RABiTS
Progress in the fabrication of rolled Ni substrates, consisting of large biaxially oriented grains with grain orientations within about 5 degrees of each other, was reported by A. Goyal et al. (Oak Ridge) and D. Norton et al. (Oak Ridge) at the recent MRS Spring Meeting in San Francisco. While the resulting substrates should be suitable for the deposition of many high-Tc superconductors, the most significant advances so far have been in the production of high-quality, high-Jc YBa2Cu3O7-d (YBCO) films of thickness about 1 micrometer on buffer layers. Although no preprints are available, further details about rolling-assisted biaxially textured substrates (RABiTS[TM]) can be found in the Technology News section of this issue.
YBa2Cu3O7-d
The magnetic penetration depth in the vortex state of YBa2Cu3O6.95 has been measured by J. E. Sonier et al. (TRIUMF and UBC) as a function of temperature T and magnetic field H applied along the c axis. The internal field distribution in high-quality single crystals was fit assuming a triangular vortex lattice with an average in-plane penetration depth lambda_[ab] = (lambda_a-lambda_b)^[1/2] = 1155(3) Angstroms, extrapolated to T = 0 and H = 0; lambda(T,H) increases linearly with T and H. The authors suggest that the large T-independent increase in lambda_[ab] with H is evidence for a strong nonlinear response as a result of unconventional pairing in the superconducting state.
A preprint by C. Bucci (Parma) et al. presents a mu-SR study of the reduction of both Tc and the condensate density in ceramic YBCO samples upon substitution of Cu by Zn. The authors take this to be strong evidence for nonmagnetic pair-breaking in a d-wave pairing state. Another paper by C. Bucci et al. (Parma) reports studies of zero-field mu-SR precession signals in antiferromagnetic (AF) YBa2Cu3O6+x (0.06 <= x <= 0.39) ceramic samples. Analysis of the temperature and oxygencontent dependencies shows a complex behavior of the magnetic field at the muon site. The authors find that (a) the muon does not diffuse freely above 250 K and (b) mobile holes phase separate, inducing a finite-size reduction of the AF order parameter.
The polarized reflectance spectra have been determined by K. Widder (Karlsruhe) et al. for the (001) plane of single-domain Y1-zPrzBa2Cu3O7d crystals grown in a noncorrosive BaZrO3 crucible. Separating the conductivity of the CuO chains and the CuO2 layers, the authors were able to determine the influence of Pr doping on the two different Cu-O networks.
The influence of hydrostatic pressure up to 1 GPa on Tc in orthorhombic samples of GdBa1.5Sr0.5Cu3Ox (x = 6.63, 6.73, and 6.93) has been studied by M. Baran and I. Fita (Warszawa). The authors found a strong increase of dTc/dP with decreasing x, a behavior different from that found in YBa2Cu3Ox. For GdBa1.5Sr0.5Cu3O6.63, the authors found dTc/dP to be as high as 13.7 K/GPa, higher than that reported for YBa2Cu3O6.71 (11.5 K/GPa) in the region of the ortho(I)-to-ortho(II) transition.
As determined by F. Sandiumenge et al. (Barcelona) from x-ray and transmission electron microscopy, the mosaic structure of YBa2Cu3O7d/Y2BaCuO5 (123/211) directionally solidified composites results from polygonization before the oxygenation step. A topological model based on the observed distribution of preferred subgrain boundary planes is presented. The authors propose that polygonization, which is characteristic of melt-textured 123, produces an intrinsic critical current density limitation in these materials.
A preprint by K. Salama (TCSUH) et al. reports the achievement of highspeed melt texturing of NdBa2Cu3O7-d (Nd-123). Bars of these compounds (50 mm x 5 mm x 5 mm) were processed at rates ranging from 1 mm/h to 200 mm/h through a high temperature gradient. Fully melt-textured microstructures were obtained at processing rates up to 50 mm/h, more than 50 times faster than that employed in the processing of YBa2Cu3O7-d (Y-123). After oxygen annealing, the Nd-123 textured bars showed a Tc onset of 93 K and a 77 K, self-field Jc of 5 x 10^3 A/cm^2. The authors expect these results to improve significantly as more progress takes place.
Bi Cuprates
Details of formation of the (Bi,Pb)2Sr2Ca2Cu3O10+d phase are reported by J.-C. Grivel and R. Fluekiger (Geneve), who performed scanning electron microscope observations on the same location of the surface of a pellet that underwent several heat treatments at 852 degrees for various times. One of the authors' main findings is that the (Bi,Pb)2Sr2Ca2Cu3O10+d phase does not form by a layer-by-layer insertion mechanism from preexisting (Bi,Pb)2Sr2CaCu2O8+d crystallites; instead, it forms through a distinct nucleation and growth process. The authors present a detailed model for the growth of the (Bi,Pb)2Sr2Ca2Cu3O10+d phase from the liquid.
Fundamentals on phase equilibria in the Bi-Pb-Sr-Ca-Cu-O system and on the preparation of (Bi,Pb)2Sr2Ca2Cu3O10+d are presented in a preprint by P. Majewski et al. (MPI-Stuttgart). The authors present phase diagrams showing multiphase regions including the 2223 phase.
The rapid synthesis of phase-pure (Bi,Pb)-2223 powders by an EDTA solgel method is reported by V. Rouessac et al. (Caen). The authors propose a route to accelerate 2223 phase kinetics by improving calcination, sinterings, and intermediate grindings.
The role of the sintering temperature and duration in the formation of the 2223 phase in the stoichiometric compositions Bi2-xPbxSr2Ca2Cu3O10+d (x = 0.35 and 0.4) is reported by D. Pandey (Banaras Hindu) et al. for a semi-wet route using (x PbCO3 +2 SrCO3 + 2 CaCO3) precursors. The authors report the synthesis of high-purity 2223 phase, free from Ca2PbO4, 2212, and 2201 impurity phases, for the x = 0.4 composition within a total heat-treatment duration of 38 h, including 24 h of calcination. The authors found the single-phase 2223 phases to be of good compositional homogeneity.
The connectivity of rolled and pressed Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3O10+d tapes through three deformation and heattreatment cycles has been examined by J. A. Parrell et al. (WisconsinMadison). Magneto-optical imaging with fields applied perpendicular to the rolling plane revealed that flux penetrated the superconducting core mainly through defects oriented perpendicular to the direction of current flow in rolled samples, and parallel to the direction of current flow in pressed samples. In samples that had received more than one heat treatment, the authors believe that flux penetrates through cracks produced during the deformation steps which do not heal during subsequent heat treatments because of the lack of sufficient residual liquid phase.
A preprint by L. Gherardi (Pirelli) et al. reports on the dependence of the critical current density of monofilamentary (Bi-Pb)-2223 tapes. The authors used several experimental arrangements to sort out the effects of self-fields, which are appreciable at the edges of single tapes. The authors conclude that the side portions of the tapes, very close to the edges, carry a higher current density than the interior portions of the tapes.
The characterization of monofilamentary and multifilamentary Bi-2223 tapes by magnetic ac loss measurements is reported by G. C. Montanari (Bologna) et al. The authors find that the magnetic properties depend strongly on the technological processes used, and differ significantly between mono- and multifilamentary specimens.
