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, NSF, and other agencies, organizations, and individuals.

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PLEASE NOTE: Issues of High-Tc Update from November 15, 1993, onward are also available in coded Word versions (BINHEX and RTF). (These versions preserve the Greek letters, special characters, accents, etc.) If you are interested in the alternate formats, contact the editor for information.

PLEASE READ: The electronic-mail version of High-Tc Update is generated from a Macintosh Microsoft Word file and turned into a text file that can be transferred electronically. Formatting commands, Greek symbols, diacritical marks, etc. are lost in this transformation. In order to improve the readability of the e-mail version, the newsletter staff add explanatory marks as needed to the text file. For example, a carat (10^5) indicates a superscript (ten to the fifth). A carat followed by a bracket (cm^[-2]) indicates everything within the brackets is superscripted (centimeter to the minus 2). A bracket followed by a carat ([18]^O) indicates everything before the carat is superscripted. An underline (M_i) indicates a subscript (M subscript i). Most Greek letters are spelled out (Delta, mu, tau, pi, Omega), although delta is left as "d." In most instances, easily recognizable formulas or units are left as they appear: Tc, Jc, YBa2Cu3O7, O2. Mu-m is changed to micrometers. Diacritical marks (accents, tildes, carats, etc.) are removed, but the German umlaut (e.g., a, o, or u with two dots over it) is changed into a, o, or u followed by e. If needed for clarity, hyphens are occasionally inserted between spelled-out Greek letters or symbols (ohm-cm, sin-theta).

NOTA BENE: With this issue we introduce a new column in the newsletter called Cryo Applications. This column, which debuts with encouragement and help from Dr. Frank Patten (ARPA), will feature invited articles that discuss novel cryoengineering applications currently being developed within the cryogenic industry. As cryoengineering is an enabling technology critical to the long-term success of several HTS superconductivity applications, we believe this column will be a valuable forum for those working in application-oriented fields. Our debut article is written by John Ramsden and Randy Simon from Conductus, Inc. Please see page 6.

This NOTA BENE is contributed by Sreeparna Mitra, Editor and Project Director of High-Tc Update. The author would like to thank D. K. Finnemore, Professor of Physics at Iowa State University, for technical help. Our Science Editor, John R. Clem, is currently on travel.

Buckley Prize

The 1998 Oliver E. Buckley Condensed Matter Physics Prize was awarded to Dale J. van Harlingen (U. Illinois), Donald M. Ginsberg (U. Illinois), John R. Kirtley (IBM TJW Research Center), and Chang-Chyi Tsuei (IBM TJW Research Center) for using phase-sensitive experiments in the elucidation of the orbital symmetry of the pairing function in high-Tc superconductors.

YBCO

Femtosecond time-resolved optical spectroscopy is used by D. Mihailovic (Jozef Stefan Inst.) et al. to investigate quasiparticle dynamics in YBCO. In the underdoped state, the data suggest pair formation with an associated redistribution of the density of states (DOS) starting at a temperature T* above Tc, and the establishment of phase coherence at Tc consistent with Bose-Einstein condensation. In the optimally doped materials, both a divergence in lifetime and a change of the DOS occur at Tc signifying that opening of a gap and occurrence of pairing takes place simultaneously.

Results from c-axis Josephson tunneling experiments are reported by K. A. Kouznetsov (Berkeley) et al. in which a conventional superconductor (Pb) is deposited across a single twin boundary of YBa2Cu3O7-d crystals. The authors measure the critical current as a function of the magnitude and angle of the magnetic field applied in the plane of the junction and observe a clear signal of an order parameter shift across the twin boundary, providing strong evidence for a mixed d- and s-wave pairing in YBCO with a reversal in the sign of the s-wave component across the twin boundary.

A macroscopic change in the shape of five-domain melt-processed YBa2Cu3Ox-Y2BaCuO5 bulk superconductors is reported in a paper by P. Diko (Slovak Academy) and K. C. Goretta (Argonne). The authors observe a distortion from the circular cross section in the material and attribute this to liquid transport from a slower growth front in an a- axis direction to a faster growth front in a c-axis direction at the edge of the a and c growth fronts, a phenomenon they refer to as the edge-melt effect (EMD). Formation of bands of higher Y2BaCuO5 particle density along the a/c growth boundaries is explained by this EMD effect.

High-temperature deformation experiments were performed on melt-textured YBCO specimens by M. Ullrich (Goettingen) et al. by applying strain rates from 1 x 10^[-5] s^[-1] to 5 x 10^[-4] s^[-1] under flowing oxygen in the temperature range 850^oC to 950^oC. The authors conclude that the predominant deformation mechanism is a dislocation glide and climb governed by climb at Y-211 particles. The authors expect an improvement in mechanical properties by introducing a bimodal Y-211 distribution.

Bi Cuprates

Thin whiskers of orthorhombic Bi2Sr2CaCu2Ox have been grown from powders by A. E. Curzon et al. (Simon Fraser) and their resistive transitions studied at constant current. Results show a sudden increase in the potential difference between the voltage electrodes of some whiskers. The authors theoretically explain this increase by one or more intercalated layers of Bi2Sr2Ca2Cu3Ox inside the bulk Bi2Sr2CaCu2Ox material.

A preprint by A. M. Ghorayeb (MATOP) et al. reports resistivity studies on iodine-intercalated single crystals of Bi2Sr2CaCu2O8 as a function of T (between 10 K and 300 K) and magnetic field (up to 15 T). Measurements for both rho_[ab] and rho_c along H||ab and H||c show that the metallic character along the c axis observed in the normal state of intercalated samples is maintained when a magnetic field is applied, confirming that a reduction in the anisotropy accompanies the intercalation process. In the superconducting state, the magnetic field causes broadening of the superconducting transition (as it does in the non-intercalated materials), especially for H||c, indicating that the superconducting state retains its anisotropic character after intercalation. The authors use resistivity data in the flux-flow regime to estimate values of the activation energy for vortex movement.

Other Cuprates

Non-equilibrium superconductivity of DyBa2Cu3O7-d is studied in a paper by B. J. Feenstra (Groningen) et al. using photoinduced activation of mm-wave absorption (PIAMA). The authors monitored the time evolution of the thin-film transmissivity subject to pulsed infrared radiation and observe, in addition to a positive bolometric signal, a second faster decay with a sign opposite to the bolometric signal at T > 40 K. The authors attribute this effect to properties of quasiparticles residing near the nodes of an unconventional superconductor resulting in a strong enhancement of the recombination rate.

High quality NdBaCuO melt-textured grains with Tc = 95.7 K, Jc > 60 kA/cm^2 (0 T,77 K), and B_[irr] > 8 T have been prepared via an isothermal route by W. Bieger et al. (Dresden). The technique allows for good stoichiometric control during the process by using an appropriate admixture, a suitable limited oxygen supply, and low temperature.

Significantly greater low-temperature flux pining is achieved by V. Badri et al. (Colorado) by substitution of bismuth into the TlBa2Ca2Cu3O9 system. The authors attribute this higher pinning to increased coupling between the CuO2 planes along the c axis.

Films on YSZ

A paper by P. N. Arendt et al. (Los Alamos) presents a coating system for the deposition of in-plane-oriented YSZ template films on 1 cm wide flexible metal substrates that, in the static mode, can produce template films on 20 cm substrate lengths, and in the continuous coating mode, can produce good quality films on 1.1 m substrate lengths. Superconducting YBCO films subsequently deposited on these template films have demonstrated critical current values of 200 A (1.5 cm length), 70 A (12 cm length), and 4 A (1 m length) in self fields at 75 K.

A method to deposit biaxially aligned YSZ films on polycrystalline metallic substrates at room temperature by pulsed laser deposition is discussed in a paper by W.A.J. Quinton et al. (IRC-Cambridge). The authors note that the growth direction perpendicular to the substrate plane can be adjusted between (001) and (111) direction by varying the substrate temperature from room temperature to 400^oC. In-plane alignment is achieved by inclining the substrate by 55 degrees away from the plume axis, and subsequent deposition of YBCO films on (001) in- plane aligned YSZ yielded epitaxial films with Jc values of 1.2 x 10^5A/cm^2 in zero field at 77 K.

