled between heat treatments critical currents begin to decrease with very small strains and decrease more sharply at a strain of ~0.15%. The authors attribute these behaviors to different patterns of the residual preferentially oriented crack networks in rolled and pressed tapes and the different paths of transport and magnetization currents.
A new set up for studying the flux-transformer effects in Bi-2212 is reported by M. Trawick et al. (Ohio State). By using an argon ion mill to etch two (or more) channels into the top surface of the crystal, the authors reproduce effects of the flux transformer with a better control over active sample dimensions. This arrangement allows channeling of the current into the bottom part of the crystal. A sharp dissipation peak is observed in zero applied field between 87 K and 89 K and is attributed to the Josephson coupling of thermally excited pancake vortices.
Magnetic properties of aligned Bi-2223 single crystals have been used to determine the irreversibility line in a paper by Shaoyan Chu et al. (Carnegie Mellon). The data shows a weak pinning state in comparison with polycrystalline samples, and magnetic relaxation data indicate the effective pinning potential to be a strongly non-linear function of current density Jc(H,T).
Thin Films
Series arrays of 365 shunted YBa2Cu3O7-x Josephson junctions on yttriastabilized zirconia bicrystals were investigated by A. M. Klushin et al. (Juelich) under microwave irradiation in the K band. Sub-arrays of up to 39 junctions were synchronized to the external microwave power at 15 K. The authors report that although there was a considerable spread in the critical currents of the junctions in the microwave bias current distribution, a first Shapiro step with height of 30% of the total critical current of the sub-array was obtained by using an external shunt resistor thus reducing the spread of normal resistances to 5%. The authors suggest use for such cryoelectric circuits in voltage standards and precision digital-analog converters.
A preprint by A. Goyal et al. (Oak Ridge) reports epitaxial deposition of YBa2Cu3Ox thick films on biaxially textured metal substrates (RaBiTs substrates). The technique uses well established industrially scalable thermomechanical processes to impart strong biaxial texture to a base metal followed by vapor deposition of epitaxial buffer layers (metal and/or ceramic) to yield chemically compatible surfaces. The authors report that YBa2Cu3Ox films grown on these surfaces have Jc exceeding 10^5 A/cm^2 at 77 K in zero field.
Preparation parameters were optimized by L. Mechin (Grenoble) et al. for growth of epitaxial YBa2Cu3O7-d films on CeO2/YSZ buffered Si substrates. The authors achieve a Tc of 88.5 K and critical current densities above 10^6 A/cm^2 at 77 K in the 40-nm thick films, and have used the films to fabricate sensitive suspended bolometers.
Intrinsic Josephson effects for current flow perpendicular to the CuO2 planes were studied in a paper by M. Veith et al. (Jena) in Tl-Ba-Ca-CuO thin films deposited on step edges in LaAlO3 substrates, with samples specially prepared such that microbridges across such steps act as stacks of Josephson junctions with current flow perpendicular to the CuO2 planes. The authors observed up to 130 individual stacks exhibiting I_cR_Nproducts of up to 26 mV per junction.
The dependence of ramp geometry on high angle or low angle ion-beam etching, used to structure ramp-type Josephson junctions based on RBa2Cu3O7-d superconductors, is investigated in a preprint by K. Verbist (Antwerp) et al. using cross section transmission electron microscopy. The authors also use electron microscopy to study the surface quality, interfaces and crystal defects.
A preprint by F. Dillmann (Juelich) et al. reports measurements of the performance of dc SQUIDs fabricated from YBa2Cu3O7-d films as a function of the SQUID inductance and normal resistance of the step-edge Josephson junctions, and compares results to theoretical predictions. The authors also develop a process for adjusting critical currents and obtaining high normal resistance at the junctions.
Borocarbides
A preprint by B. Knigge et al. (San Diego) reports the search for new superconductors in the Y-Ni-B-C system using a phase spread alloy technique from which thin films with different Y/Ni ratios are obtained. The authors found that the critical temperature Tc is seen to vary with stoichiometry showing the highest Tc for the Y/Ni ratio of 1/2 corresponding to the YNi2B2C phase. No other superconducting phases with Tc greater than 10 K were found, and a search in YxNiB(C1-zNz)y and YxNiBNy phases showed no superconductivity. C60
A millimeter-sized single crystal of Rb3C60 with Tc = 30 K and a transition width Delta-Tc < 1 K was grown by S. Chu et al. (Carnegie Mellon). The authors present magnetization data and determine lower critical field H_[c1], upper critical field H_[c2], the coherence length xi, and the penetration depth lambda, which are found to be significantly different from reported results on powder specimens. Hysteresis and magnetic relaxation measurements are used to determine the nominal critical current density Jc and effective pinning potential U_[eff] respectively.
The lower critical field H_[c1] for superconducting K3C60, Rb3C60, and RbCs2C60 was determined by V. Buntar et al. (Wien) from trapped magnetization measurements. In contrast to previous reports, the authors find smaller values of H_[c1] of the order of 1.5 mT and show that these values are not related to breaking of Josephson junctions between superconducting grains but represent intrinsic values for fullerene superconductors. From their measurements, the authors estimate the penetration depth to be ~800 nm. In another preprint, V. Buntar et al. measure long-term magnetic relaxation in crystalline K3C60 samples in a wide range of temperatures and magnetic fields.
Other Materials
The specific heat of single crystals of HgBa2Ca2Cu3O8+d and HgBa2CuO4+d has been measured by A. Carrington (Grenoble) et al. in fields up to 7 T by a sensitive ac method for measuring microgram-sized samples. For both materials there is evidence of strong thermal fluctuations in the specific heat which has a quasi-logarithmic divergence at Tc in zero field. The almost symmetric shape of the anomaly is in sharp contrast to that observed in YBCO, and seems to be intrinsic to the quasi-twodimensional high-Tc superconductors. In increasing field, there is a strong reduction in the height of the anomaly with the peak position being only weakly shifted to lower temperatures. Applicability of fluctuation theories to the data is discussed.
Sintered samples of Nd1-2xCaxPrxBa2Cu3O7-d (x=0, 0.025, 0.050, and 0.10) have been studied in a preprint by P. Lundqvist (Royal Institute) et al. by resistivity measurements, x-ray and neutron diffraction, and from calculated bond-valence sums. Results indicate that doping of equal amounts of Ca-Pr results in charge-neutral doping in Nd-123. The c axis length and cell volume decreases and the Cu2-O4 distance increases with doping. The average CuO2 plane distance supports a Pr valence of +4 at low doping levels and at higher doping levels is +3.