Other Cuprates
[63]^Cu NMR spectra and T_1 and T_[2G]measurements in single crystals of underdoped, three-layered HgBa2Ca2Cu3O8+d (Hg-1223, Tc ~~ 115 K) are reported by M.-H. Julien (Grenoble) et al. The authors find that a spin gap opens below T* ~~ 230 K and that the characteristic energy of the spin fluctuations is higher than that in YBa2Cu3O7-d. The authors attribute both features to the higher Tc in Hg-1223. Below T*, [63]^T_1 has the same temperature dependence in the three CuO2 planes, which is difficult to explain by pure interlayer spin pairing.
The intercalation of FeCl3 between the BiO layers in Bi2Sr2CaCu2O8+d to form stage-I intercalated (FeCl3)Bi2Sr2CaCu2O8+d is reported by X. H. Chen and L. Z. Cao (Hefei). No superconducting transition was found in the resulting material down to 5 K. The suppression of superconductivity may be due to ferromagnetic ordering of the Fe ions.
A preprint by M. R. Palacin (Barcelona) et al. reports attempts to perform cationic substitutions and doping in the layered perovskites Ln2Ba2Cu2Ti2O11 (Ln = La, Nd, Eu, and Tb). The authors report that La2Ba2Cu2.15Ti1.85O11 oxidized under high oxygen pressures resulted in oxygenation and doping of this material. However, this oxide does not show signs of superconductivity down to 4 K, presumably because of the long Cu-O bond length in its structure.
The structure of the newly synthesized Pb-based cuprate (Pb0.5M0.5)(Sr0.9Ho0.1)2(Ho0.7Ce0.3)2Cu2Oy (M = Pb and Cd) is reported in a preprint by H. M. Luo (Beijing and Hefei) et al.
Vortices
Columnar defects (CD's) inclined at 45 degrees from the c axis have been studied experimentally by V. Hardy et al. in single crystals of Bi2Sr2CaCu2O8+d (Bi-2212), Tl2Ba2CaCu2O8+d (Tl-2212), Tl2Ba2Ca2Cu3O10 (Tl-2223), Tl2/3Bi1/3Ba2Ca1Cu2O7 [(Tl,Bi)-1212], and YBa2Cu3O7-d (Y123). In each case, magnetic hysteresis loops were recorded with the magnetic field parallel to the columns (H_a||CD) and perpendicular to them (H_a perp. to CD). Two regimes were found: an isotropic pinning enhancement [Jc(H_a perp. to CD) = Jc(H_a||CD)] at low temperatures and a directional effect [Jc(H_a perp. to CD) < Jc(H_a||CD)] at higher temperatures. The isotropic regime is attributed to the occurrence of a totally adjusted state, where the vortices zigzag between the CD's and the ab planes, keeping their mean direction along the applied field. The authors present an analysis for the crossover between the two regimes, which accounts for the observed influences of the temperature and the anisotropy. The vanishing of the difference between Jc(H_a perp. to CD) and Jc(H_a||CD) at zero field is discussed in terms of a complete reorientation of the vortices along the CD's (flux flop) at low fields, even when H_a is nearly perpendicular to the CD's.
The free energy and equilibrium magnetization in highly anisotropic layered superconductors with strong defects produced by irradiation have been calculated by L. N. Bulaevskii (Los Alamos) et al. The authors account for the entropy associated with different configurations of pancakes inside and outside of strong defects. The calculation shows how magnetization measurements provide information on pinning energy and indicate the magnetic fields and temperatures at which pancake vortices are trapped inside strong defects. The authors also discuss magnetization behavior that may signal decoupling of pancakes inside columnar defects.
The interplay between vortex-loop unbinding at T = T_v and vortexlattice melting at T = T_m in type-II superconductors is discussed by A. K. Nguyen (Trondheim) et al. The authors find that melting is due to nucleation of vortex loops parallel to the c axis, connected to vortex lines, and that T_m decreases with increasing anisotropy, eventually approaching a finite value. For moderate anisotropy, longitudinal phase coherence is lost at T_v > T_m because of ab-plane vortex-loop unbinding, with loops located in the vicinity of thermally nucleated vortex-line defects. For large anisotropy, longitudinal phase coherence is lost at T_v < T_m because of nucleation of ab-plane vortex loops uncorrelated to vortex lines. The authors note that the vortex-loop unbinding is a finite-field counterpart of the inverted XY transition [C. Dasgupta and B. I. Halperin, Phys. Rev. Lett. 47, 1556 (1981)] and is confirmed experimentally [E. Zeldov et al., Nature 375, 373 (1995)].
The nature of driven motion of a vortex solid in the presence of a planar pinning defect has been investigated by G. W. Crabtree et al. (Argonne) using large-scale simulations based on the time-dependent Ginzburg-Landau equations. Three dynamic phases are identified and characterized by the relative positional and velocity correlations: elastic flow, correlated plastic flow, and uncorrelated plastic flow.
Thin Films
Atomic layer-by-layer molecular-beam epitaxy (ALL-MBE) has been used by I. Bozovic and J. N. Eckstein (Varian) to fabricate an SIS tunnel junction. The authors replaced the central Ca layer in BiSr2Ca7Cu8Ox (Bi-1278) by Dy to produce a compound that contains, within a single unit cell, the bottom superconducting electrode, an insulating layer (less than 1 nm thick), and the top superconducting electrode. The authors report that such intracell Josephson junctions exhibit very sharp quasiparticle tunneling characteristics, which are consistent with tunneling between 2D superconductors with d-wave pairing.
(Pb2Cu)Sr2(Eu,Ce)nCu2Oy (n = 3-8, Pb-32n2) has been synthesized by S. Ikegawa and Y. Motoi (Toshiba) via sequential deposition using the MBE technique. The authors suggest that this layered cuprate, which has a multiple-stacked fluorite-type block, will be suitable for use in trilayer Josephson junctions. The thickness of the fluorite block, which acts as an intracell barrier, has been controlled up to 2.2 nm (n = 8).
As reported by J. T. McDevitt (Texas-Austin) et al., a method has been developed for the spontaneous adsorption of monolayer films of molecular reagents onto the surfaces of high-Tc superconductors. Such monolayers have been shown to greatly influence the diffusion of molecular compounds such as H2O to the superconductor surface. Thus, the corrosion resistance, adhesion, and wetting properties of the high-Tc material can be tailored through judicious choice of the adsorbate molecule. The authors suggest that this method can lead to improvements in superconductor packaging, device processing, and the preparation of corrosion-protection layers.
Thin Tl2Ba2CaCu2O8+d (Tl-2212) films with Tc = 95-108 K and Jc(77K) ~~ 10^5 A/cm^2 have been grown on Al2O3 substrates by Q. Xiong (Arkansas) et al. Mirror-like, highly c-axis-oriented films were grown on highly textured YSZ buffer layers deposited by ion-beam-assisted deposition via laser ablation. The authors also report the use of IBAD to grow YBCO/YSZ/SiO2/YSZ/YBCO/LaAlO3 multilayers with Jc(77K) ~~ 6x 10^5 A/cm^2 in the top YBCO layer. The results suggest that it is possible to use inexpensive polycrystalline substrates to fabricate good HTS films.
Thin films of YNi2B2C have been grown by A. Andreone (Napoli) et al. using magnetron sputtering. High-quality, c-axis-oriented films were obtained on MgO substrates held at about 800^oC during the sputtering process. The best films showed an onset Tc = 15.25 K, a transition width of about 0.3 K, a room temperature resistivity of (55+-3) microohm-cm, a residual resistivity of about 5.5, a low temperature critical current density Jc ~~ 10^5 A/cm^2, and B_[c2] >= 6 T.