A modified bias sputtering (MBS) technique is proposed by M. Fukutomi et al. (NRIM) for growth of biaxially textured YSZ thin films on polycrystalline metal substrates as a buffer layer for deposition of YBCO films. The authors have fabricated high-Jc YBCO films on Hastelloy tapes to obtain Jc values exceeding 10^5 A/cm^2 (77 K, 0 T). The authors suggest a variation of the bias sputtering technique to obtain textured films on larger substrates.

Other Films

The pulse characteristics of thin YBa2Cu3O7 films at high power densities is analyzed in terms of an electronic instability by P. Lahl and R. Woerdenweber (Juelich), and the critical flux flow velocity and resulting inelastic scattering rate of the quasiparticles are determined as a function of temperature and magnetic induction. Results are discussed in terms of the existing theories and literature values obtained from other experimental techniques.

Thermomagnetic properties of Nd1.85Ce0.15CuO4+-d thin films are studied as a function of oxygen content by P. Fournier et al. (Maryland). These measurements, along with the variation of the Hall coefficient and thermoelectric power with oxygen doping, suggest that a two-carrier model might be suitable to describe the transport properties of these electron-doped superconductors.

Optimized sputtered YBa2Cu3O7 thin films on CeO2-buffered sapphire substrates have been patterned into square lattices of submicrometer holes (antidots) with diameters of 250-450 nm and lattice parameters of d = 500-1000 nm by A. Castellanos (Juelich) et al. without deterioration of superconducting properties. In the mixed state, the authors observe matching effects between the Abrikosov vortex lattice and the artificial antidot lattice. Experimental results are discussed in the context of existing theories, and the existence of multi-quanta vortices confined by the holes in YBCO films are considered.

The mechanism and suppression of microcrack formation in thick epitaxial (001) YBCO films on 2" diameter CeO2-buffered sapphire substrates was studied in a paper by A. G. Zaitsev et al. (Juelich). The authors explain the microcrack formation in terms of the heteroepitaxial growth controlled by elastic strain energy, and within this framework, the critical thickness below which the films remain crack free can be increased significantly if the structural perfection of the films was sacrificed slightly. The crack-free YBCO films exhibited critical current densities exceeding 1 MA/cm^2 at 77 K, low microwave losses, and high power handling capability.

Tl-based 2212 films were prepared by A. Conde-Gallardo (CINVESTAV) et al. using a two-step procedure in which BaCaCuO precursors were first deposited from an aerosol, followed by two types of thallination and oxygenation in a single-zone reaction chamber. The authors report that prolonged thermal processing of films creates both metal-cation and oxygen-anion disorder, and that a well-defined relation between Tc and the Raman shift in O(2) vibrations exists, and may serve as an indirect indication of a lack of oxygen on the film samples.

Tapes

A sheath material consisting of a thin layer of BaZrO3 around each filament has been used in the fabrication of Bi-2223 multifilamentary tapes by Y. B. Huang and R. Fluekiger (Geneva). The authors report that transverse resistivity is enhanced by a factor of ten in the tapes, leading to a significant reduction of ac coupling losses. The tapes can also be twisted with a pitch length of 2 cm yielding an even higher decoupling effect without deterioration of transport properties. The highest critical current density measured is 15 kA/cm^2 (77 K, 0T).

A coated wire-in-tube (CWIT) method is developed by S. E. Dorris (Argonne) et al. to increase the interface area between silver and superconductor in Bi-2223 silver-sheathed superconductors. The authors report Jc values 150% higher in samples prepared by the CWIT method and stress that benefits of the method are realized only when there is good continuity of the coated wires which require a mechanical deformation sequence.

By using a continuous tube-forming-filling (CTFF) method, N. V. Vo (Los Alamos) et al. describe a manufacturing process for production of long and continuous Bi-2223 wires. Significant improvement in the interfacial uniformity is obtained through CTFF processing, and results for design and fabrication of double pancake coils from long lengths of Bi-2223/Ag CTFF multifilamentary tapes are presented.

The magnetic field dependence of the critical current I_c(B) and remanent magnetization of several multifilamentary (BiPb)2Sr2Ca2Cu3Ox tapes were measured by C. Reimann (Erlangen-Nuernberg) et al. Although self-field critical current densities J_c^0 differs widely for the tapes, the intergranular critical current densities determined from remanent magnetization were found to be equal. Results indicate that remanent magnetization is a useful tool for investigation of intergranular current carrying capacity of multifilamentary tapes without the influence of macroscopic defects. The authors emphasize that reduction of J_c^0by macroscopic defects is an important factor even though locally the filaments are of high quality.

Vortices

The intrinsic pinning in high-temperature superconductors with long- range antiferromagnetic order of rare-earth ions confined to isolated planes is described in a paper by T. Krzyszton (Polish Academy). It is shown that the behavior of several physical quantities such as magnetization, activation energy, current-voltage characteristics, and flux creep changes when the direction of the external field changes in the basal a-b plane. This work also indicates that the decay of the trapped flux is a logarithmic function of time.

Thermally activated behavior of the in-plane resistivity of Bi2Sr2CaCu2O8+d films is investigated in a paper by L. Miu (Gutenberg) et al. for magnetic fields B <= 10^4 G applied parallel to the c axis. Results suggest that in the case of a pronounced anisotropy and significant collective pinning, the vortex liquid entanglement field B_E = B_[cr] ~~ phi_0/gamma^2s^2, where s is the interlayer spacing.

In another paper, L. Miu (Gutenberg) et al. explain the resistive transition and changes in the shape of the I-V curves of Bi2Sr2CaCu2O8+d films, as a function of decreasing temperatures below T_[c0] in zero applied field, in terms of vortex-fluctuations-induced layer decoupling and vortex-antivortex unbinding showing a strong probing dependence. The determined temperature variation of the 2D I-V exponent is in agreement with recent Langevin simulations of the Coulomb gas model.

A paper by G. N. Stratopoulos (Crete) numerically shows that in the context of a dynamical Ginzburg-Landau model, under the influence of a homogeneous external current J, vortices drift against the current with velocity V = -J. In the presence of dissipation, vortices undergo skew deflection at an angle 90 degrees < delta < 180 degrees with respect to the external current. The author analytically shows and numerically verifies that the angle delta and the speed of the vortices are linked through a simple mathematical relation.

Josephson Junction

The extent to which low-frequency critical current fluctuations contribute to increased noise temperatures in HTS grain boundary junctions is examined in a paper by L. Hao (National Physical Laboratory) and J. C. Macfarlane (Strathclyde). The effective Josephson linewidth is estimated by fitting of noise-rounded dc I(V) characteristics and fitting of noise-rounded Shapiro steps. The authors discuss implications of their results for the reliability of HTS grain- boundary junctions in metrology applications such as Josephson noise thermometry.

Arrays containing more than 100 shunted bicrystal junctions are investigated in a paper by A. M. Klushin (Juelich) et al. and results show contact voltage steps with applied microwave power at temperatures above 80 K. Only current steps with index n = +-1 were observed in high-Tc circuits in contrast to three stable states seen in Nb junction arrays. The concept of a programmable voltage standard based on microwave-biased series junction arrays with two stable states is discussed.

Theory

Previous studies of numerical models for two-dimensional superconductors have investigated a thin film superconductor shaped into a spherical shell at whose center lies the end of a long thin solenoid which contains an integer flux N[phi]_0. This model is extended in a preprint by Joonhyun Yeo (Kon-kuk) and M. A. Moore (Manchester) by considering a second solenoid (carrying a flux f) inserted inside the first solenoid but passing across the sphere. The authors minimize the Ginzburg-Landau (GL) free energy at fixed N as a function of f and find that the minimum is usually achieved when the Aharonov-Bohm flux f is half a flux quantum but depending on N, the minimum may be at f=0 or values that are not rational fractions, indicating existence of non-integer flux quanta for a spherical superconductor.

A paper by Joerg Schmalian (Urbana) et al. reports an exact solution of a nearly antiferromagnetic Fermi liquid model in the limit [pi]T >> omega_[sf], which demonstrates that the broad high energy features found in ARPES measurements of the spectral density of underdoped cuprate superconductors and determined by strong antiferromagnetic (AF) correlations and precursor effects of an SDW state.

A preprint by A. J. Dolgert (Virginia) et al. studies localized stationary solutions of the one-dimensional time-dependent Ginzburg- Landau equations in the presence of a current. The authors find that these threshold perturbations separate undercritical perturbations which return to the normal phase from overcritical perturbations which lead to the superconducting phase.