Thermoelectric power and superconducting transition temperatures have been systematically measured by Z. J. Huamg (Taiwan) et al. for the series of Dy1-xPrxBa2Cu3O7-d with 0 <= x <= 0.6. Results indicate that Tc suppression with Pr doping comes mainly from the hole-depletion effect.
Copper oxycarbonate thin films of the (CaCuO2)m(Ba2-xAxCuO2CO3)n (A=Ca,Sr) systems have been deposited by W. Prellier et al. (CRISMAT) using pulsed-laser deposition on (100) LaAlO3 and (110) NdGaO3 substrates. The authors discuss structures and structural mechanisms and do not observe diamagnetic transitions in any of the films down to 5 K.
Vortices
The ongoing series of experiments on simultaneously measuring the magnetization, resistivity, and IV characteristics of single crystal of Y-123 is reviewed by G. Crabtree (Argonne) et al. The group studies melting transition in the flux-line lattice in static and dynamic regimes. Part of this work has been reported in a recent paper [see Phys. Rev. Lett, 77, 2073 (1996)]. Interestingly, while the magnetization jump at the melting point remains the same in the static and moving vortex systems, the resistivity drop is different in these two cases.
Using a one-dimensional model of Brownian motion of vortices over pinning wells, Ch. Goupil et al. (CRISMAT) derive the current-voltage characteristics E(J). The model describes both linear and nonlinear regimes of the E(J) curves within a single particle model. Thermally activated flux flow (TAFF) and flux flow (FF) are two limits of the dissipative process at low and high currents, respectively.
Theory
Experimental data by J. Mannhart et al. [see High-Tc Update, Vol. 10, No. 7 (1996)], that reported spontaneous delocalized magnetic flux at 45-degree grain boundaries in YBCO are discussed theoretically in two preprints by M. Walker et al. (U. Toronto). The model developed is based on the assumption that twin boundaries in orthorhombic materials may impose the odd reflection symmetry upon the order parameter, which then has opposite signs on two sides of the boundary. If the twin boundaries end at the 45-degree junction, one has an odd number of pijunctions which are known to have the superconducting ground state with a vortex containing half-flux quantum at the meeting point. The authors conclude that the data can be explained by orthorhombicity of YBCO as well as by the d-wave assumption (which provides the phase difference of pi at the 45-degree boundary).
The anomalous NMR relaxation rate and Knight shift in the YBCO contrast notably with conventional BCS theory for s-wave models. D. Djajaputra and J. Ruvalds (U. Virginia) find that a d-wave energy gap on a nested Fermi surface with a large ratio 2Delta_0/Tc = 11 fits the data. The authors explain this by using a temperature-dependent pairing interaction. The spin fluctuation pairing mechanism involves the susceptibility, which is reduced above Tc by damping but recovered at low T's due to depleted available scattering states (the superconducting energy gap). Association of the large gap at zero temperature with the quasiparticle damping shows how the electron collisions reduce Tc to the 100 K range found in cuprates.
Applications
A preprint by M. Jeffery et al. (UC-Berkeley) et al. develops a new type of voltage state superconducting digital logic for ultra-speed operation. The authors use a Monte Carlo optimization method such that gates and complex circuits have a high theoretical yield at 5-10 GHz in spite of process variations inherent in Josephson fabrication technology.
Bulk-melt textured YBCO disks have been developed by G. Fuchs (Dresden) et al. for use as trapped field magnets and in superconducting bearings. The authors report a trapped field of 1 T at 77 K and 8.5 T at 51.65 K between two disks. A superconducting magnetic bearing has been built up of two YBCO rings and two concentric NdFeB ring magnets between them. A static levitation force of 25 N has been achieved and a high-speed motor with two bearings have been tested at 77 K.
Using electro-optic sampling technique, Mikael Lindgren (Rochester) et al. have characterized the photoresponse of current-biased YBa2Cu3O7-x photodetectors designed as microbridges patterned in 100 nm thick expitaxial films grown on LaAlO3 substrates. Results indicate that a simple YBCO microbridge can operate as a ~100 GHz bandwidth photodetector.
Overviews
Progress in the quest to understand the electronic basis for high-Tc superconductivity is reviewed by J. Ruvalds (Virginia). The author reviews work in infrared conductivity, Hall effect, spin susceptibility, Raman spectra, NMR relaxation, Knight shift, and microwave surface resistance of the cuprates; and considers possible theoretical explanations. Mechanisms for high-temperature superconductivity are discussed in the context of d-wave symmetry and relevant spinfluctuation concepts. Novel states such as holon and spinons, spin bags, and anyons are discussed and guides to calculations for t-J models and Monte Carlo simulations are presented. (136 refs.).
Transport and magnetic measurements for the RNi2B2C series are reviewed by D. G. Naugle et al. (Texas A& M). The authors discuss the influence of anisotropy on magnetic and superconducting phase boundaries for HoNi2B2C and map out an anisotropic magnetic phase diagram for this material. The differences in behavior for non-magnetic, magnetic, and heavy-fermion type RNi2B2C for the different rare earths are discussed in the context of resistivity and thermopower measurements. (41 refs.).
Contributed by Sreeparna Mitra and Vladimir Kogan
High-Tc Update is available without charge to interested persons. Recipients are expected to participate in this information exchange by sending us preprints, reprints, meeting news, research news, etc. Contributions to defray the cost of newsletter printing and mailing are welcome.
This section describes progress in manufacturing, product development, and technology transfer in the high-Tc superconductivity field. Please send your contributions (product development information, news regarding technology transfer efforts, or any information you would like to share about your corporation or laboratory) to the editor.
A program initiated by EURUS Technologies, Inc., and the National High Magnetic Field Laboratory (NHMFL), plans to co-develop and test a highcurrent lead fabricated with HTS material. The program will test the mechanical, electrical, and thermal properties of this new class of current leads under varying cryogenic conditions and aims to produce 10^4 A encapsulated, superconducing current leads suitable for deployment in ultrahigh magnetic field applications such as magnetic energy storage and new magnets systems for materials processing. The leads will eventually be used in the NHMFL systems such as the 45 T hybrid magnet. Contact Janet Patten, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310; telephone (904) 644-9651.