Applications
Progress in the fabrication of HTS ac power cables is reported in a preprint by A. Bolza et al. (Pirelli). The authors report the manufacture of a machine-stranded 50 m HTS cable, which carries a dc critical current of 1800 A at 1 mV/cm in liquid nitrogen after repeated rewinding operations. The cable is a prototype for a pipe retrofit HTS 115 kV system being developed under an EPRI/DOE contract (1994-98). The superconducting Bi-2223 tapes were manufactured by American Superconductor Corporation.
Stability parameters (flux-jump and cryogenic stability) for multifilamentary (Bi,Pb)-2223/Ag tapes have been investigated by N. V. Vo (Wollongong) et al. The authors find that these tapes are unlikely to experience any flux-jump instabilities when operated using liquid nitrogen as a coolant. However, improvements in tape processing are needed to increase the normal front velocity to avoid hot-spot formation in the event of a quench.
The design and operation of a high-Tc SQUID gradiometer system that is capable of measuring magnetocardiograms (MCG) in an unshielded environment is reported by N. Tralshawala (TCSUH) et al. The authors report that 1/f flux noise, resulting from the hopping of vortices trapped in the body of a field-cooled high-Tc SQUID, can be eliminated only by zero-field cooling of the SQUID.
A low-loss HTS rf receiver surface probe developed for high-resolution magnetic resonance imaging (MRI) of spinal cord injuries in small animals is described in a preprint by J. Wosik (TCSUH) et al. The HTS coil yields significant signal-to-noise-ratio (SNR) improvements over the use of a conventional copper coil.
Theory
Josephson tunneling from time-reversal-symmetry-breaking states is examined in a preprint by M. B. Walker and J. Luettmer-Strathmann (Toronto). The authors compare the results with those from timereversal-invariant states for both twinned and untwinned crystals, and for both c-axis and basal-plane currents in a model for orthorhombic YBCO. The authors propose and analyze a ring-geometry configuration, which should allow s-wave and d_[x^2-y^2]-wave superconductivity in a tetragonal superconductor to be distinguished on the basis of symmetry arguments alone.
According to a preprint by C. O'Donovan and J. P. Carbotte (McMaster), for a two-layer system in a weak-coupling BCS formalism modeling YBCO, any interlayer interaction, regardless of its sign, enhances the critical temperature. The sign has an effect upon the relative phase of the order parameter in each of the two planes but not upon its magnitude. The authors calculate the magnetic penetration depth, the caxis Josephson tunneling, the density of states, and the Knight shift for several sets of model parameters.
The effect of impurities on the critical temperature for a model of YBCO involving pairing in both the CuO2 planes and CuO chains has been studied by R. Combescot and X. Leyronas (Ecole Normale Superieure). In this model, pairing in the planes is due to phonons, while Coulomb repulsion induces an order parameter with opposite sign in the chains. Because of the anticrossing produced by hybridization between planes and chains, the order parameter changes sign on a single sheet of the Fermi surface, resulting in nodes in the gap. The critical temperature, however, is much less sensitive to impurities than in standard d-wave models.
The temperature dependence of the London penetration depth of isotropic superconductors has been calculated by X. Leyronas and R. Combescot (Ecole Normale Superieure) within strong coupling theory in the clean limit. For a wide range of parameters, the authors find that strongcoupling effects can simulate a power-law dependence, sometimes with excellent precision. Such a temperature dependence is attributed to low-frequency phonons, which serve as quasi-elastic scatterers of electrons.
A preprint by A. A. Abrikosov (Argonne) explains the pseudogap in the caxis optical conductivity of oxygen-deficient YBa2Cu3O6+x in terms of resonant tunneling between CuO2 planes via localized centers in the CuO chains. The conductivity as a function of frequency has a maximum, and its location and magnitude depend only on the spectrum of resonant levels, and hence not on temperature. For fully oxygenated YBCO, the chains are complete, and no resonance centers are formed. The author compares the theory with experiment.
A two-dimensional Fermi liquid coupled to low-energy commensurate spin fluctuations has been examined by A. V. Chubukov (Wisconsin-Madison) et al. At small coupling, the hole Fermi surface is large and centered around (pi,pi). As the coupling increases, the shape of the Fermi surface undergoes substantial evolution, and at strong coupling, the hole Fermi surface consists of small pockets centered at (+-pi/2,+pi/2). At intermediate coupling, there exists a large hole Fermi surface centered at (pi,pi) as well as four hole pockets, but the quasiparticle residue is small everywhere except for the pieces of the pockets that face the Gamma point. The authors discuss the relevance of these results to recent photoemission experiments in YBCO and Bi-2212.
Other Activities
The electronic contribution to the thermal conductivity of a d_[x^2-y^2] superconductor has been calculated by M. Houssa and M. Ausloos (Liege) using a variational method. By accounting for the scattering of electrons by point defects and acoustic phonons, the authors find that the temperature dependence of the thermal conductivity of YBa2Cu3O7-d and Bi2Sr2CaCu2O8+d (Bi-2212) single crystals can be well described with realistic values of the parameters.
Overviews
The fabrication of SQUID magnetometers from epitaxial thin films of high-temperature superconductors and multilayered film structures including perovskite insulator films has been reviewed by A. I. Braginski (KFA-Juelich). The author emphasizes patterning and processing methods, fabrication of Josephson junctions having resistively shunted current-voltage characteristics, attained reproducibility, and spreads of junction critical current and normal resistance. Guidelines are given for designing and fabricating single and multilayered SQUID sensor structures, especially flux transformers and multiloop SQUIDs. Included are correlations with attained performance characteristics of magnetometers: their effective area, white and low-frequency flux noise, and the resulting magnetic field resolution at high and low signal frequencies. The author also describes alternative planar rf SQUID tank-circuit resonators and the resulting properties of rf SQUIDs (139 refs.).
Progress towards the fabrication of Tl-based cuprate high-Tc superconductors for power applications has been reviewed by M. Jergel (Bratislava and Mexico) et al. The authors discuss some basic properties of these materials and then describe two basic approaches to conductor fabrication. Special attention is focused on the fabrication of TlBa2Ca2Cu3O9 (Tl-1223, Tc ~~ 115 K) and Tl2Ba2Ca2Cu3O10 (Tl-2223, Tc ~~ 127 K) (80 refs.)
Contributed by John R. Clem
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.
Researchers at the Oak Ridge National Laboratory have announced the development of a new process for producing substrates for practical superconducting wires with record high critical current density at 77 K. The announcement was made at the MRS Spring Meeting held in San Francisco, California (April 8-12, 1996). The process called RABiTS[TM] (Rolling-Assisted Biaxially Textured Substrates) resulted in a measured critical current density of 2 x 10^6 A/cm^2 in self-field at 77 K. The performance of the YBCO wire in a background magnetic field (compared to Bi powder-in-tube wires) is important for applications in transformers, motors, and generators. In a 1 T field at 77 K, the critical current density was 1.5 x 10^5 A/cm^2, and a high critical current was maintained in fields of up to 5 T.