Applications

Three preprints by J. R. Claycomb et al. (TCSUH) report the development a SQUID-based eddy-current corrosion and flaw-detection system utilizing HTS and mu-metal shields. Probes incorporating various combinations of excitation coil geometries and magnetic shields are tested. Authors also present modeling studies for the design and performance evaluation of the probes, and present a theoretical investigation of eddy-current induction for applications in low-frequency electromagnetic nondestructive evaluation (NDE) using the SQUIDs.

A paper by F. W. Van Keuls (NASA-Lewis) et al. reports the design, fabrication, and testing of novel YBa2Cu3O7-d/SrTiO3/LaAlO3 (YBCO/STO/LAO) and Au/SrTiO3/LaAlO3 (Au/STO/LAO) coupled microstrip line phase shifters. The impact of these phase shifters for phased array antennas are discussed.

Overviews

Fabrication of epitaxial high-Jc biaxially aligned YBCO thick films on rolling-assisted-biaxially textured substrates is summarized in a paper by A. Goyal (Oak Ridge) et al. Films grown using laser ablation on RABiTS substrates have critical current densities exceeding 10^6 A/cm^2 at 77 K in zero field and have field dependencies similar to epitaxial films on single-crystal ceramic substrates. The authors believe that conductors fabricated by this method offer a promising route towards the fabrication of long lengths of high-Jc wire capable of carrying high currents at elevated temperatures and magnetic fields. (50 refs.)

A summary of properties of electron-doped superconductors Re2-xCexCuO4 (Re=Nd,Pr,Sm) is presented in a review by P. Fournier et al. (Maryland). The authors address the peculiar disparities in many properties of these materials in comparison to hole-doped cuprates, and discuss their superconducting properties including s-wave-like temperature dependence of the penetration depth and lack of evidence of an anisotropic (d-wave) gap function in these materials. (56 refs.).

The use of neutron spectroscopy as a tool for determination of crystal field (CF) potential in rare-earth based high-Tc superconductors is reviewed in a paper by J. Mesot and A. Furrer (ETH Zurich and PSI). The authors discuss temperature dependent relaxation rate of CF excitations in both optimally and underdoped regimes and present evidence for the opening on an electronic gap in the normal state of underdoped superconductors. (77 refs.).

Thesis

Low energy electrodynamics of high-Tc superconductors are studied in the Ph.D. thesis of J. Feenstra (Groningen). The author reports results of FIR spectroscopy and mm-wave transmission on conventional and high-Tc superconductors, and non-equilibrium superconductivity studies by photoinduced activation of mm-wave absorption (PIAMA). (50 refs.).

Contributed by Sreeparna Mitra

Contents: Technology News begins on page 5; Cryo Applications begins on page 6; Preprints begin on page 7; and Coming Events begin on page 12.

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.

TECHNOLOGY NEWS (Also see Applications section of Nota Bene.)

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.

New Consortium: The SHIFT (Superconducting High Tc Coils for High Field Technologies) Project, established in May of this year, brings together six partners from five European countries to create a consortium. The participants are: (1) Electricite de France, the French electrical power utility company; (2) Alcatel Cable, subsidiary of the Alcatel- Alsthom group, the French manufacturer of telecommunication, transport, and electrical equipment; (3) Oxford Instruments, the British magnet manufacturer; (4) Hoechst, the German chemical company; (5) National High Field Magnet Lab from Nijmegen University in the Netherlands that specializes in high-field measurements and technologies; and (6) Technical University of Tampere from Finland with expertise in magnetometry.

The objective of the consortium is to develop basic tech-nologies for fabrication of high-temperature superconducting (HTS) coils at high fields operating in the temperature range 20 - 40 K. The realization of 6 Tesla demonstration magnets cooled by closed-cycle refrigeration is the main project goal, which will represent a significant step toward first prototypes that can reach the market in the next five-year period. The aim is to reach this goal by considering the following conductor technologies: (1) Melt-cast-processed bulk material using the 92 K Bi- phase -- the process offers a sufficient material performance for reasonable costs; (2) Dip-coated conductor fabrication also using the 92 K Bi-phase -- the process is of intermediate cost and is expected to have good dc performance; and (3) Twisted multifilamentary powder-in- tube technology using the 100 K or the 92 K Bi-phase -- the process is more expensive but expected to have good performance under dc and under varying conditions.

The identified target products are dc magnets for medical imaging (MRI), instrumentation, and laboratory use, and pulsed magnets for superconducting magnetic energy storage (SMES) systems in the 1--20 MJ range devoted to power quality.

For further information, contact Clotilde Levillain, telephone +33 1 47 65 31 91, telefax +33 1 47 65 32 51, e-mail clotilde.levillain@der.edfgdf.fr.

Under a recent contract between Pirelli Cables and Systems and Electricite de France (EDF), the companies will jointly study, manufacture, and extensively test a 30-50 meter prototype system for an underground high-voltage power cable at EDF's Paris-based power facility. The cable will be built using HTS wire manufactured by American Superconductor Corporation (AMSC), the technology for which was developed at AMSC under a joint Pirelli/AMSC development program. The cable features a design specifically developed by Pirelli Cable Systems for EDF to meet the stringent European electric network requirements. For further information, contact Heather Robb or Kim Miller, FitzGerald Communications, Inc., telephone (617) 494-9500; or American Superconductor Corporation, Two Technology Drive, Westborough, MA 01581; telephone (508) 836-4200; telefax (508) 836-4714.

Contributed by Sreeparna Mitra

CRYO APPLICATIONS

ClearSite(TM}: A Cryoelectronic Subsystem by John Ramsden and Randy Simon, Conductus, Inc.

The first sizable mainstream deployment of high-temperature superconductive electronics technology will possibly be in the form of receiver front-end subsystems for wireless communications. At least four companies are presently delivering products of this type to equipment manufacturers and service providers in the wireless industry. In some cases, HTS-based systems have been in the operational network for more than a year.

At Conductus, wireless subsystems are being marketed under the ClearSite(TM} name and are representative of the cryoelectronic system products that characterize this application of superconductivity. The features and benefits associated with superconductive wireless filter technology have been discussed in a number of previous articles in trade magazines and in the technical literature. In this article, we discuss some of the design and performance considerations of the cryogenics for the ClearSite(TM} product, and, by inference, for cryogenic receiver subsystems in general.

ClearSite(TM} is a general platform designed to support a variety of filter configurations including omni with diversity (2-channel), 3- sector (6-channel), and 6-sector (12-channel). In this context, channels comprise HTS filter and cryocooled low-noise amplifier pairs. To support all these potential configurations, a cryocooler with 6 W of cooling power at 60 K was selected.

Apart from the cooling power, equally important considerations with respect to the cooler in system design included having a small profile, being rack mountable, and having a proven long maintenance-free lifetime. The cooler selected for the application is a Gifford-McMahon unit manufactured by CTI-Cryogenics.

Extended cooler lifetime in this application is valuable only when combined with extended vacuum life in the cryostat which contains the filters and LNAs. The combination determines the true period of performance for the system. Extended vacuum life is achieved through a combination of proper design, special fabrication processes, special cleaning processes, and proper gettering implementation. From a design perspective, UHV practices must be followed, including attention to such issues as virtual leaks and hermiticity, as well as careful selection of materials to assure minimal outgassing.

As in any cryoelectronic system, thermal management is a prime consideration with the design constraint being the maximum cooling power of the cryocooler at the end of its design life. The primary issue in thermal management is the control of the heat load into the system. As usual, there are tradeoffs to be made -- in this case the rf performance of cables versus their thermal loading. More generally, thermal management procedures include special treatment of exposed surfaces to minimize and control emissivity (which determines the radiation heat load) and the minimizing of thermal gradients across the HTS filters by proper selection of architecture and materials. Other thermal issues include the necessity to match thermal expansion properties of the filters with the package materials over the entire temperature range so as not to stress the filters during thermal excursions of the system.

Generally, implicit in the design of cryogenic system is an inherent level of fragility required to achieve sufficiently low thermal loads. In spite of this requirement, commercial units must be able to withstand transportation by common carrier and a variety of handling conditions. Therefore, at a system level they must be quite robust. Routine testing against vibration, thermal shock, and a variety of other environmental conditions is a necessity.