The U.S. Department of Energy announced a $21 million cost-sharing program with American Superconductor Corporation (ASC) and Reliance Electric, that aims to produce the first high-horsepower commercialscale electric motor using high temperature superconductors. The program, which is an extension of development work done by Reliance and American Superconductor since 1989, has significance for industrial users of large electric motors with outputs of 1,000 horsepower and higher. Contact American Superconductor Corporation, Two Technology Drive, Westborough, MA 01581; telephone (508) 836-4200; telefax (508) 836-4248.
Contributed by Sreeparna Mitra
R. Adam, W. Kula, Roman Sobolewski, J. M. Murduck, and C. PettietteHall, "Laser Trimming of Y-Ba-Cu-O Step-Edge Josephson Junctions." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; to be published in IEEE Trans. on Appl. Supercond. Department of Electrical Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627; e-mail adam@ee.rochester.edu.
C. D. Batista and A. A. Aligia, "Resonance-Valence-Bond Superconductivity in CuO2 Planes." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia, Atomica, 8400 S.C. de Bariloche, ARGENTINA. 74.20.Mn; 75.10.Jm; 75.40.Mg.
E. V. Blinov, R. Laiho, E. Laehderanta, A. G. Lyublinsky, and K. B. Traito, "Relaxation of Trapped Magnetic Moment in Thin YBaCuO Films at Incomplete Flux Penetration." To be published in Physica C (in press). Contact E. Laehderanta, Wihuri Physical Laboratory, University of Turku, 20500 Turku, FINLAND; telephone +358 21 231 9836; e-mail erlah@sara.cc.utu.fi. 74.76.Bz; 74.60.Ge.
V. Buntar, F. M. Sauerzopf, and H. W. Weber, "Lower Critical Fields of Alkali Metal Doped Fullerene Superconductors." To be published in Phys. Rev. Atominstitut der OEsterreichischen Universitaeten, A-1020 Wien, Schuettelstr. 115, AUSTRIA; telephone +43 1 727 01 296; telefax +43 1 728 9220; e-mail buntar@ati.ac.at. 74.25.Ha; 74.60.Ec; 74.70.Wz.
V. Buntar, F. M. Sauerzopf, H. W. Weber, J. E. Fischer, H. Kuzmany, M. Haluska, and C. L. Lin, "Thermally Activated Flux Creep in K3C60 Single Crystals." To be published in Phys. Rev. Atominstitut der OEsterreichischen Universitaeten, A-1020 Wien, Schuettelstr. 115, AUSTRIA; telephone +43 1 727 01 296; telefax +43 1 728 9220; e-mail buntar@ati.ac.at. 74.25.Ha; 74.60.Ge; 74.70.Wz.
X. W. Cao, J. Fang, Z. H. Wang, X. J. Xu, and K. B. Li, "Anisotropy and Field Dependence of Critical Current Density in YBa2Cu3O7-d Epitaxial Thin Films." Submitted to J. Appl. Phys. High Magnetic Field Laboratory, Institute of Plasma Physics, Academia Sinica, Hefei 230031, PEOPLE'S REPUBLIC OF CHINA.
A. Carrington, C. Marcenat, F. Bouquet, D. Colson, and V. Viallet, "Specific Heat of Hg-Based High Temperature Superconductors Near Tc." Presented at the XXI Int. Conf. on Low Temperature Phys. (LT21), Prague, Czech Republic, Aug. 8-14, 1996; to be published in Czech J. Phys. Loomis Laboratory of Physics, University of Illinois at UrbanaChampaign, 1110 West Green Street, Urbana, IL 61801; telephone (217) 244-4589; telefax (217) 333-9819; e-mail tonyc@alecto.physics.uiuc.edu.
Durga P. Choudhury, Balam A. Willemsen, John S. Derov, and S. Sridhar, "Nonlinear Response of HTSC Thin Film Microwave Resonators in an Applied dc Magnetic Field." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. 112 Dana Research Center, Department of Physics, Northeastern University, Boston, MA 02115; telephone (617) 373-2948; telefax (617) 373-2943; e-mail dpc@neu.edu or http://sagar.physics.neu.edu/.
Shaoyan Chu and Michael E. McHenry, "Irreversibility Lines and Pinning Force Density of Aligned (Bi,Pb)2Sr2Ca2Cu3Ox Single Crystals." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996. Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890; telephone (412) 268-7597 or 2700; telefax (412) 268-1513 or 7596; e-mail sc79@andrew.cmu.edu.
Shaoyan Chu and Michael E. McHenry, "Synthesis and Superconducting Properties of a Rb3C60 Single Crystal." Submitted to Phys. Rev. B. Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213-3890; telephone (412) 268-7597 or 2700; telefax (412) 268-1513 or 7596; e-mail sc79@andrew.cmu.edu.
G. W. Crabtree, W. K. Kwok, U. Welp, J. A. Fendrich, and B. W. Veal, "Static and Dynamic Vortex Transitions in Clean YBa2Cu3O7." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov. 74.60.Ge; 74.72.Bk.
P. Diko, I. Sargankova, M. Reissner, and W. Steiner, "Grain Growth, Microstructure and Magnetic Behavior of YBa2Cu3O7-x(123)-Y2BaCuO5(211) Composites Prepared by Sol-Gel." To be published in Physica C (in press). Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04353 Kosice, SLOVAKIA.
F. Dillmann, V. N. Glyantsev, and M. Siegel, "Performance of YBa2Cu3O7-d dc SQUIDs with High-Resistance Step-Edge Junctions." To be published in Appl. Phys. Lett. Institut fuer Schicht- und Ionentechnik (ISI), Forschungszentrum Juelich GmbH (KFA), D-52425 Juelich, GERMANY.
D. Djajaputra and J. Ruvalds, "NMR Spectra in High Temperature Superconductors." Department of Physics, University of Virginia, Charlottesville, VA 22903. J. Ruvalds' telephone (804) 924-6796; telefax (804) 924-4576; e-mail jr7k@virginia.edu. 74.20.-z; 74.20.Mn; 74.25.-q; 74.25.Nf.
W. H. Fietz, R. Quenzel, H. A. Ludwig, K. Grube, S. I. Schlachter, F. W. Hornung, T. Wolf, A. Erb, M. Klaeser, and G. Mueller-Vogt, "Giant Pressure Effect in Oxygen Deficient YBa2Cu3Ox." To be published in Physica C. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY.