RABiTS[TM] consists of a base metal tape such as Ni prepared using a special rolling and heat-treatment procedure. A buffer layer is used to provide a chemical barrier between the Ni and the superconductor while maintaining its texture; this is typically a thin layer of Pd deposited using electron beam evaporation or sputtering. Metal-oxide buffer layers, which include cerium oxide and yttria-stabilized zirconia, are then placed on the tapes by pulsed-laser deposition. The YBCO layer is now deposited on this specially prepared RABiTS[TM] substrate. The infield measurements were made across the full sample width (2.3 mm) and length (15 mm). For the 2 x 10^6 A/cm^2 result made in self-field, the researchers made a bridge 200 micrometers wide for the current density measurement. The sample carried a critical current of 4 A in the bridge which, when scaled to the full sample width, extrapolates to over 40 A in the 1-micrometer-thick 2.3-mm-wide YBCO film.
This new result was obtained on a second sample with a different substrate architecture from that of a sample that carried 3 x 10^5 A/cm^2at 77 K, which was announced last week. Standard household wires typically carry less than 1 x 10^3 A/cm^2. Oak Ridge has applied for patents in both the United States and some foreign countries. A nonexclusive license agreement has been signed with Midwest
Superconductivity for use of the technology in research and development, and includes an option for wire and tape commercialization rights. In a planned CRADA, Midwest is partnered with Westinghouse Science and Technology Center and Southwire Company for the development phase of the project with Oak Ridge.
For further information, contact Robert Hawsey, Superconductivity Technology Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6040; telephone (615) 574-6073; telefax (615) 574-6073; e-mail rav@cosmail1.ctd.ornl.gov. Information on the ORNL Superconductivity Program and the RABiTS[TM] development is also available on the Internet at http://www.ornl.gov/HTSC/htsc.html.
Contributed by Sreeparna Mitra
A. A. Abrikosov, "Nature of the 'Pseudogap' in the Optical Conductivity of Oxygen-Deficient YBa2Cu3Ox." Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439. 74.20.Fg; 74.20.Mn; 74.25.Gz; 74.25.Nf; 74.72.Bk.
A. Andreone, M. Iavarone, R. Vaglio, P. Manini, and E. Cogliati, "'InSitu' Growth and Superconducting Properties of YNi2B2C Thin Films." Submitted to Appl. Phys. Lett. Istituto Nazionale per la Fisica della Materia, Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, Piazzale Tecchio 80, I-80125 Napoli, ITALY; e-mail andreone@mvxna2.dsfing.unina.it.
M. M. Asim and S. K. Hasanain, "Modified Flux Flow in Polycrystalline YBCO: Temperature and Current Dependence." To be published in Supercond. Sci. & Technol. Department of Physics, Quaid-I-Azam University, Islamabad 45320, PAKISTAN; telephone and telefax +92 51 829472.
M. Baran and I. Fita, "High Effect of Pressure on the Critical Temperature in GdBa1.5Sr0.5Cu3Ox." To be published in Physica C, Vol. 260 (in press). Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, PL-02-668 Warszawa, POLAND; telefax +48 22430926; e-mail baran@ifpan.edu.pl.
A. Bolza, P. Metra, and M. M. Rahman, "Progress and Issues in HTS Power Cables." Submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Pirelli Cavi SpA, Viale Sarca 222, I-20126 Milano, ITALY; P. Metra's telephone +39 2 6442 3081; telefax +39 2 6442 5502; e-mail metra@drspir.sublink.org.
Ivan Bozovic and J. N. Eckstein, "Atomic-Layer Synthesis of Artifical High-Tc Superconductors and Their Use in Tunnel Junctions." To be published in the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Edward L. Ginzton Research Center, Varian Associates, Inc., 3075 Hansen Way, M/S K-114, Palo Alto, CA 94304-1025; telephone (415) 424-6358; telefax (415) 424-6988; e-mail ivan.bozovic@grc.varian.com.
A. I. Braginski, "Fabrication of High-Temperature SQUID Magnetometers: Correlations with Design and Performance." Institut fuer Schicht- und Ionentechnik (ISI), Forschungszentrum Juelich (KFA), D-52425 Juelich, GERMANY.
C. Bucci, R. de Renzi, G. Guidi, G. Allodi, and F. Licci, "Phase Separation in Antiferromagnetic YBa2Cu3O6+x." Presented at the mu-SR 96 Conf., Nikko, Japan, April 1996; submitted to Hyperfine Interactions. Dipartimento di Fisica and Istituto Nazionale di Fisica della Materia, Universita di Parma, I-43100 Parma, ITALY; telephone +39 521 580222; telefax +39 521 580223; e-mail user@vaxpr.cineca.it.
C. Bucci, R. de Renzi, G. Guidi, C. Bernhard, Ch. Niedermayer, F. Licci, and J. L. Tallon, "mu-SR Measurement of the Superconducting Condensate Reduction Induced by Zn in Underdoped, Optimally Doped and Overdoped YBCO." Presented at the mu-SR 96 Conf., Nikko, Japan, April 1996; submitted to Hyperfine Interactions. Dipartimento di Fisica and Istituto Nazionale di Fisica della Materia, Universita di Parma, I-43100 Parma, ITALY; telephone +39 521 580222; telefax +39 521 580223; e-mail user@vaxpr.cineca.it.
L. N. Bulaevskii, V. M. Vinokur, and M. P. Maley, "Reversible Magnetization of Irradiated High-Tc Superconductors." Submitted to Phys. Rev. Lett. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; email janice_coble@qmgate.anl.gov.
H. Chang, Q. Y. Chen, and W. K. Chu, "Identification of Chemical and Structural Impurities in YBa2Cu3O7-d Films by Raman Spectroscopy." Preprint #94:042; submitted to Physica C. Contact W. K. Chu, Texas Center for Superconductivity, University of Houston, Houston, TX 772045932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu. Key words: Raman spectroscopy, thin film, YBa2Cu3O7-d, Ba2Cu3O5.9, BaCuO2.
X. H. Chen and L. Z. Cao, "Intercalation of Iron Chloride into Bi-Based Superconducting Materials." To be published in Chin. Low Temp. Phys. Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA.
Audrey V. Chubukov, Dirk K. Morr, and Konstantin A. Shakhnovich, "Fermi Surface Evolution in Underdoped Cuprates." Department of Physics, University of Wisconsin, Madison, WI 53706.
R. Combescot and X. Leyronas, "Plane-Chain Coupling in YBa2Cu3O7: Impurity Effect on the Critical Temperature." Laboratoire de Physique Statistique, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris Cedex 05, FRANCE; e-mail roland.combescot@tournesol.ens.fr; preprint also available at cond-mat@xxx.lanl.gov (#9603131). 74.20.Fg; 74.72.Bk; 74.25.Jb.
G. W. Crabtree, G. K. Leaf, H. G. Kaper, D. W. Braun, V. M. Vinokur, and A. E. Koshelev, "Dynamic Vortex Phases in Superconductors with Correlated Disorder." Submitted to Phys. Rev. Lett., March 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.
X. T. Cui, Z. H. Zhang, Q. Y. Chen, J. R. Liu, and W. K. Chu, "Ion Channeling Studies in YBCO Thin Film at Low Temperature." Preprint #96:027; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
Jeffrey P. Emerson, Daniel A. Wright, Robert A. Fisher, and Norman E. Phillips, "Effect of Oxygen Content on the Specific Heat and Magnetic Susceptibility of YBa2Cu3O7-d." Submitted to the XXI Int. Conf. on Low Temperature Physics (LT 21), Prague, Czech Republic, Aug. 8-14, 1996. Contact R. A. Fisher, Low Temperature Laboratory, University of California, Berkeley, CA 94720.