Another important consideration for these early mainstream insertions of cryoelectronic technology is providing reliable performance to customers and giving them timely recourse when problems do arise. Even though the system design is very robust and failures are highly unlikely, new technology always represents a cause for concern. For this reason, in ClearSite(TM}, major components or failure modes are alarmed to give early identification of problems to allow the problems to be remedied without loss of service.

To summarize, superconductive filter technology in conjunction with cryocooler semiconductor amplifiers have been shown to provide performance benefits in wireless base station applications. In order to bring these benefits into the commercial marketplace, a rapidly maturing cryopackaging technology has been developed that permits the manufacture of robust and reliable electronic products.

PREPRINTS To obtain a particular preprint, contact the first author at the address given at the end of the citation. Help us expand this list by sending us your complete preprint. Please specify where and when your paper was submitted. An * next to an entry indicates it is a correction or revision of a previous entry. PACS codes and/or key words are given at the end of the citation.

P. N. Arendt, S. R. Foltyn, J. R. Groves, R. F. DePaula, P. C. Dowden, J. M. Roper, and J. Y. Coulter, "YBCO/YSZ Coated Conductors on Flexible Ni Alloy Substrates." To be published in Appl. Supercond. Center for Materials Science, Mail Stop K675, Los Alamos National Laboratory, Los Alamos, NM 87545; telephone (505) 667-9243; telefax (505) 665-2992.

Liliana Arrachea and A. A. Aligia, "Superconductivity in a Generalized Hubbard Model." To be published in Physica C (in press). Contact A. A. Aligia, Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica, 8400 Bariloche, ARGENTINA; telephone +54 944 45170; telefax +54 944 45299; e-mail aligia@cab.cnea.edu.ar. Key words: generalized Hubbard model, three-body interactions, superconductivity, phase diagram, Hartree-Fock-BCS approximation.

V. Badri, Y. T. Wang, and A. M. Hermann, "Significantly Enhanced Flux Pinning in the Bi-Substituted TIBa2Ca2Cu3Oy System." To be published in Appl. Phys. Lett. Contact A. M. Hermann, Superconductivity Laboratories, Department of Physics, University of Colorado, Campus Box 390, Boulder, CO 80309-0390; telephone (303) 492-2661; telefax (303) 492-2998; e-mail allen.hermann@colorado.edu.

Michael Becht, "Metal-Organic Chemical Vapor Deposition as an Emerging Technique for the Fabrication of YBa2Cu3Ox Tapes." To be published in Appl. Supercond. Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 1-10-13 Shinonome, Koto-ku, Tokyo 135, JAPAN; telephone +81 3 3536 5709; telefax +81 3 3536 5717; e- mail becht@gol.com.

W. Bieger, G. Krabbes, P. Schaetzle, A. Leistikow, J. Thomas, and P. Verges, "Modified Processing, Microstructure and Improved Properties of NdBaCuO Bulk Materials." To be published in Mater. Sci. Eng. Institut fuer Festkoerper- und Werkstofforschung Dresden, Postfach 27 00 16, D- 01171 Dresden, GERMANY; G. Krabbes' telephone +49 351 2582 395; telefax +49 351 2582 314.

E. Bruneel, F. Persyn, and S. Hoste, "Mechanical and Superconducting Properties of BiPbSrCaCuO/PE and BiPbSrCaCuO/MgO Composites." To be published in Supercond. Sci. & Technol.: Proc. of Supercond. Mater. Aspects--Res. & Technol. (SMART 97), Liege, Belgium, June 26-29, 1997. Department of Inorganic and Physical Chemistry, Division of Superconducting Materials, University of Ghent, Krijgslaan 281, B-9000 Ghent, BELGIUM; e-mail els.bruneel@rug.ac.be.

M. Casas, S. Fujita, M. de Llano, A. Puente, A. Rigo, and M. A. Solis, "The Cooper Pair Dispersion Relation." To be published in Physica C. Contact M. A. Solis, Instituto de Fisica, UNAM, 0100 Mexico DF, MEXICO; e-mail solis@sysul1.ifisicacu.unam.mx. Key words: phonon mechanism, electron-phonon coupling, pair breaking. 03.65.Ge; 71.10.Li; 05.30.Fk.

A. Castellanos, R. Woerdenweber, G. Ockenfuss, A.v.d. Hart, and K. Keck, "Preparation of Regular Arrays of Antidots in YBa2Cu3O7 Thin Films and Observation of Vortex Lattice Matching Effects." To be published in Appl. Phys. Lett. Institut fuer Schicht- und Ionentechnik, Forschungszentrum Juelich, D-52425 Juelich, GERMANY. 74.60.Ge.

A. H. Castro Neto and F. Guinea, "Superconductivity, Josephson Coupling and Order Parameter Symmetry in Striped Cuprates." Department of Physics, University of California, Riverside, CA 92521; e-mail neto@phyun6.ucr.edu; preprint also available at cond-mat@xxx.lanl.gov (#9709324). 74.20.Mn; 74.50.+r; 74.72.Dn; 74.80.Bj.

Victor V. Chabanenko, Alexander I. D'yachenko, Henryk Szymczak, and Stanislaw Piechota, "Failure of Textured YBaCuO Samples in the Strong Magnetic Field." To be published in Physica C (in press). Physical and Technical Institute, National Academy of Sciences, Str. R. Luxemburg 72, 340114 Donetsk, UKRAINE; telefax +380 622 52 1074; e-mail chaban@host.dipt.donetsk.ua. Key words: flux pinning, magnetization, lamination, twin boundaries, YBaCuO.

C. L. Chen, Y. Cao, Z. H. Zhang, Z. J. Huang, A. Brazdeikis, Q. D. Jiang, I. A. Rusakova, Y. Y. Sun, W. K. Chu, and C. W. Chu, "Epitaxial Growth of a-Axis Oriented SrRuO3 Thin Films on (110) SrTiO3." Preprint #97:119; submitted to Appl. Phys. Lett. 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.

B. Chesca, "Theory of rf SQUIDs Operating in the Presence of Large Thermal Fluctuations." To be published in J. Low Temp. Phys. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich, D-52425 Juelich, GERMANY; telefax +49 2461 612940; e-mail chesca@jupiter.isi.kfa-juelich.de. Key words: SQUIDs, thermal fluctuations. 85.25.Dq.

J. R. Claycomb, N. Tralshawala, H. M. Cho, M. Boyd, and J. H. Miller, Jr., "Superconducting Quantum Interference Devices for Nondestructive Testing." Preprint #97:116; to be published in the Proc. of the Workshop on Intelligent NDE Sciences for Aging and Futuristic Aircraft, El Paso, Tex., Sept. 30-Oct. 2, 1997. 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. Key words: SQUID, high-temperature superconductor, magnetic imaging, eddy-current imaging, nondestructive testing, corrosion.

J. R. Claycomb, N. Tralshawala, and J. H. Miller, Jr., "A Theoretical Investigation of Eddy Current Induction for Low Frequency SQUID Based Nondestructive Evaluation." Preprint #97:117; submitted to IEEE Trans. Magn. 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. R. Claycomb, N. Tralshawala, and J. H. Miller, Jr., "Time Harmonic Simulations for the Design of a Low-Frequency Eddy Current Probe for Nondestructive Testing." Preprint #97:118; submitted to Rev. Sci. Instrum. 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. 02.70.Dh; 07.55.Nk; 81.70.Ex; 85.25.Dq.

A. Conde-Gallardo, G. Contreras-Puente, M. Jergel, C. Falcony, A. Escamilla, and F. Hanic, "Influence of Processing Conditions of TI-2212 Superconducting Films Deposited from an Aerosol upon Their Tc and Oxygen Raman Modes." To be published in Physica C (in press). Contact G. Contreras-Puente, Escuela Superior de Fisica y Matematicas, IPN-UPALM, Apdo. Postal 75-373, Mexico, D.F., MEXICO; telefax +52 5 586-2825; e- mail gerardo@esfm.ipn.mx. Key words: TI-2212 films, aerosol deposition, Raman scattering, oxygen non-stoichiometry, defect structure.