S. Friemel, C. Pasquier, and D. Jerome, "Magnetoresistivity in the Vortex Liquid Phase of k-(BEDT-TTF)2Cu(NCS)2." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Laboratoire de Physique des Solides, Universite Paris-Sud, Batiment 510, F-91405 Orsay Cedex, FRANCE; telephone +33 1 69 41 53 58; telefax +33 1 69 41 60 86; e-mail friemel@lps.u-psud.fr. 74.70.Kn; 74.60.Ec; 74.60.Ge.
Guenter Fuchs, Peter Stoye, Thomas Staiger, Gernot Krabbes, Peter Schaetzle, Wolfgang Gawalek, Peter Goernert, and Alexander Gladun, "Melt Textured YBCO Samples for Trapped Field Magnets and Levitating Bearings." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Contact Thomas Staiger, Institut fuer Festkoerper- und Werkstofforschung Dresden, D-01171 Dresden, GERMANY; telephone +49 351 4659 553; telefax +49 351 4659 537; e-mail t.staiger@ifw-dresden.de.
Haranath Ghosh, "Temperature-Dependent Gap Anisotropy from Modified Spin-Bag Mechanism." To be published in Physica C (in press). Institute of Physics, Sachivalaya Marg, Bhubaneswar 751-005, INDIA; telephone +91 674 418 819; telefax +91 674 481 142; e-mail hng@iopb.ernet.in. 75.30.Fv; 74.72.Hs; 79.60.-i; 74.62.-c.
Ch. Goupil, T. Aouaroun, D. Thopart, J. F. Hamet, and Ch. Simon, "One Dimensional Brownian Motion Model for Transport Measurments in HighTemperature Superconductors." To be published in Phys. Rev. B. ISMRA, Laboratoire CRISMAT, Boulevard de Marechal Juin, F-14050, Caen, Cedex, FRANCE; telephone +31 4526 10; telefax +31 95 1600; e-mail physol@crismat.ismra.fr. 74.60.Ge; 74.60.Jg; 74.40.+k.
A. Goyal, D. P. Norton, J. D. Budai, M. Paranthaman, E. D. Specht, D. M. Kroeger, D. K. Christen, Q. He, B. Satfian, F. A. List, D. F. Lee, P. M. Martin, C. E. Klabunde, E. Hartfield, and V. K. Sikka, "High Critical Current Density Superconducting Tapes by Epitaxial Deposition of YBa2Cu3Ox Thick Films on Biaxially Textured Metals." To be published in Appl. Phys. Lett. Oak Ridge National Laboratory, P. O. Box 2008, Oak Ridge, TN 37831-6116.
K. E. Gray, D. G. Steel, J. D. Hettinger, D. J. Miller, B. R. Washburn, M. Ware, J. T. Parkman, M. E. Yoder, C. Moreau, and M. M. Eddy, "Effects of Vortex-Vortex Interactions on Ion-Track Pinning in High-Tc Superconductors." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
S. K. Hasanain, Shaista Shahzada, A. Mumtaz, and G. S. Bhatti, "ac Susceptibility Hysteresis in Granular Superconductors." To be published in Physica C (in press). Department of Physics, Quaid-i-Azam University, Islamabad 45320, PAKISTAN; telefax +92 51 21 0256.
K. Hashimoto, M. Akiyoshi, A. Wisniewski, M. L. Jenkins, Y. Toda, and T. Yano, "A High-Resolution Electron Microscopy Study of Structural Defects in YBa2Cu4O8 Superconductor." To be published in Physica C (in press). Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152, JAPAN; telefax +81 3 5734 2959; e-mail tyano@nr.titech.ac.jp. Key words: YBCO superconductor, YBa2Cu4O8, YBa2Cu3O7-y, YBa2Cu5O9, HREM, defect structure, planar stacking faults, image simulation.
Z. J. Huang, J. G. Lin, J. J. Lin, J. C. Ho, and C. Y. Huang, "Thermoelectric Power and Superconducting Transition in High-Temperature Superconductors Dy1-xPrxBa2Cu3O7." To be published in Physica C (in press). Contact J. G. Lin, Department of Physics, National Taiwan University, Taipei, Taiwan, REPUBLIC OF CHINA; telefax +886 2 365 5404. Key words: superconductivity, Pr doping, thermoelectric power, hole depletion. 74.25.Fy; 74.62.Dh; 74.72.Bk.
Mark Jeffery, Willem Perold, and T. Van Duzer, "Superconducting Complementary Output Switching Logic Operating at 5-10 Gb/s." To be published in Appl. Phys. Lett. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720-1770; telephone (510) 643-9562; telefax (510) 642-5854; e-mail markj@swordfish.eecs.berkeley.edu. 85.25.Dq; 85.25.Cp; 84.30.Ey; 85.40.Bh.
D. Y. Jeong, M. H. Sohn, H. S. Kim, L. L. He, M. Cantoni, and S. Horiuchi, "Microstructures in High-Jc Tl-1223/Ag Tapes." To be published in Physica C (in press). Contact S. Horiuchi, National Institute for Research in Inorganic Materials, 1-1 Namiki, Tsukuba, Ibaraki 305 JAPAN; telefax +81 298 51 4976; e-mail horiuchi@nirim.go.jp. Key words: TI-1223/Ag tape, high Jc, microstructure, HRTEM, subgrain boundary, pinning site.
D. C. Johnston, "Magnetic Susceptibility of Sr2CuO3 and SrCu2O3." To be published in Acta Phys. Pol.: Proc. of the Physics of Magnetism 96, Poznan, Poland, June 24-28, 1996. Ames Laboratory-USDOE and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011-3020; telephone (515) 294-5435; telefax (515) 294-0689; e-mail johnston@ameslab.gov. 74.25.Ha; 74.72.Jt; 75.40.Cx.
Dong Ho Kim, Seong Yup Shim, Jong Hyeog Park, Young Hwan Kim, Chang Hoon Kim, Jin Wook Jang, Taek Sang Hahn, Sang Sam Choi, Jeffrey D. Hettinger, David G. Steel, and Kenneth E. Gray, "Effect of Heavy-Ion Irradiation on Transport Properties of YBa2Cu3Ox Films." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
M. Kiuchi, H. Yamato, and T. Matsushita, "Longitudinal Elastic Correlation Length of Flux Lines Along the c-Axis in Superconducting Bi2212 Single Crystal." To be published in Physica C (in prress). Contact T. Matsushita, Department of Computer Science and Electronics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka 820, JAPAN; telefax +81 0948 29 7683; e-mail matusita@cse.kyutech.ac.jp.