T. Endo, J. Santamaria, A. Hoffmann, and Ivan K. Schuller, "Persistent Photoconductivity Spectrum of GdBa2Cu3O6.3 in the IR to UV Region." To be published in the Proc. of the XXI Int. Conf. on Low Temperature Physics (LT 21), Prague, Czech Republic, Aug. 8-14, 1996. Contact A. Hoffmann, Department of Physics 0350, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0350; telephone (619) 5347161; telefax (619) 534-0173; e-mail hoffmann@ucsd.edu.
D. M. Frenkel and J. A. Clayhold, "Current Instabilities in Reentrant Superconductors." Preprint #96:037; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
A. K. Gangopadhyay and J. S. Schilling, "Change of Density of States at Fermi-Level and Superconductivity in YNi2-x(Co/Cu)xB2C." Submitted to Physica C. Department of Physics, Washington University, Campus Box 1105, One Brookings Dr., St. Louis, MO 63130-4899; e-mail anup@howdy.wustl.edu. Key words: borocarbide superconductors, Pauli susceptibility, density of states.
J. Geny, J. K. Meen, and D. Elthon, "Effect of Pressure on La2O3-CuO Subsolidus Phase Equilibria." Preprint #96:031; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
Laura Gherardi, Paola Caracina, Giacomo Coletta, and Sergio Spreafico, "Critical Current Versus Field Behavior in Ag/BSCCO-2223 Tapes with Different Critical Currents." To be published in Mater. Sci. Eng. B (in press). Pirelli Cavi SpA, Viale Sarca 222, I-20126 Milano, ITALY. Key words: magnetic fields, high-temperature superconductors, BSCCO tapes.
J.-C. Grivel and R. Fluekiger, "Visualization of the Formation of the (Bi,Pb)2Sr2Ca2Cu3O10+d Phase." To be published in Supercond. Sci. & Technol. Departement de Physique de la Matiere Condensee, Universite de Geneve, 24 quai Ernest-Ansermet, CH-1211 Geneve 4, SWITZERLAND; telephone +41 22 702 61 11; telefax +41 22 702 68 69; e-mail grivel@sc2a.unige.ch. 74.72.Hs; 82.30.-b.
O. Gunnarsson, V. Eyert, M. Knupfer, J. Fink, and J. F. Armbruster, "Plasmon Dispersion in A3C60 (A=K, Rb)." To be published in J. Phys. Max-Planck-Institute fuer Festkoerperforschung, Postfach 80 06 65, D70506 Stuttgart, GERMANY; e-mail gunnar@radix3.mpi-stuttgart.mpg.de.
V. Hardy, A. Wahl, S. Hebert, A. Ruyter, J. Provost, D. Groult, and Ch. Simon, "Accommodation of Vortices to Tilted Line Defects in High Tc Superconductors with Various Electronic Anisotropies." To be published in Phys. Rev. B. Laboratoire CRISMAT-CNRS, URA 1318, ISMRA, Universite de Caen, Boulevard du Marechal Juin, 14050 Caen Cedex, FRANCE.
M. Houssa and M. Ausloos, "Evidence of d-Wave Pairing in the Thermal Conductivity of YBa2Cu3O7-d and Bi2Sr2CaCu2O8 Single Crystals." To be published in Z. Phys. B. SUPRAS, Institut de Physique B5, Universite de Liege, B-4000 Liege, BELGIUM. 74.25.Fy; 74.72.Bk; 74.72.Hs.
C. R. Hu, "Zero-Bias Conductance Peak as a Result of Midgap Interference States - A Model Study." Preprint #96:023; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
F. Ichikawa, Y. Yamasaki, T. Nishizaki, T. Fukami, T. Aomine, S. Kubo, and M. Suzuki, "Magnetoresistance in a Nd2-xCexCuO4 Thin Film Below Tc." To be published in Solid State Commun., Vol. 98, No. 2 (1996). Department of Physics, Faculty of Science, Kyushu University, Fukuoka 812-81, JAPAN. Key words: high-Tc superconductors, thin films, electronic states (localized), phase transitions.
Sumio Ikegawa and Yuichi Motoi, "Growth of CeO2 Thin Films by Metalorganic Molecular-Beam Epitaxy." To be published in Thin Solid Films (1996): Proc. of the 13th Int. Vacuum Congress/9th Int. Conf. on Solid Surfaces, Yokohama, Japan, Sept. 25-29, 1995. Advanced Research Laboratory, Toshiba Corporation, 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki 210, JAPAN; telephone +81 44 549 2295; telefax +81 44 520 1801; e-mail 000091100037@tg-mail.toshiba.co.jp.
Sumio Ikegawa and Yuichi Motoi, "MBE Growth of a Layered Cuprate Having a Multiple Fluorite-Type Block for Use in Trilayer Junctions." To be published in Appl. Phys. Lett. (in press). Advanced Research Laboratory, Toshiba Corporation, 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki 210, JAPAN; telephone +81 44 549 2295; telefax +81 44 520 1801; e-mail 000091100037@tg-mail.toshiba.co.jp. 68.55.Bd; 61.10.-i; 61.14.Hg; 74.80.Dm.
M. Jergel, A. Conde Gallardo, C. Falcony Guajardo, and V. Strbik, "TIbased Superconductors for High-Current, High-Field Applications." Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Apdo. Postal 14-740, Mexico D. F., MEXICO; telephone +52 5 754 02 00; telefax +52 5 586 65 64; e-mail mjergel@fis.cinvestav.mx. 74.72.Fq; 74.76.Bz.
M.-H. Julien, P. Carretta, M. Horvatic, C. Berthier, Y. Berthier, P. Segransan, A. Carrington, and D. Colson, "Spin Gap in HgBa2Ca2Cu3O8+d Single Crystals from [63]^Cu NMR." Submitted to Phys. Rev. Lett. Grenoble High Magnetic Field Laboratory, Centre National de la Recherche Scientifique and Max-Planck-Institut fuer Festkoerperforschung, Boite Postale 166, F-38042 Grenoble Cedex 9, FRANCE; telefax +33 76 85 56 10; e-mail mjulien@labs.polycnrs-gre.fr. 74.25.Nf; 74.72.Jt; 76.60.-k.
W. D. Lee, J. L. Chen, T. J. Yang, and Bi-Shiou Chiou, "Influence of an External Electric Field on High-Tc Superconductivity." To be published in Physica C, Vol. 260 (in press). Contact J. L. Chen, Department of Electro-Physics, National Chiao-Tung University, Hsinchu, TAIWAN; telefax +886 35 725 230.
F. Legendre, L. Schmirgeld-Mignot, P. Regnier, H. Safar, J. Y. Coulter, and M. Maley, "Transport Critical Currents of Bi2212 Tapes Prepared by Sequential Electrolytic Deposition." Submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Section de Recherches de Metallurgie Physique, DECM, C.E.A. Saclay, F-91191 Gif Sur Yvette Cedex, FRANCE; L. Schmirgeld-Mignot's telephone +33 1 69 08 20 68; telefax +33 1 69 08 68 67; e-mail lelia@srmp04.saclay.cea.fr.
X. Leyronas and R. Combescot, "The London Penetration Depth of Strongly Coupled Isotropic Superconductors: Low Temperature Behavior." To be published in Phys. Rev. B. Laboratoire de Physique Statistique, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris Cedex 05, FRANCE; R. Combescot's e-mail roland.combescot@tournesol.ens.fr; preprint also available at cond-mat@xxx.lanl.gov (#9603040). 74.20.Fg; 74.72.Bk; 74.25.Jb.