A. E. Curzon, F. Hamed, and S. Gygax, "Current and Potential Distributions in Highly Anisotropic Superconductors with Inclusions." To be published in Physica C. Department of Physics, Simon Fraser University, 8888 University Drive, Burnaby, B.C., CANADA V5A, 1S6; telephone (604) 291-4181; telefax (604) 291-3592; e-mail curzon@sfu.ca. Key words: electrical resistivity, whiskers, intercalated layers.

M. Darula, H. Kohlstedt, L. Amatuni, and A. M. Klushin, "Stack Josephson Junctions with Sidewall Shunt." To be published in the Proc. of the 3rd European Conf. on Appl. Supercond. (EUCAS'97), Veldhoven, The Netherlands, June 30-July 3, 1997. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY; e-mail m.darula@fz-juelich.de.

P. Diko and K. C. Goretta, "Macroscopic Shape Change of Melt-Processed YBa2Cu3Ox-Y2BaCuO5 Bulk Superconductors." Submitted to Physica C. Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04353 Kosice, SLOVAKIA; preprint also available from Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.

Andrew J. Dolgert, Thomas Blum, Alan T. Dorsey, and Michael Fowler, "Nucleation and Growth of the Superconducting Phase in the Presence of a Current." Department of Physics, University of Virginia, McCormick Road, Charlottesville, VA 22901; e-mail ajd2m@virginia.edu; preprint also available at cond-mat@xxx.lanl.gov (#9709125). 74.40.+k; 74.60.Jg; 74.76.-w; 64.60.Qb.

S. E. Dorris, N. Ashcom, T. Truchan, N. Vasanthamohan, D. A. Burlone, and L. D. Woolf, "Coated-Wire-in-Tube Processing of Bismuth-2223 Superconductors." Presented at the 1997 Annual Meeting of the Amer. Ceram. Soc., Cincinnati, Ohio, May 4-7, 1997. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.

Bokke Johannes Feenstra, "Low Energy Electrodynamics of High Tc Superconductors." Submitted as a Ph.D. thesis (University of Groningen). Department of Physics, Center for Superconductivity Research, University of Maryland, College Park, MD 20742-4111; telephone (301) 405-6132; telefax (301) 314-9541; e-mail feenstra@squid.umd.edu.

B. J. Feenstra, J. Schuetzmann, D. van der Marel, R. Perez Pinaya, and M. Decroux, "Non-Equilibrium Superconductivity and Quasiparticle Dynamics Studied by Photoinduced Activation of mm-Wave Absorption (PIAMA)." Submitted to Phys. Rev. Lett. Department of Physics, Center for Superconductivity Research, University of Maryland, College Park, MD 20742-4111; telephone (301) 405-6132; telefax (301) 314-9541; e-mail feenstra@squid.umd.edu; preprint also available at cond-mat@xxx.lanl.gov (#9709005). 74.10.+v; 74.76.-w; 74.40.+k; 63.20.Ls.

Yong Feng, Lian Zhou, J. G. Wen, and N. Koshizuka, "Flux Pinning and Flux Creep in Sn-Doped Powder Melting Processed YBCO." To be published in Physica C (in press). Northwest Institute for Nonferrous Metal Research, P.O. Box 51, Xi'an Shaanxi 710016, PEOPLE'S REPUBLIC OF CHINA; telephone +86 29 622 4487; telefax +86 29 623 1103; e-mail pxzhang@xanet.edu.cn.

P. Fournier, X. Jiang, W. Jiang, S. N. Mao, T. Venkatesan, C. J. Lobb, and R. L. Greene, "Thermomagnetic Transport Properties of Nd1.85Ce0.15CuO4+d Films: Evidence for Two Types of Charge Carriers." To be published in Phys. Rev. B (in press). Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, MD 20742-4111; e-mail pfournie@squid.umd.edu. 72.15.Jf; 74.25.Fy; 74.25.Jb; 74.62.Bf.

P. Fournier, E. Maiser, and R. L. Greene, "Current Research Issues for the Electron-Doped Cuprates." Submitted to the Proc. of the NATO Adv. Study Inst. on the Gap Symmetry and Fluctuations in High-Tc Supercond., Inst. d'Etudes Scientifiques de Cargese, Corsica, France, Sept. 1-12, 1997. Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, MD 20742-4111; e-mail pfournie@squid.umd.edu.

H. C. Freyhardt, J. Hoffmann, J. Wiesmann, J. Dzick, K. Heinemann, A. Isaev, A. Usoskin, and F. Garcia-Moreno, "Y-123 Films on Technical Substrates." To be published in Appl. Supercond. Institut fuer Metallphysik, Universitaet Goettingen, Windausweg 2, D-37073 Goettingen, GERMANY; telephone +49 551 394492; telefax +49 551 77 3650.

M. Fukutomi, M. Saitoh, K. Komori, and K. Togano, "Preparation of In- Plane Textured Buffer Layers for YBa2Cu3Oy Film Growth by Modified Bias Sputtering." To be published in Appl. Supercond. National Research Institute for Metals, 1-2-1 Sengen, Tsukuba-shi, Ibaraki 305, JAPAN.

A. M. Ghorayeb, O. Monnereau, L. Fermond, T. Badeche, N. E. Hussey, C. D. Dewhurst, I. R. Fisher, W. S. Seow, and R. A. Doyle, "Electrical Resistivity of Iodine-Intercalated Bi2Sr2CaCu2O8 Subjected to a Magnetic Field." To be published in Molecular Crystals and Liquid Crystals: Proc. of the 9th Int. Symp. on Intercalation Compounds (ISIC 9), Bordeaux-Arcachon, France, May 25-29, 1997. Laboratoire Materiaux Organisation et Proprietes (MATOP), associe au CNRS, Case 151, Faculte des Sciences et Techniques et St. Jerome, Universite d'Aix-Marseille III, F-13397 Marseille Cedex 20, FRANCE; telephone +33 91 28 8782; telefax +33 91 28 8775; e-mail ghorayeb@matop.u-3mrs.fr. Key words: intercalation, superconductivity, electrical resistivity, magnetic field.

S. N. Gordeev, D. Bracanovic, A. P. Rassau, P.A.J. de Groot, R. Gagnon, and L. Taillefer, "Current-Induced Resistivity Switching Effects Near the Melting Line in Detwinned YBa2Cu3O7-d ." To be published in Phys. Rev. B. Department of Physics, University of Southampton, Southampton, SO17 1BJ, UNITED KINGDOM; A. P. Rassau's telephone +44 1703-592058 or -595000; telefax +44 1703-593910; e-mail apr@phys.soton.ac.uk. 74.25.Fy; 74.60.Ge; 74.72.Bk.

A. Goyal, D. P. Norton, D. K. Christen, E. D. Specht, M. Paranthaman, D. M. Kroeger, J. D. Budai, Q. He, F. A. List, R. Feenstra, H. R. Kerchner, D. F. Lee, E. Hatfield, P. M. Martin, J. Mathis, and C. Park, "Epitaxial Superconductors on Rolling-Assisted-Biaxially-Textured-Substrates (RABiTS): A Route Towards High Critical Current Density Wire." To be published in Appl. Supercond. Materials Science Section, Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831; telephone (423) 574-1587; telefax (423) 574-7659.

B. Grevin, Y. Berthier, I. Monot, J. Wang, and F. Weiss, "Chemical Phase Separation in Carbon Doped YBa2Cu3O6+x: A [63,65]^Cu NQR Study." To be published in Physica C (in press). Laboratoire de Spectrometrie Physique, Universite Joseph Fourier Grenoble 1, BP 87, F-38402 Saint- Martin d'Heres Cedex, FRANCE; telephone +33 4 7651 4288; telefax +33 4 7651 4544; e-mail benjamin.grevin@ujf-grenoble.fr. Key words: YBCO, NQR, spin-lattice relaxation time T_1, carbonates CO3. 74.72.Bk; 76.60.Gv; 74.80.Bj.

Qiang Han and Liyuan Zhang, "Ginzburg-Landau Theory and Vortex Structure for a d+s Wave Superconductor with Orthorhombic Distortion." To be published in Phys. Rev. B. Contact Liyuan Zhang, Department of Physics, Peking University, Beijing 100871, PEOPLE'S REPUBLIC OF CHINA; telefax +86 10 6275 1615. Key words: superconductor, G-L theory. 74.20.De; 74.60.-w; 74.60.Ec; 74.72.-h.