A. M. Klushin, W. Prusseit, E. Sodtke, S. I. Borovitskii, L. E. Amatuni, and H. Kohlstedt, "Shunted Bicrystal Josephson Junctions Arrays for Voltage Standards." To be published in Appl. Phys. Lett. Forschungszentrum Juelich GmbH (KFA), D-52425 Juelich, GERMANY; e-mail klushin@isitel1.isi.kfa-juelich.de. 74.50.+r; 74.72.Bk; 85.25.Jw; 85.25.Cp.
B. Knigge, A. Hoffmann, D. Lederman, D. C. Vier, S. Schultz, and Ivan K. Schuller, "Search for New Superconductors in the Y-Ni-B-C System." Submitted to J. Appl. Phys. Contact A. Hoffman, Department of Physics 0350, University of California, 9500 Gilman Drive, La Jolla, CA 920930350; e-mail hoffmann@ucsd.edu. 68.55.Nq; 74.10.+v; 74.72.Ny; 74.76.Db; 81.15.Cd.
C. L. Lin, W. J. Chang, M. Y. Li, C. H. Li, C. C. Chi, and M. K. Wu, "Josephson Coupling Behavior of YBa2Cu3O7-x Bicrystal Grain-Boundary Junctions." To be published in Physica C (in press). Materials Science Center and Department of Physics, National Tsing Hua University, HsinChu, Taiwan, REPUBLIC OF CHINA.
Mikael Lindgren, Marc Currie, Carlo Williams, Thomas Y. Hsiang, Roman Sobolewski, Steven H. Moffat, Robert A. Hughes, John S. Preston, and Frank A. Hegmann, "YBa2Cu3O7-x Thin-Film Picosecond Photodetectors." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Department of Electrical Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627; e-mail lindgren@ee.rochester.edu.
Christoph Ludwig, Qidu Jiang, Juergen Kuhl, and Joerg Zegenhagen, "Electrodynamic Properties of Oxygen Reduced YBa2Cu3O7-x Thin Films in the THz Frequency Regime." To be published in Physica C (in press). Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D70569 Stuttgart, GERMANY; telefax +49 711 689 1615; e-mail ludwig@servix.mpi-stuttgart.mpg.de.
H. A. Ludwig, R. Quenzel, S. I. Schlachter, F. W. Hornung, K. Grube, W. H. Fietz, and T. Wolf, "Hydrostatic and Uniaxial Pressure Effect on Tc of YBa2Cu3Ox." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY.
P. Lundqvist, C. Tengroth, OE. Rapp, R. Tellgren, and Z. Hegedues, "Neutron-Diffraction Studies and Interatomic Distances in Ca-Pr Doped NdBa2Cu3O7-d." To be published in Physica C (in press). Department of Solid State Physics, Royal Institute of Technology, S-100 44 Stockholm, SWEDEN; telefax +46 8 790 69 52; e-mail pieter@ftf.kth.se.
Galina M. Maksimova and Igor L. Maksimov, "On the Mixed State Stability Domain in Thin-Film Superconductors." Department of Theoretical Physics, Nizhny Novgorod University, 23 Gagarin Ave., Nizhny Novgorod 603600, RUSSIA.
MAO Zhiqiang, XU Gaojie, ZHANG Shuyuan, TAN Shun, LU Bin, TIAN Mingliang, FAN Chenggao, XU Cunyi, and ZHANG Yuheng, "Relation of the Superstructure Modulation and Extra Oxygen: Local Structural Distortion in Bi-Based 2201 Phase." Structure Research Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA. 74.72.Hs.; 61.16.Bg; 78.30.Jw.
Laurence Mechin, Jean-Claude Villegier, Guy Rolland, and Frederic Laugier, "Double CeO2/YSZ Buffer Layer for the Epitaxial Growth of YBa2Cu3O7-d Films on Si Substrates." To be published in Physica C (in press). Departement de Recherche Fondamentale sur la Matiere Condensee, SPSMS/LCP, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, FRANCE. Key words: YBaCuO, silicon substrate, epitaxial growth, thickness of buffer layers.
P. K. Mishra, G. Ravikumar, V. C. Sahni, M. R. Koblischka, and A. K. Grover, "Surface Pinning in Niobium and a High-Tc Superconductor." To be published in Physica C (in press). Solid State Physics Division, Bhabha Atomic Research Center, Trombay, Bombay 400 085, INDIA; telefax +91 22 5560 750; e-mail sspd@magnum.barct1.ernet.in.
E. K. Moser and K. Naishadham, "Dielectric Resonators as Microwave Characterization Tools." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Materials Directorate, Wright Laboratory, WrightPatterson Air Force Base, OH 45433-7707.
D. G. Naugle, K.D.D. Rathnayaka, A. K. Bhatnagar, A. C. Du Mar, A. Parasiris, J. M. Bell, P. C. Canfield, and B. K. Cho, "Transport and Magnetic Measurements on Single Crystal Rare-Earth Nickel Borocarbides." Presented at the XXI Int. Conf. on Low Temperature Phys. (LT21), Prague, Czech Republic, Aug. 8-14, 1996; to be published in Czech J. Phys. Department of Physics, Texas A&M University, College Station, TX 778434242.
S. Nicoletti, H. Moriceau, J. C. Villegier, D. Chateigner, B. Bourgeaux, C. Cabanel, and J. Y. Laval, "Bi-Epitaxial YBCO Grain Boundary Josephson Junctions on SrTiO3 and Sapphire Substrates." To be published in Physica C (in press). CNR-Istituto Lamel, Via Gobetti 101, I-40129 Bologna, ITALY; telefax +39 51 639 9216. Key words: grain boundary, texturing, thin films, weak links, Josephson effect.
Eriko Ohshima, Masae Kikuchi, and Yasuhiko Syono, "Superconductivity in TISr2-xCaxYbCu2O7 by Isovalent Cation Substitution." To be published in Physica C (in press). Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980, JAPAN; telefax +81 22 215 2086. Key words: TI cuprate, self-doping, isovalent cation substitution, Cu-O bond length.
C. Pasquier, S. Friemel, and D. Jerome, "The Mixed State of the kappa(BEDT-TTF)2Cu(NCS)2 Organic Superconductor." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Laboratoire de Physique des Solides, Universite Paris-Sud, Batiment 510, F-91405 Orsay Cedex, FRANCE. S. Friemel's telephone +33 1 69 41 53 58; telefax +33 1 69 41 60 86; e-mail friemel@lps.u-psud.fr.