A. I. Liechtenstein, O. Gunnarsson, M. Knupfer, J. Fink, and J. F. Armbruster, "Plasmon Damping and Response Function in Doped C60 Compounds." To be published in J. Phys. Max-Planck-Institute fuer Festkoerperforschung, Postfach 80 06 65, D-70506 Stuttgart, GERMANY.
J. T. Lin, Z. G. Zou, J. H. Miller, Jr., and Q. Xiong, "Use of Cuprate Tricrystal Microbridges as Probes of Superconducting Pairing State Symmetry." Preprint #96:034; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
J. Lopez and P. Mune, "Anomalous Inversion of Voltage Versus Current Curves in ZFC and FC Conditions in BSCCO Ceramic Superconductors." To be published in Physica C, Vol. 260 (in press). Superconductivity Laboratory, IMRE, Faculty of Physics, University of Havana, 10400 Havana, CUBA.
H. M. Luo, Z. X. Zhao, G. C. Che, F. Wu, H. Chen, C. Dong, Z. Y. Chen, and Y. T. Qian, "Synthesis and Crystal Structure of New Pb-Based Copper Oxides (Pb0.5M0.5)(Sr0.9Ho0.1)2(Ho0.7Ce0.3)2Cu2Oy (M=Pb and Cd)." To be published in J. Solid State Chem. Department of Applied Chemistry, University of Science & Technology of China, Hefei, Auhui 230026, PEOPLE'S REPUBLIC OF CHINA.
Peter Majewski, Stefanie Kaesche, and Fritz Aldinger, "Fundamentals on the Preparation of HTc Superconducting (Bi,Pb)2+xSr2Ca2Cu3O10+d Ceramics." Submitted to Adv. Mater. Pulvermetallurgisches Laboratorium, Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 5, D-70569 Stuttgart, GERMANY.
Hideki Matsumoto, Taiichiro Saikawa, and Ferdinando Mancini, "Temperature Dependence of Electronic States in the t-J Model." Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980, JAPAN; e-mail matumoto@tacsun.imr.tohoku.ac.jp.
John T. McDevitt, Chad A. Mirkin, Rung-Kuang Lo, Kaimin Chen, Ji-Ping Zhou, Feng Xu, Steven G. Haupt, Jianai Zhao, and David C. Jurbergs, "Molecular Level Control over the Surface and Interfacial Properties of High-Tc Superconductors." To be published in Chem. Mater. Department of Chemistry, The University of Texas at Austin, Austin, TX 78712-1167; telephone (512) 471-0046; telefax (512) 471-8696; e-mail mcdevitt@huckel.cm.utexas.edu.
J. K. Meen and D. Elthon, "Melting Relations in Bi2O3-CuO-Cu2O." Preprint #96:030; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
M. K. Mironova, G. Du, S. Sathyamurthy, I. A. Rusakova, and K. Salama, "TEM Study of Low-Angle Grain Boundaries in Polycrystalline YBCO." Preprint #96:026; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
G. C. Montanari, I. Ghinello, L. Gherardi, and P. Caracino, "Characterization of Monofilamentary and Multifilamentary 2223-BSCCO Tapes by Magnetic Loss Measurements." 1st. Elettrotecnica Industriale, Universita di Bologna, Bologna, Viale Risorgimento 2, I-40136 Bologna, ITALY.
V. A. Murashov, P. Schaetzle, G. Krabbes, J. Klosowski, H. Wendrock, H. R. Vogel, and K. Eversmann, "Influence of the Y2BaCuO5 Particle Size Distribution on the Crack Propagation and the Trapped Magnetic Flux in Melt Textured YBCO." To be published in Physica C. Contact P. Schaetzle, Institut fuer Festkoerper- und Werkstofforschung Dresden e. V., Postfach 270016, D-01171 Dresden, GERMANY; telephone +49 351 2582225; telefax +49 351 2582 314. Key words: 211 particle, melt texturing, crack propagation, trapped magnetic flux.
Anh Kiet Nguyen, A. Sudbo, and R. E. Hetzel, "Vortex-Loop Unbinding and Flux-Line Lattice Melting in Superconductors." Department of Physics, Norwegian University of Science and Technology, N-7034 Trondheim, NORWAY. 74.60.-w; 74.60.Ge.
C. O'Donovan and J. P. Carbotte, "Effects of Interlayer Interaction on the Superconducting State in YBCO." Department of Physics & Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, CANADA; preprint also available at cond-mat@xxx.lanl.gov (#9604049).
M. R. Palacin, N. Casan-Pastor, G. Kraemer, M. Jansen, and P. GomezRomero, "Cationic Substitutions and Doping in the Series of Layered Perovskites Ln2Ba2Cu2Ti2O11 (Ln=La, Nd, Eu, Tb)." To be published in Physica C (in press). Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, 08193 Bellaterra, Barcelona, SPAIN; telefax +34 3 580 5729. Keywords: copper-titanium oxides, layered perovskites, doping, high pressure.
Dhananjai Pandey, S.S.R. Inbanathan, P. K. Srivastava, Alok Banerjee, and G. Singh, "Towards the Rapid Synthesis of Pure 2223 Powders with Bi2-xPbxSr2Ca2Cu3Oy Compositions by Semi-Wet Methods: III. Role of Sintering Temperature and Duration." To be published in Physica C, Vol. 260 (in press). School of Materials Science and Technology, Banaras Hindu University, Varanasi 221 005, INDIA.
C. Paracchini, L. Romano, C. A. Borri, and M. Affronte, "Resistivity Measurements in Superconducting Ba1-xKxBiO3." To be published in Physica C (in press). Dipartimento di Fisica, Universita di Parma, Parma I-43100, ITALY; telefax +39 521 905223. 74.25.Fy; 74.60.Ge.
J. A. Parrell, A. A. Polyanskii, A. E. Pashitski, and D. C. Larbalestier, "Direct Evidence for Residual, Preferentially Oriented Cracks in Rolled and Pressed Ag-Clad BSCCO-2223 Tapes and Their Effect on the Critical Current Density." To be published in Supercond. Sci. & Technol., May 1996. Applied Superconductivity Center, University of Wisconsin at Madison, 1500 Engineering Drive, Madison, WI 53706-1687; A. A. Polyanskii's e-mail polyansk@coefac.engr.wisc.edu.
V. Rouessac, J. Wang, J. Provost, and G. Desgardin, "Rapid Synthesis of the Bi(Pb)-2223 110 K Superconductor by EDTA Sol-Gel Method." To be published in J. Mater. Sci. Laboratoire CRISMAT, ISMRA, 6 Bd. du Marechal Juin, 14050 Caen Cedex, FRANCE. Keywords: superconductor, B(P)SCCO 110 K-Tc phase, EDTA sol-gel synthesis method.
I. A. Rusakova, R. L. Meng, P. Gautier-Picard, and C. W. Chu, "Microstructural Changes of YBCO Induced by Lanthanide Doping." Preprint #96:020; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
K. Salama, A. S. Parikh, P. Putman, and L. Woolf, "A Novel Approach to High Rate Melt-Texturing in 123 Superconductors." Preprint #96:032; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). 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.