L. Hao and J. C. Macfarlane, "Estimation of the Noise Temperature of Y- Ba-Cu-O Grain Boundary Josephson Junctions." To be published in Physica C. Centre for Quantum Metrology, National Physical Laboratory, Teddington TW11 0LW, UNITED KINGDOM; e-mail linghao@npl.co.uk. Key words: fluctuation effects, Josephson junction, grain boundary, Shapiro step.

K. Hasegawa, K. Fujino, H. Mukai, M. Konishi, K. Hayashi, K. Sato, S. Honjo, Y. Sato, H. Ishii, and Y. Iwata, "Biaxially Aligned YBCO Film Tapes Fabricated by All Pulsed Laser Deposition." To be published in Appl. Supercond. Osaka Research Laboratories, Sumitomo Electric Industries, Ltd., 1-1-3 Shimaya, Konohana-ku, Osaka 554, JAPAN.

Y. B. Huang and R. Fluekiger, "Reducing ac Losses of Bi(2223) Multifilamentary Tapes by Oxide Barriers." To be published in Physica C. Applied Physics Group, University of Geneva, 20 rue Ecole de Medicine, CH-1211 Geneva 4, SWITZERLAND; telephone +41 22 702 6593; telefax +41 22 781 0980; e-mail huang@sc2a.unige.ch. Key words: oxide barrier, ac losses, Bi(2223) tape, fabrication. 74.72.Hs; 85.25.Kx.

A. Ignatiev, P. C. Chou, Q. Zhong, X. Zhang, and Y. M. Chen, "Photo- Assisted MOCVD Growth of YBCO Thick Films for Wire Applications." To be published in Appl. Supercond. Texas Center for Superconductivity and Space Vacuum Epitaxy Center #724, S&R1, University of Houston, 4800 Calhoun Road, Houston, TX 77204-5507; telephone (713) 743-3621; telefax (713) 747-7724.

Y. Iijima, M. Hosaka, N. Tanabe, N. Sadakata, T. Saitoh, O. Kohno, and K. Takeda, "Processing and Transport Characteristics of YBCO Tape Conductors Formed by IBAD Method." To be published in Appl. Supercond. Materials Research Laboratory, Fujikura Ltd., 1-5-1 Kiba, Koto-ku, Tokyo 135, JAPAN; telefax +81 3 5606 1512; e-mail ijm@rd.fujikura.co.jp. Key words: ion-beam-assisted deposition, superconducting tape conductors, YBa2Cu3O7-x, biaxially aligned structure, intergranular weak links.

M. Kanai, D. Matsuura, T. Kawai, and H. Miki, "Electronic States in La2- xSrxNiO4 (x = 0 to 1.20) Investigated by Scanning Tunneling Spectroscopy." To be published in Physica C (in press). Contact T. Kawai, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567, JAPAN; telephone +81 6879 8447; telefax +81 6875 2440. Key words: electronic structure, metal- insulator transition, scanning tunneling spectroscopy.

A. M. Klushin, S. I. Borovitskii, C. Weber, E. Sodtke, R. Semerad, W. Prusseit, V. D. Gelikonova, and H. Kohlstedt, "Programmable Voltage Standards Based on HTS Josephson Junction Arrays." To be published in the Proc. of the 3rd European Conf. on Appl. Supercond. (EUCAS'97), Veldhoven, The Netherlands, June 30-July 3, 1997. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY; e-mail klushin@isitel1.isi.kfa-juelich.de.

K. A. Kouznetsov, A. G. Sun, B. Chen, A. S. Katz, S. R. Bahcall, John Clarke, R. C. Dynes, D. A. Gajewski, S. H. Han, M. B. Maple, J. Giapintzakis, J.-T. Kim, and D. M. Ginsberg, "c-Axis Josephson Tunneling Between YBa2Cu3O7-d and Pb: Direct Evidence for Mixed Order Parameter Symmetry in a High-Tc Superconductor." To be published in Phys. Rev. Lett. Department of Physics, University of California, Berkeley, CA 94720; John Clarke's telephone (510) 642-3069; telefax (510) 642-1304. 74.50.+r; 74.72.Bk.

G. Krabbes, W. Bieger, P. Schaetzle, and U. Wiesner, "Improved HTSC Bulk Materials: A Thermodynamic Approach to Processing." To be published in Supercond. Sci. Tech. Institut fuer Festkoerper- und Werkstofforschung Dresden, Postfach 27 00 16, D-01171 Dresden, GERMANY; telephone +49 351 2582 395; telefax +49 351 2582 314.

Tomasz Krzyszton, "Intrinsic Pinning in Antiferromagnetic Layered Superconductor." To be published in Physica C. Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 937, PL-50 950 Wroclaw 2, POLAND; telephone +48 71 35021; telefax +48 71 441029; e-mail krzyszto@apollo.int.pan.wroc.pl.

S. G. Lachenmann, I Friedrich, A. Foerster, D. Uhlisch, and A. A. Golubov, "Charge Transport in Superconductor/Semiconductor/Normal Conductor Step Junctions." To be published in Phys. Rev. B. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich, D-52425 Juelich, GERMANY. 74.50.+r; 73.25.+i; 73.40.Sx.

P. Lahl and R. Woerdenweber, "dc-Pulse Characteristic of Thin YBa2Cu3O7 Films." To be published in the Proc. of the 3rd European Conf. on Appl. Supercond. (EUCAS'97), Veldhoven, The Netherlands, June 30-July 3, 1997. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich, D- 52425 Juelich, GERMANY.

W. H. Lee and B. C. Huang, "Changes in Doping State of TI(Sr2- xRx)CaCu2O7-d (R=Sm,Eu,Dy) System." To be published in Physica C (in press). Department of Physics, National Chung Cheng University, Ming- Hsiung, Chia-Yi 621, Taiwan, REPUBLIC OF CHINA; telephone +886 5 2720 586; telefax +886 5 2720 587; e-mail whlee@phy.ccu.edu.tw.

C. Looney, J. S. Schilling, S. Doyle, and A. M. Hermann, "Possibility for Oxygen Relaxation Below 15 K in Superconducting TI2Ba2CuO6+x." To be published in Physica C (in press). Department of Physics, Washington University, C.B. 1105, One Brookings Drive, St. Louis, MO 63130; telephone (314) 935-6239.

J. Mesot and A. Furrer, "The Crystal Field in Rare Earth Based High- Temperature Superconductors." To be published in J. Supercond. Laboratory for Neutron Scattering, ETH Zurich & Paul Scherrer Institute, CH-5232 Villigen PSI, SWITZERLAND; telephone +41 56 310 2088; telefax +41 56 310 2939; e-mail albert.furrer@psi.ch. Key words: superconductivity, crystal field, rare earth, relaxation, gap symmetry.

D. Mihailovic, B. Podobnik, J. Demsar, G. Wagner, and J. Evetts, "Divergence of the Quasiparticle Lifetime with Doping and Evidence for Pre-Formed Pairs Below T* in YBa2Cu3O7-d: Direct Measurements by Femtosecond Time-Resolved Spectroscopy." Presented at the 1997 Conf. on Spectroscopies in Novel Supercond. (SNS'97), Falmouth, Mass., Sept. 14- 18, 1997; to be published in J. Phys. Chem. Solids. Jozef Stefan Institute, P.O. Box 3000, Jamova 39, 1001 Ljubljana, SLOVENIA.

R. G. Mints and I. B. Snapiro, "Proximity Effect Enhancement Induced by Roughness of SN Interface." Submitted to Phys. Rev. B. Max-Planck- Institut fuer Metallforschung, D-70569 Stuttgart, GERMANY; telephone +49 711 689-1919; telefax +49 711 689-1932 or -1912; e-mail at Tel Aviv, Israel mints@ccsg.tau.ac.il; preprint also available at cond- mat@xxx.lanl.gov (#9709314). 74.60.Ge.

L. Miu, G. Jakob, P. Haibach, F. Hillmer, C. C. Almasan, and H. Adrian, "Vortex Liquid Entanglement in Bi2Sr2CaCu2O8+d Films in the Presence of Quenched Disorder." Department of Physics, Kent State University, Kent, OH 44242. 74.72.Hs; 74.76.Bz; 74.60.Ge; 74.25.Fy.