M. Polak, J. A. Parrell, A. A. Polyanskii, A. E. Pashitski, and D. C. Larbalestier, "On the Role of Pre-Existing, Unhealed Cracks on the Bending Strain Response of Ag-Clad (Bi,Pb)2Sr2Ca2Cu3Ox Tapes." Submitted to Appl. Phys. Lett. Applied Superconductivity Center, University of Wisconsin, Madison, WI 53706.
D. Ponnusamy, N. Tralshawala, J. R. Claycomb, J. H. Miller, Jr., K. Ravi-Chandar, and K. Salama, "Processing and Characterization of High Tc Magnetic Shields and Flux Transformers." Preprint #96:097; submitted to the Proc. of the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996. Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 7438201; e-mail preprints@www.tcs.uh.edu.
W. Prellier, A. Tebano, J. L. Allen, J. F. Hamet, B. Mercey, M. Hervieu, and B. Raveau, "Pulsed Laser Deposition of Ba2-xAxCuO2CO3 (A=Ca,Sr) Thin Films, m=0 Member of the Series (CaCuO2)m(Ba2-xAxCuO2CO3)n (A=Ca,Sr)." To be published in Chem. Mater. Laboratoire CRISMAT, CNRS, URA 1318, ISMRA et Universite de Caen, Boulevard du Marechal Juin, F-14050 Caen Cedex, FRANCE; telephone +33 31 45 26 07; telefax +33 31 95 16 00; email films@crcrisu.ismra.fr.
Khandker F. Quader and George A. Levin, "The Origin and Consequences of the 'Gap' in the Cuprate Normal State." To be published in Philos. Mag. B. Department of Physics, Kent State University, Kent, OH 44242; George A. Levin's telephone (216) 672-2402; telefax (216) 672-2959; e-mail levin@mustang.kent.edu.
M. Ruebhausen, N. Dieckmann, A. Bock, and U. Merkt, "Line Shape Analyses of Magnon Raman Spectra of a PrBa2Cu2.7Al0.3O7 Single Crystal." To be published in Phys Rev. B. Institute fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, D20355 Hamburg, GERMANY; telephone +49 40 41 23 42 02; telefax +49 40 41 23 43 68; e-mail ruebhausen@physnet.uni-hamburg.de. 78.30.Hv; 75.30.Et; 74.72.Jt; 74.25.Gz.
M. Ruebhausen, N. Dieckmann, A. Bock, U. Merkt, W. Widder, and H. F. Braun, "Raman Scattering of Magnetic Excitations in Y1-xPrxBa2Cu3yAlyO7-d Single Crystals." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Institute fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, D-20355 Hamburg, GERMANY; telephone +49 40 41 23 42 02; telefax +49 40 41 23 43 68; e-mail ruebhausen@physnet.unihamburg.de.
J. Ruvalds, "Theory Prospects for High Temperature Superconductors." To be published in Supercond. Sci. & Technol. Department of Physics, University of Virginia, Charlottesville, VA 22903; telephone (804) 9246796; telefax (804) 924-4576; e-mail jr7k@virginia.edu.
S. I. Schlachter, H. A. Ludwig, K. Grube, F. W. Hornung, W. H. Fietz, B. Obst, P. Schweiss, T. Wolf, M. Klaeser, and G. Mueller-Vogt, "Tc Variation of (Y1-yCay)Ba2Cu3Ox Single Crystals Under Hydrostatic Pressure." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY.
S. Skanthakumar, J. W. Lynn, and F. Dogan, "Spin Dynamics of Er^[3+] in ErBa2Cu3O7-d." Submitted to J. Appl. Phys. Reactor Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899; e-mail skantha@rrdstrad.nist.gov.
S. Skanthakumar, J. W. Lynn, N. Rosov, G. Cao, and J. E. Crow, "Observation of Pr Magnetic Order in PrBa2Cu3O7." Submitted to Phys. Rev. B. Reactor Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899; e-mail skantha@rrdstrad.nist.gov. 75.25.+z; 74.25.Ha; 74.72.-h.
Roman Sobolewski, Roman Adam, Witold Kula, Wilhelm Markowitsch, Christian Stockinger, Wolfgang Goeb, and Wolfgang Lang, "Photodoping Effect in Y-Ba-Cu-O Josephson Junctions and Thin Films." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Department of Electrical Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627; e-mail sobolewski@ee.rochester.edu.
M. G. Stachiotti, C.R.A. Catlow, C. O. Rodriguez, and N. E. Christensen, "Electronic Structure and Phonon Behavior Under Pressure in YBa2Cu4O8." To be published in Physica C (in press). The Royal Institution of Great Britain, 21 Albemarle Street, London W1X 4BS, UNITED KINGDOM; telefax +44 171 629 3569.
U. Staub, F. Fauth, M. Gutmann, and W. Kagunya, "Magnetic Properties of Tb Doped in YBa2Cu3Ox." To be presented at the 1st European Conference on Neutron Scattering; to be published in Physica B. Swiss Light Source Project, Paul Scherrer Institute, CH-5232 Villigen PSI, SWITZERLAND; telephone +41 56 310 41 18; telefax +41 56 310 31 51; e-mail urs.staub@psi.ch. Key words: crystal fields, high-Tc superconductors, quasi elastic scattering.
V. R. Todt, X. F. Zhang, and D. J. Miller, "Nucleation and Growth of Single- and Multiple-Domain YBa2Cu3Ox Levitators: Influence of Seed Crystallography." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
Sergey K. Tolpygo, J.-Y. Lin, M. Gurvitch, S. Y. Hou, and Julia M. Phillips, "Tc Enhancement by Low Energy Electron Irradiation and the Influence of Chain Disorder on Resistivity and Hall Coeffecient in YBa2Cu3O7 Thin Films." To be published in Physica C (in press). Department of Physics, State University of New York at Stony Brook, Stony Brook, NY 11794-3800; telephone (516) 632-8049; telefax (516) 6328774; e-mail stolpygo@ccmail.sunysb.edu. Key words: electrical resistivity, Hall effect, irradiation effect, normal-state properties, thin films. 74.25.Fy; 74.62.Dh; 74.72.Bk.