S. Salib, M. K. Mironova, and C. Vipulanandan, "Role of Constituents on Composite BPSCCO Tapes." Preprint #96:019; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
F. Sandiumenge, N. Vilalta, X. Obradors, S. Pinol, J. Bassas, and Y. Maniette, "Polygonization of Directionally Solidified High Critical Current YBa2Cu3O6+x." To be published in J. Appl. Phys., Vol. 79, No. 10, May 15, 1996. Institut de Ciencia de Materials de Barcelona, C.S.I.C., Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalunya, SPAIN; telephone +34 3 580 18 53; telefax +34 3 580 57 29; e-mail felip@icmab.es.
J. S. Schoen and S. S. Wang, "Partial-Melt Processing of Bulk MgOWhisker Reinforced (Bi,Pb)2Sr2Ca2Cu3O10-x Superconductor." Preprint #96:022; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
J. E. Sonier, R. F. Kiefl, J. H. Brewer, D. A. Bonn, S. R. Dunsiger, W. N. Hardy, Ruixing Liang, W. A. MacFarlane, and T. M. Riseman, "Magnetic Field Dependence of the London Penetration Depth in the Vortex State of YBa2Cu3O6.95." Submitted to Phys. Rev. Lett. Department of Physics, University of British Columbia, Vancouver, British Columbia V6T 1Z1, CANADA; telefax (604) 822-5324; e-mail sonier@triumf.ca. 74.25.Ha; 74.72.Bk; 76.75.+i.
N. Tralshawala, J. R. Claycomb, Q. Ying, J. H. Miller, Jr., K. Nesteruk, and D. R. Jackson, "High-Tc SQUID Gradiometers for Magnetocardiography in an Unshielded Environment." Preprint #96:041; submitted to the Proc. of the 10th Int. Conf. on Biomagnetism (BioMag 96), Santa Fe, NM, Feb. 16-21, 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.
N. Vandewalle, M. Ausloos, N. Mineur, and R. Cloots, "Fractal Grain Boundaries in Composite YBa2Cu3O7-d/Y2O3 Resulting from a Competition Between Growing Grains: Experiments and Simulations." Presented at the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). S.U.P.R.A.S., Institut de Physique B5, Universite de Liege, B-4000 Liege, BELGIUM; email vandewal@gw.unipc.ulg.ac.be.
N. V. Vo, H. K. Liu, S. X. Dou, and I. Kusevic, "Conductor Design with High-Tc Superconducting Bi(Pb)-2223/Ag Multifilamentary Tapes." Submitted to Mater. Sci. Eng. Centre for Superconducting and Electronic Materials, Institute of Materials Technology and Manufacturing, University of Wollongong, Northfields Ave., Wollongong, NSW 2522, AUSTRALIA.
M. B. Walker and J. Luettmer-Strathmann, "Josephson Tunneling in High-Tc Superconductors." To be published in Phys. Rev. B. Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7, CANADA; J. Luettmer-Strathmann's telephone (416) 978-5207; telefax (416) 978-2537; e-mail jutta@physics.utoronto.ca; preprint also available at cond-mat@xxx.lanl.gov (#9604009). 74.20.De; 74.50.+r; 74.72.Bk 74.62.Bf.
Z. Y. Weng, D. N. Sheng, and C. S. Ting, "Phase String, Superconductivity, and Spin Dynamics in the t-J Model." Preprint #96:036; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
K. Widder, M. Merz, D. Berner, J. Muenzel, H. P. Geserich, A. Erb, R. Fluekiger, W. Widder, and H. F. Braun, "Optical Investigation of Y1zPrzBa2Cu3O7-d Single-Domain Crystals: A Comparision Between ImpurityFree and Al-Doped Samples." Institut fuer Festkoerperforschung, IFW Dresden e.V., Postfach 210016, D-01171 Dresden, GERMANY. 74.25.Gz; 74.72.Bk; 74.72.Jt.
P. Wochner, E. Isaacs, S. C. Moss, P. Zschack, J. Giapintzakis, and D. M. Ginsberg, "X-ray Search for CDW in Single Crystal YBa2Cu3O7-d." Preprint #96:029; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Contact Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
J. Wosik, K. Nesteruk, L. M. Xie, X. P. Zhang, P. Gierlowski, C. Jiao, and J. H. Miller, Jr., "High-Tc Superconducting rf Receiver Coils for High Resolution Magnetic Resonance Imaging of the Spine." Preprint #96:038; submitted to the Proc. of the 10th Int. Conf. on Biomagnetism (BioMag 96), Santa Fe, NM, Feb. 16-21, 1996. Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
Z. Xia, K. B. Ma, R. S. Cooley, P. C. Fowler, and W. K. Chu, "Superconducting Magnetic Bearing and its Applications in Flywheel Kinetic Energy Storage." Preprint #96:035; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
Q. Xiong, S. Afonso, F. T. Chan, K. Y. Chen, G. J. Salamo, G. Florence, J. Cooksey, S. Scott, S. Ang, W. D. Brown, and L. Schaper, "Fabrication of Highly Textured Superconducting Thin Films on Polycrystalline Substrates Using Ion Beam Assisted Deposition." Preprint #96:017; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Contact Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
X. Z. Xiong, P. Wochner, and S. C. Moss, "In-Plane Ordering in PhaseSeparated and Staged Single Crystal La2CuO4-d." Preprint #96:028; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). 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.
J. H. Xu, Y. Ren, and C. S. Ting, "s+d Pairing Symmetry and Vortex Structures in YBCO." Preprint #96:040; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
G. Yang and C. Vipulanandan, "Properties of Jointed BPSCCO Composites." Preprint #96:024; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
G. Z. Zhang, M. S. Wong, and S. S. Wang, "Strain Tolerance of Superconducting Properties and Cryogenic Mechanical Behavior of Bulk MgO-Whisker-Reinforced HTS BPSCCO Composite." Preprint #96:021; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). 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.
X. J. Zhou, M. Cardona, C. W. Chu, Q. M. Lin, S. M. Loureiro, and M. Marezio, "Raman Study of HgBa2Can-1CunO2n+2+d (n=1,2,3,4 and 5) Superconductors." Preprint #96:025; submitted to the Proc. of the 10th Anniv. HTS Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Contact Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu.
*June 25 - 27, 1996: 9th International Cryocooler Conference (ICC9), Waterville Valley, NH. Technical program will consist of oral and poster sessions. Invited technical topics include Stirling and pulsetube cryocoolers, J-T and sorption cryocoolers, G-M and TEC cryocoolers, new concepts, component developments, modeling and test techniques, performance and life test data, applications and integration issues, and low-cost coolers. Pre-registration deadline, May 27, 1996. For information, contact Walter Swift, ICC9, Creare Inc., P.O. Box 71, Hanover, NH 03755; telephone (603) 643-3800; telefax (603) 643-4657; email wls@creare.com. Additional information about Waterville Valley and other New Hampshire attractions can be found at the URLs http://www.waterville.com or http://www.cyberspy.com/~webster/nh.html.
*July 13 - 20, 1996: 2nd International Summer School on High Temperature Superconductivity, Eger, Hungary. Organized by the Hungarian Chapter of Superconductivity Society. Will cover a wide range of topics in high-Tc superconductors from basic theories to engineering applications. Main aim is to give a comprehensive and updated knowledge to Ph.D. students and research scientists already involved in HTS work. Lectures to be given by outstanding scientists in the field. The following topics will be included: ten years of high-Tc superconductivity, survey of theories on high-Tc superconductivity, physical properties of HTS materials, characterization and measurements of the physical properties, new trends in preparation techniques, crystal structure of HTS materials, interdependence of the physical properties and morphology, manufacturing of HTS conductors, and smalland large-scale applications. Language of the Summer School is English. Papers to be published. For information, contact Istvan Vajda, Dept. of Electrical Machines and Drives, Technical University of Budapest, Egry Jozsef utca 18., H-111 Budapest, Hungary; telephone +36 1 463-2961; telefax +36 1 463-3600; e-mail vajda@ntb.bme.hu.