L. Miu, G. Jakob, P. Haibach, Th. Kluge, U. Frey, P. Voss-de Haan, and H. Adrian, "Length-Scale-Dependent Vortex-Antivortex Unbinding in Epitaxial Bi2Sr2CaCu2O8+d Films." Department of Physics, Kent State University, Kent, OH 44242. 74.60.Jg; 74.60.Ge; 74.40.+k.

V. V. Moshchalkov, M. Baert, V. V. Metlushko, E. Rosseel, M. J. Van Bael, K. Temst, Y. Bruynseraede, and R. Jonckheere, "Pinning by an Antidot Lattice: The Problem of the Optimum Antidot Size." Submitted to Phys. Rev. B. Laboratorium voor Vaste-Stoffysika en Magnetisme, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, BELGIUM; telephone +32 16 32 76 18; telefax +32 16 32 79 83; e-mail victor.moshchalkov@fys.kuleuven.ac.be. 74.60.Ge; 74.76.Db; 74.25.Ha.

J. J. Palacios, "Customizing Vortex Lattices in Strong Type-II Superconducting Nanostructures." Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055; telephone (606) 257- 4938; telefax (606) 323-2846; e-mail palacios@pa.uky.edu; Web site http://www.pa.uky.edu/~palacios; preprint also available at cond- mat@xxx.lanl.gov (#9710042). 74.60.Ec; 74.76.-w.

S. J. Phillipson, M. A. Moore, and T. Blum, "A Study of Nonlocal Conductivity in High-Temperature Superconductors." Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UNITED KINGDOM; e-mail sarah@a13.ph.man.ac.uk; preprint also available at cond-mat@xxx.lanl.gov (#9710078). 74.60.-w; 74.25.Fy; 74.60.Ge; 74.20.De.

R. Pinto, L. C. Gupta, Rajni Sharma, A. Sequiera, and K. I. Gnanasekar, "Superconductivity in Lu1-xCaxBa2Cu3O6+d: Holes Generated by Ca." To be published in Physica C (in press). Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, INDIA; telephone +91 22 215- 2971 or -2979; telefax +91 22 215-2110 or -2181. Key words: superconductivity, tetragonal Lu1-xCaxBa2Cu3O6+d, neutron diffraction, overdoping.

D. Qu, Donglu Shi, Shih-Lin Lu, Altan M. Ferendeci, and David Mast, "Seeded Melt Growth of YBa2Cu3Ox for Novel Millimeter Wave Resonators." Submitted to Appl. Phys. Lett. Department of Materials Science and Engineering, University of Cincinnati, Cincinnati, OH 45221; telephone (513) 556-3096; telefax (513) 556-2569.

W.A.J. Quinton and F. Baudenbacher, "Deposition of Biaxially Aligned YSZ Films on Inclined Polycrystalline Metallic Substrates for YBa2Cu3O7-d Tapes." To be published in Physica C. IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UNITED KINGDOM; telephone +44 1223 337-047 or -076; telefax +44 1223 337-074; e-mail wajq2@cus.cam.ac.uk. Key words: YBaCuO, YSZ, pulsed-laser deposition, thin films, Hastelloy.

C. Reimann, O. Waldmann, P. Mueller, M. Leghissa, and B. Roas, "Current Carrying Capability of Multifilamentary (BiPb)2Sr2Ca2Cu3Ox Tapes Determined from Transport and Magnetization Measurements." To be published in Appl. Phys. Lett. Physikalisches Institut III, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Str. 1, D-91058 Erlangen, GERMANY; telephone +49 9131 85 7082; telefax +49 9131 15249; e-mail reimann@physik.uni-erlangen.de.

P. Schaetzle, A. Berning, W. Bieger, and G. Krabbes, "Preparation and Melt Processing of (RE,Y)BaCuO (RE=Nd,Sm) and (Nd,Sm)BaCuO Composites." To be published in Mater. Sci. Eng. B. Institute of Solid State and Materials Research Dresden, P.O. Box 270016, D-01171 Dresden, GERMANY; G. Krabbes' telephone +49 351 2582 395; telefax +49 351 2582 314. Key words: (Re,Y)BaCuO (RE=Nd,Sm), (Nd,Sm)BaCuO composites, solid solution, stoichiometry stabilization, critical currents.

Joerg Schmalian, David Pines, and Branko Stojkovic, "Weak Pseudogap Behavior in the Underdoped Cuprate Superconductors." Loomis Laboratory of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL 61801. 74.25.-q; 74.25.Ha.

G. N. Stratopoulos, "Vortex Pull by an External Current." Preprint #Crete-97-19. Department of Physics and Institute of Plasma Physics, University of Crete and Research Center of Crete, P.O. Box 2208, 710 03 Heraklion, Crete, GREECE; e-mail stratos@physics.uch.gr; preprint also available at cond-mat@xxx.lanl.gov (#9708235).

M. Ullrich, A. Leenders, J. Krelaus, L.-O. Kautschor, H. C. Freyhardt, L. Schmidt, F. Sandiumenge, and X. Obradors, "High Temperature Deformation of Bridgman Melt-Textured YBCO." Presented at the Int. Workshop on the Proc. and Appl. of Supercond. (RE)BCO Large Grain Materials, Cambridge, U.K., July 7-9, 1997; to be published in J. Mat. Sci. Eng. B. Zentrum fuer Funktionswerkstoffe gGmbH Goettingen, Windausweg 2, D-37073 Goettingen, GERMANY; telephone +49 551 50717 30; telefax +49 551 50717 50; e-mail ullrich@umpsun1.gwdg.de. Key words: mechanical properties, YBCO. 74.25.Ld; 62.20.Fe; 74.72.Bk.

F. W. Van Keuls, R. R. Romanofsky, D. Y. Bohman, M. D. Winters, F. A. Miranda, C. H. Mueller, R. E. Treece, T. V. Rivkin, and D. Galt, "(YBa2Cu3O7-d,Au)/SrTiO3/LaAlO3, Thin Film Conductor/Ferroelectric Coupled Microstripline Phase Shifters and Their Potential for Phased Array Applications." To be published in Appl. Phys. Lett. National Aeronautics and Space Administration, Lewis Research Center, 21000 Brookpark Road, Cleveland, OH 44135-3191; telephone (216) 433-3379 or -4000; telefax (216) 433-8705; e-mail vankeuls@lerc.nasa.gov.

A. L. Vasiliev, D. S. Linehan, E. P. Kvam, L. Hou, and M. W. McElfresh, "Single Variant Orientational Growth of YBa2Cu3O7-x on Vicinal (011) SrTiO3 Substrates Observed by Electron Microscopy." To be published in Physica C (in press). Contact E. P. Kvam, School of Materials Engineering, Purdue University, W. Lafayette, IN 47907; telephone (317) 494-4097; telefax (317) 494-1204; e-mail kvam@purdue.edu. Key words: YBCO, films, vicinal surface, microstructure, TEM. 74.76.Bz; 61.72.Ff; 68.55.Jk.

Y.-M. Vilk, S. Allen, H. Touchette, S. Moukouri, L. Chen, and A.-M.S. Tremblay, "Attractive Hubbard Model and Single-Particle Pseudogap Due to Classical Pairing Fluctuations in Two Dimensions." Contact A.-M.S. Tremblay, Centre de Recherche en Physique du Solide and Department de Physique, Universite de Sherbrooke, Sherbrooke, Quebec, CANADA J1K 2R1; e-mail tremblay@physique.usherb.ca; preprint also available at cond- mat@xxx.lanl.gov (#9710013).

N. V. Vo, E. W. Collings, J. O. Willis, D. E. Peterson, H. K. Liu, and S. X. Dou, "Fabrication and Characterization of High-Tc Superconducting Continuous-Tube-Forming/Filling Bi(Pb)-2223/Ag Composites and Coils." Preprint #LA-UR-97-3697; to be published in J. Amer. Ceram. Soc. Superconductivity Technology Center, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, NM 87545; telephone (505) 665-6859; telefax (505) 665-3164; e-mail nvv@lanl.gov.

Youwen Xu, J. Wurnig, M. J. Kramer, K. W. Dennis, R. W. McCallum, C. S. Schwichtenberg, and A. R. Moodenbaugh, "Superconductivity in Reduced and Then Reoxidized Nd1.05Ba1.95(Cu1-xFex)3O7-d." To be published in Physica C. Contact M. J. Kramer, Ames Laboratory-USDOE, Iowa State University, 37 Wilhelm Hall, Ames, IA 50011; telephone (515) 294-0276; telefax (515) 294-4291; e-mail mjkramer@ameslab.gov. Key words: substitution effects, structure, EELS.