E. E. Tornau, P. J. Kundrotas, and A. Rosengren, "Holes Amount and Aging of Quenched Samples of YBa2Cu3O6+x." To be published in Physica C (in press). Contact A. Rosengren, Department of Theoretical Physics, Royal Institute of Technology, S-100 44 Stockholm, SWEDEN; telefax +46 98 790 7171; e-mail ar@theophys.kth.se. Key words: Cu-O chains, hole concentration, oxygen stoichiometry. 74.72.Bk; 61.50.Em; 64.60.Cn.
M. L. Trawick, S. M. Ammirata, C. D. Keener, S. E. Hebboul, and J. C. Garland, "Vortex Coupling in Bi2Sr2CaCu2O8+y Using Controlled Sample Geometry." Department of Physics, Ohio State University, Columbus, OH 43210. 74.25.Dw; 74.25.Fy; 74.60.Ge; 74.72.Hs.
A. L. Vasiliev, E. P. Kvam, F. Foong, and S.-H. Liou, "The Microstructure of (Hg,TI)-Based High Temperature Superconducting Films on LaAIO3 Substrates." To be published in Physica C (in press). Contact E. P. Kvam, School of Materials Engineering, Purdue University, W. Lafayette, IN 47907; telefax (317) 494-1204; e-mail kvam@purdue.edu. Key words: HgBa2Ca1Cu2O6+x, (Hg,TI)-1223, thin films, inclusions, TEM, EDS.
M. Veith, T. Eick, W. Brodkorb, M. Manzel, H. Bruchlos, T. Koehler, H.G. Schmidt, E. Steinbeiss, H.-J. Fuchs, K. Schlenga, G. Hechtfischer, and P. Mueller, "Fabrication and Properties of Intrinsic Josephson Junctions in Thin Films of TI-Ba-Ca-Cu-O." To be published in J. Appl. Phys. Institut fuer Physikalische Hochtechnologie e.V. Jena, Postfach 100 239, D-07702 Jena, GERMANY; telephone +49 3641 302 760; telefax +49 3641 302 799; e-mail iphmv@rz.uni-jena.de.
Martin Veith, Konstantin Kirsch, Thomas Eick, and Erwin Steinbeiss, "YBaCuO/TIBaCaCuO Epitaxial Thin Film Superconducting Multilayers -- a Novel Approach to Intrinsic Josephson Junctions." Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; submitted to IEEE Trans. on Appl. Supercond. Institut fuer Physikalische Hochtechnologie e.V. Jena, Postfach 100 239, D-07702 Jena, GERMANY; telephone +49 3641 302 760; telefax +49 3641 302 799; e-mail iphmv@rz.uni-jena.de.
K. Verbist, O. I. Lebedev, G. Van Tendeloo, M.A.J. Verhoeven, A.J.H.M. Rijnders, and D.H.A. Blank, "Low or High Angle Ar Ion-Beam Etching to Create Ramp-Type Josephson Junctions?" Submitted to Supercond. Sci. & Technol. EMAT, University of Antwerp (RUCA), Groenenborgerlaan 171, B2020 Antwerp, BELGIUM; telefax +32 32 18 02 57; e-mail karen_verbist@ruca.ua.ac.be.
J. D. Vienna, J. A. Taylor, and U. Balachandran, "Processing and Characterization of Cobalt-Stabilized YBa2Cu3Oy as a Substrate for Bulk Superconductors." Submitted to Physica C. New York State College of Ceramics, Alfred University, Alfred, NY 14802. Key words: YBa2Cu3Oy, YBa2Cu(3-x)CoxOy, substrate, coprocessing, characterization.
M. B. Walker, "Mechanism for Magnetic Flux Generation in Grain Boundaries of YBa2Cu3O7-x." To be published in Phys. Rev. B. Department of Physics, University of Toronto, Toronto, CANADA M5S 1A7, CANADA; e-mail walker@physics.utoronto.ca; preprint also available at cond-mat@xxx.lanl.gov (#9608131). 74.20.De; 74.50.+r; 74.72.Bk; 74.62.Bf.
M. B. Walker and J. Luettmer-Strathmann, "Macroscopic Symmetry Group Describes Josephson Tunneling in Twinned Crystals." To be published in J. Low Temp. Phys.: Proc. of the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996. Department of Physics, University of Toronto, Toronto, CANADA M5S 1A7, CANADA; e-mail walker@physics.utoronto.ca. 74.20.De; 74.50.+r; 74.72.Bk; 74.62.Bf.
Hans Weber and Henrik Jeldtoft Jensen, "Monte Carlo Calculation of the Linear Resistance of a Three Dimensional Lattice Superconductor Model in the London Limit." Department of Physics, Lulea University of Technology, S-971 87 Lulea, SWEDEN.
Harald W. Weber, "Flux Pinning by Artificial Defects in High Temperature Superconductors." Presented at the Int. Symposium on Advances in Supercond.: New Materials, Critical Currents, and Devices: Tata Institute of Fundamental Research, Bombay, India, Sept. 17-20, 1996. Atominstitut der OEsterreichischen Universitaeten, A-1020 Wien, AUSTRIA.
C. Wiecko, "The Isotope Effect in the Infinite-Range Hopping Approximation to the Negative U Hubbard Model." To be published in Physica C (in press). Centro Atomico, Bariloche, 8400-S.C. de Bariloche, Rio Negro, ARGENTINA; e-mail wiecko@cab.cnea.edu.ar.
Balam A. Willemsen, J. S. Derov, and S. Sridhar, "Critical State Flux Penetration and Linear Microwave Vortex Response in Y1Ba2Cu3O7-d Films." Submitted to Phys. Rev. B. 112 Dana Research Center, Department of Physics, Northeastern University, Boston, MA 02115. 74.60.Ge; 74.60.-w; 74.60.Jg; 74.76.Bz.
Z. Y. Zeng, Y. Yu, A. M. Sun, X. N. Xu, S. Y. Ding, X. X. Yao, Ren Hongtao, and Xiao Ling, "Surface Pinning and Influence of Field Reduction on Magnetic Relaxation in YBa2Cu3O7 Bulk Sample." To be published in Physica C (in press). Department of Physics and Solid State Physics Institute, Nanjing University, Nanjing 210093, CHINA.