*July 21 - 27, 1996: NATO Advanced Research Workshop on Physics and Materials Science of High Temperature Superconductivity IV, Patria Hotel, Strbske Pleso, High Tatry Mountains, Slovak Republic. Workshop limited to 60 participants. Send inquiries to Dr. Ram Kossowsky, ETI, 6327 Burchfield Ave., Pittsburgh, PA 15217; telephone (412) 421-4408; telefax (412) 421 4342; e-mail ramkoss@ netcom.com or wk02025@worldlink.com.
Dec. 2 - 6, 1996: MRS Fall Meeting: Symposium GG -- High-Temperature Superconductivity - Interplay of Fundamentals and Applications. This symposium will focus on two general problems of interest to both fundamental research and commercial applications: (1) critical currents in bulk high-temperature superconductor materials, and (2) superconductor interfaces in thin-film materials. Goal is also to foster interactions between researchers concerned with problems from both perspectives. Original experimental and theoretical papers in the following topics are requested: vortex structure, pinning, and dynamics; critical currents; wire and tape processing and properties; thin-film growth; heterostructures and interfaces; devices; and applications. Abstract deadline, June 21, 1996. Contact one of the symposium organizers: Charles M. Lieber, Department of Chemistry, Harvard University, 12 Oxford Street, Cambridge, MA 02138; telephone (617) 496-3169; telefax (617) 496-5442 or -6731; e-mail cml@cmliris.harvard.edu; or Ivan Bozovic, MS K-114, Edward Ginzton Research Center, Varian Associates, Inc., 3075 Hansen Way, Palo Alto, CA 94304-1025; telephone (415) 424-6358; telefax (415) 424-6988; e-mail ivan.bozovic@grc.varian.com. Information also available at the MRS homepage http://www.mrs.org.
Dec. 16 - 21, 1996: International Workshop on High-Temperature Superconductivity: Ten Years After its Discovery, Jaipur, India. Organized by Drexel University, Philadelphia, and University of Rajasthan, Jaipur, and sponsored by the U.S. National Science Foundation. The primary purpose is to bring researchers from India and other countries together to discuss latest developments, to promote dialogue among different groups, and to encourage cooperative activities and international collaborations. The second objective is promotion of science and engineering education focused on the needs of young researchers in the field. Lectures and discussions to be presented by prominent scientists from the U.S. and other countries. Space limitation may restrict number of participants. For further information, contact Workshop Chairs: S.M. Bose, Department of Physics and Atmospheric Science, Drexel University, Philadelphia, PA 19104; telephone (215) 895-1706; telefax (215) 895-4999; e-mail bose@duvm.ocs.drexel.edu; or K.B. Garg, Department of Physics, University of Rajasthan, Jaipur, India; telephone and telefax +91-141511912; e-mail cmpl@sirnetd.ernet.in.
Feb. 23 - 25, 1997: 1997 International Symposium on Intrinsic Josephson Effect and THz Plasma Collisions in High Tc Superconductors, Institute of Materials Research, Tohoku University, Sendai, Japan. Topics will include cuprate superconductors, single crystals, high-quality thin films, anisotropic electronic and magnetic properties, vortex flow in layered structures, high-frequency plasma oscillations, far-infrared properties, and high-frequency electronic devices. Invited, oral, and poster contributions. Abstract deadline, November 15, 1996. Official language is English. For further information, contact Kensuke Makajima or Sergei E. Shafranjuk, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980, Japan; telephone +81 22 217-5472 or -5476; telefax +81 22 217-5473; e-mail knaka@riec.tohoku.ac.jp or sergei@riec.tohoku.ac.jp.
*Feb. 28 - March 4, 1997: Fifth International Conference on Materials and Mechanisms of Superconductivity and High-Temperature Superconductors (M^2S-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 1, 1996. For information, contact D. Jin, M^2S-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.
*March 6 - 8, 1997: International Workshop of Crystal Chemistry of High-Tc Superconductors (CC-HTSC'97), Hefei, China. Satellite conference to the Fifth International Conference on Materials and Mechanisms of Superconductivity (M^2S-HTSC-V) at Beijing. Crystal chemistry, structure, as well as other related topics on high-Tc superconductors. (Submitted papers should not have been presented at the M^2S-HTSC-V Conf. in Beijing). Main topics are new superconductors and their crystal structures, microstructures and modulated structures, crystal growth and structure determination, electronic structures, chemical bonding in superconductors, phase diagram, crystal structure of fullerenes, intermetallic-compound superconductors, and other related materials. Conference language is English. Further details to be announced in second circular. For further information, contact LI XiaoGuang, CC-HTSC'97 Conference Secretary, Structure Research Laboratory, University of Science and Technology of China, Hefei, China; e-mail lixg@email.sc.ustc.ac.cn.
Information
The World Materials Calendar, published quarterly, contains details of approximately a thousand materials-related events (conferences, exhibitions, meetings, and courses), and includes listings up to Sept. 2003. Events listed in chronological order with new and amended entries. Comprehensive indexes for location, sponsor, and subject included in each issue. Other information included in entries are abstract submission deadlines, actual venue, prices for attendance, and availability of proceedings volumes. To order a copy or receive further information, contact Debbie Barthelmes, Materials Information, ASM International, Materials Park, OH 44073-0002; telephone (216) 338-5151; telefax (216) 338-8091. In Europe contact Julie Lee, Materials Information, The Institute of Materials, 1 Carlton House Terrace, London SWIY 5DB, UK; telephone +44 171 839-4071; telefax +44 171 839-2289.
New Book: Driving Force: The Natural Magic of Magnets, by James D. Livingston. Book is written to inform and entertain both technical and non-technical readers and will give a clearer sense of the force behind so much of the working world. Unfolds the long and colorful history of magnets and includes a chapter devoted to superconductors and superconducting magnets. Several applications of superconducting magnets, including MRI and magnetic levitation, are discussed. Publ. 1996; 320 pp.; price $24.95; ISBN 0-674-21644-X. Contact Harvard University Press, 79 Garden Street, Cambridge, MA 02138; telephone (800) 448-2242 or (617) 495-2480; telefax (800) 962-4983 or (617) 495-5898; email jco@hup.mhs.harvard.edu.
New MRS Publication: Epitaxial Oxide Thin Films II, edited by James S. Speck, David K. Fork, Ronald W. Wolf, and Tadashi Shiosaki. Vol. 401 in the MRS Symposium Proceedings Series, documents reports from the 1995 MRS Fall Meeting in Boston. Features recent technical information on the subject from industry, academia, and government laboratories. Discusses present understanding and control of epitaxial heterostructures along multiple frontiers including magnetic, dielectric, ferroelectric, and superconducting oxide materials. Includes 77 papers. Publ. 1996; 562 pp.; price $64 (members), $70 (US List), $75 (non-US List); ISBN 1-55899-304-5. Contact the Materials Research Society, Customer Service Dept., 9800 McKnight Road, Pittsburgh, PA 15237-6006; telephone (412) 367-3012; telefax (412) 3674373.
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, #9, May 1, 1996.