Yasuji Yamada, Junichi Kawashima, Yusuke Niiori, and Izumi Hirabayashi, "Liquid Phase Epitaxy for the Production of YBa2Cu3O7-d Coated Conductor." To be published in Appl. Supercond. Nagoya Laboratory, Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 4-1 Matsuno 2-chome, Atsuta-ku, Nagoya 456, JAPAN; telephone +81 196 35 9015; telefax +81 196 35 9017.

T. Yasuda, M. Tonouchi, and S. Takano, "Influence of Self-Heating on the I-V Characteristics in Bi-2212 Intrinsic Junctions." To be published in Physica C (in press). Department of Computer Science and Electronics, Kyushu Institute of Technology, Iizuka, Fukuoka 820, JAPAN; telephone +81 948 297680; telefax +81 948 297651; e-mail yasuda@cse.kyutech.ac.jp. Key words: intrinsic Josephson effect, Bi2Sr2CaCu2Ox, single crystal. 74.50.+r; 74.72.Hs.

Joonhyun Yeo and M. A. Moore, "Non-Integer Flux Quanta for a Spherical Superconductor." Department of Physics, Kon-kuk University, 93-1 Mojin- dong, Kwangjin-gu, Seoul, 143-701, KOREA; telephone +82 2 450 3167; telefax +82 2 3436 5361; e-mail jhyeo@kkucc.konkuk.ac.kr; preprint also available at cond-mat@xxx.lanl.gov (#9710003). 74.20.De; 74.60.-w.

A. G. Zaitsev, G. Ockenfuss, and R. Woerdenweber, "Critical Thickness of YBCO Films on CeO2 Buffered Sapphire." To be published in the Proc. of the 3rd European Conf. on Appl. Supercond. (EUCAS'97), Veldhoven, The Netherlands, June 30-July 3, 1997. Institut fuer Schicht- und lonentechnik, Forschungszentrum Juelich, D-52425 Juelich, GERMANY.

COMING EVENTS (An * indicates a previously listed event.)

*Feb. 19 - 24, 1998: First International Conference on New Theories, Discoveries, and Applications of Superconductors and Related Materials (New3SC-1), Baton Rouge, La. Call for papers. Purpose of conference is to attempt to determine if "a radical change is needed in the fundamental approach to superconductivity, or if the conventional approaches are likely to bear fruit soon." Conference will focus on new ideas and measurements, concepts, and models of the mechanism and origin of high-temperature superconductivity. Discussion time will be provided throughout the conference. Subjects include superconductors, giant magnetoresistance, and ferroelectric materials. Abstract deadline, December 15, 1997. For further information, contact J. D. Fan, Chairman New3SC, P.O. Box 9767, Baton Rouge, LA 70813-9767; telephone (504) 771- 3926; telefax (504) 771-3926; e-mail new3sc@grant.phys.subr.edu; Web site http://www.phys.subr.edu/conference/new3sc.htm.

*April 19- 24, 1998: The Seventh Conference on Frontiers of Electron Microscopy in Materials Science, Kloster Irsee, Irsee, Germany. Purpose of this meeting is to establish the current state of the art of quantification of all relevant techniques used in electron microscopy including XEDS, EELS, Z-contrast, HREM, conventional TEM, CBED, and in- situ. Topical area: quantitative methods in electron microscopy. Number of participants limited to 100 (30 invited speakers, 20 invited session chairs, and 50 participants). For information, contact Kloster Irsee, Schwaebisches Tagungs- und Bildungszentrum, Klosterring 4, 87660 Irsee, Germany; telephone +49 8341 906-00; telefax +49 8341 742-78; Web site http://femms98.llnl.gov.

*May 26 - 28, 1998: 10th International Cryocooler Conference, Monterey Conference Center, Monterey, Calif. Technical program will consist of oral and poster sessions. Invited technical topics include Stirling and pulse-tube 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. Oral and poster sessions. Abstract deadline, December 12, 1997. For information, contact Peter Kittel, ICC10, MS-244-10, NASA/Ames Research Center, Moffett Field, CA 94035- 1000; telephone (650) 604-4297; telefax (650) 604-1094; e-mail pkittel@mail.arc.nasa.gov.

*June 7 - 12, 1998: European Conference on Energy Dispersive X-ray Spectrometry 1998 (EDXRS-98), Aula Prodi, San Giovanni in Monte, Bologna, Italy. Aim is to bring together experts and users of energy dispersive x-ray spectrometry working either in basic research in x-ray spectrometry, detectors and sources, or applications of x-ray spectrometry. The official language of the conference is English. Topics are: interactions of x-rays with matter and their modeling; special applications of polarized radiation (synchrotron radiation, x- ray astrophysics); conventional techniques (XRF, PIXE, sample preparation); advances in x-ray spectrometry (advanced spectrometers); data handling and instrumentation (quantitation procedures and software, x-ray sources, beam techniques); energy dispersive x-ray detectors; microanalysis with photon sources (m-XRF); microanalysis with charged particles (m-PIXE, EPMA); x-ray optics, TXRF and capillarity; specific applications (archeometry, environmental, medicine, and material testing). Preregistration deadline, November 1, 1997; abstract deadline, March 15, 1998. Selected papers presented at the conference will be printed in a special issue of the International Journal of X-Ray Spectrometry. For information, contact Barbara Cavallari, Organizing Secretariat, Laboratario delle IDEE Srl, Via S. Stefano 32, I-40125 Bologna, Italy; telephone +39 51 261440; telefax +39 51 265742; Web site http://www.ing.unibo.it/eventi/edxrs98/welcome.html.

*Sept. 13 - 18, 1998: The 1998 Applied Superconductivity Conference (ASC), Marriott's Desert Springs Resort, Palm Desert, Calif. Conference encourages contributed papers in three major areas of applied superconductivity: electronics, materials, and large-scale applications. For 1998, the theme Superconductivity -- Coming to Market., will be developed through a series of plenary and invited talks. Abstracts are solicited for papers that show a clear connection to applied superconductivity. Abstract deadline, March 9, 1998; abstract deadline for submission via the ASC Web site, March 16, 1998. Selected papers will be published in IEEE Transactions on Appl. Supercond. For information about the conference and programs for companions, contact Centennial Conferences, 4800 Baseline Rd., A-112, Boulder, CO 80303; telephone (303) 499-2299; telefax (303) 499-2599; e- mail centennial@ orci.com. For submission of abstracts or technical information, contact Ron Scanlan, Applied Superconductivity Conference, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., MS 46-161, Berkeley, CA 94720; telephone (510) 486-7241; telefax (510) 486-5310; e- mail rmscanlan@lbl.gov. Information and instructions will also be available at the Web site www.ascinc.org.

*Sept. 15 - 17, 1998: Third International Symposium on Physics and Engineering of Millimeter and Submillimeter Waves (MSMW'98), Kharkov, Ukraine. Suggested topics: wave processes in finite-size solid-state structures and HTS materials, new principles of generating and receiving millimeter and submillimeter waves, radio location and communication, remote sensing, passive and active components, antennas, and other issues. Will include all aspects of millimeter-wave HTS physics, characterization of HTS materials, and HTS-based techniques. Travel grants may be available for young scientists from the FSU and other countries. Official language is English. Proceedings to be published. Abstract deadline, April 15, 1998. For further information, contact A. Kostenko, Institute of Radiophysics and Electronics, Academy of Science of Ukraine, 12 Acad. Proskura St., 310085 Kharkov, Ukraine; telefax +380 572 441105; e-mail symposium@ire.kharkov.ua. Questions related to HTS topics may be directed to N. T. Cherpak at e-mail cherpak@ire.kharkov.ua.

High-Tc Update is the high-Tc superconductivity information exchange newsletter. Please send 1) preprints, reprints, and other research reports; 2) descriptions of on-going work; 3) meeting announcements and summaries.

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. E-mail: MITRA@AMESLAB.GOV or MITRA@IASTATE.EDU.

Project Director/Editor: Sreeparna Mitra Science Editor: John R. Clem High-Tc Update, Vol. 11, #21, November 1, 1997.