Oct. 1996 - July 1997: Course in Crystal Growth and Epitaxy in Science and Technology, Lausanne, Switzerland. Two semesters. Participants will learn about preparation of crystals, layers, and surfaces. Program includes science and technology of crystal growth and of epitaxial deposition of layers and superlattices; the role of phase relations for crystal growth; crystal and defect chemistry and characterization; control of heat and mass transfer; crystals, layers, and surfaces for applications in micro- and optoelectronics, lasers, non-linear optics, microtechnology, energy technology, solid-state and surface physics, and high-Tc superconductivity; and laboratory and industry visits. Instruction language is English. Cost: 100 Swiss francs per semester. Contact Hans J. Scheel, EPFL, Cristallogenese, Ch. de Bellerive 34, 1007 Lausanne, Switzerland; telephone +41 21 693 4452; telefax +41 21 693 4750.
Nov. 18 - 30, 1996: First Training Course in the Physics of Correlated Electron Systems and High-Tc Superconductors, Vietri sul Mare, Salerno, Italy. Aimed at postdoctoral-level researchers. Intends to promote theoretical research in the field of highly correlated electron systems by interaction between senior and young researchers. Courses open to approx. twenty young European researchers. Registration fee will be $200. Limited number of grants available. Requests for application forms and further information should be sent to F. Mancini, Dipartimento di Fisica Teorica, Universita' di Salerno, Via S. Allende, I-84081 Baronissi (SA), Italy; telephone +39-89-965 322; telefax +39-89-965 275; e-mail mancini@vaxsa.csied.unisa.it.
*Feb. 28 - March 4, 1997: Fifth International Conference on Materials and Mechanisms of Superconductivity and High-Temperature Superconductors (M2S-HTSC-V), Beijing, China. Topics include high-Tc materials; physical properties of high-Tc materials; magnetism and superconductivity; vortices, pinning, and flux melting; thin films and multilayers; Josephson junctions; applications; heavy fermions; organic superconductors; fullerenes; and theory. Exhibition of high-Tc superconducting materials, low-temperature experimental appliances, and cryogenic engineering and refrigeration instruments. Conference language is English. Abstract deadline, September 30, 1996. For information, contact D. Jin, M2S-HTSC-V Secretariat, Cryogenic Laboratory, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100 080, People's Republic of China; telephone +86 10 255 1143; telefax +86 10 256 4049; e-mail djin@cl.cryo.ac.cn. *Note revised abstract deadline.
March 17 - 21, 1997: APS March Meeting -- Focussed Session on Industrial Applications of High-Temperature Superconductor Materials, Kansas City, MO. Sponsored by the APS Forum on Industrial and Applied Physics. Appropriate topics for this session include the following: passive microwave devices for cellular and PCS applications; ferroelectric/HTS tunable microwave devices; junction-based electronics; magnetic-field sensing with SQUIDs, scanning SQUID magnetometers, and SQUID-based picovoltmeters; and HTS tapes, cables, and coils. Papers are solicited. Abstract deadline December 6, 1996. For further information, contact Eric Moser, USAF Wright Laboratory, Electromagnetic Materials Devision (WL/MLPO), Wright-Patterson AFB, OH 45433; telephone (513) 255-4474, ext. 3255; telefax (513) 255-4913; e-mail moserek@ ml.wpafb.af.mil.
*May 12 - 14, 1997: 2nd SIAM Conference on Mathematical Aspects of Materials Science, Holiday Inn Select, Philadelphia, PA. Conference will gather the interdisciplinary community of scientists working on mathematical and computational aspects of materials science. Conference will examine recent methodological advances in areas such as analysis of moving interfaces, fast boundary integral methods, macroscopic consequences of microstructure, and pattern formation due to energy minimization. Will also highlight recent accomplishments in areas such as materials design, synthesis and processing, simulation of phasetransformation dynamics, and stress effects in thin films, and identify promising directions for new developments of a mathematical or computational nature in areas such as atomic-scale modeling, liquid crystals and polymers, magnetic materials, and plasticity. Will include scientists from a broad range of backgrounds, including mechanics, physics, engineering, mathematics, and computational science. Invited presentations include Vortex Physics in Superconductors and NonHermitian Localization by David Nelson (Harvard). Minisymposia also planned on superconductivity. Abstract deadline, Oct. 15, 1996. For further information, contact SIAM, 3600 University City Science Center, Philadelphia, PA 19103-2688; telephone (215) 382-9800; telefax (215) 386-7999; e-mail meetings@siam.org or http://www.siam.org/conf.htm.
*Sept. 7 - 20, 1997: Summer School on Superconductivity in Networks and Mesoscopic Structures, Certosa di Pontignano, Siena, Italy. Aimed at Ph.D. students and postdoctoral researchers. School will provide opportunity for interaction with experts from different fields and include topics such as simulation of complex dynamic systems, quantum and classical theories, Monte Carlo simulations, and others. Application deadline, Oct. 31, 1996. Contact C. Giovannella, Dipartimento di Fisica, Universita di Roma "Tor Vergata", Via della Ricerca Scientifica 1, I-00133 Rome, Italy; telephone +39 6 7259 4524; telefax +39 6 202 3507; e-mail supnet@roma2.infn.it. Information also available at the web site http://wwwas.roma2.infn.it/.
Positions Available: The World Laboratory announces that a scholarship named in honor of the scientist E. R. Caianiello to be awarded annually to a young physicist to work at the International Institute for Advanced Scientific Studies, in Vietri sul Mare, Salerno, Italy and at the Department of Theoretical Physics of the Salerno University. Open to candidates from developing countries working in fields such as quantum field theory, quantum geometry, neural networks, and structural analysis of complex systems. Approx.. scholarship 1200 Swiss Francs/mo. Application deadline, Dec. 1996. For information, contact Anna Esposito, International Institute for Advanced Scientific Studies "E. R. Caianiello", Via G. Pellegrino, 19, I-84019 Vietri sul Mare (SA), Italy; telephone +39 89 761167; telefax +39 89 -761 189 or -965 275; e-mail annesp@vaxsa.csied.unisa.it.
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The information contained herein is intended for limited distribution. Readers are expected to respect the rights of the authors.
Please address all contributions and inquiries to: Dr. Sreeparna Mitra, A219 Physics, Ames Laboratory/Iowa State University, Ames, Iowa 50011-3020. Telephone: (515) 294-3877. Telefax: (515) 294-1134. Telex: 269266. E-mail: MITRA@AMESLAB.GOV or MITRA@IASTATE.EDU.
Project Director/Editor: Sreeparna Mitra
Science Editor: John R. Clem
High-Tc Update, Vol. 10, #19, October 1, 1996.