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, EPRI, and other agencies, organizations, and individuals.
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NOTA BENE:
Theory
Superconductivity recently has been reported in Sr0.4Ca13.6Cu24O41.84, which contains parallel quasi-one-dimensional Cu2O3 two-leg ladders in place of a continuous CuO2 layer. It remains a possibility that superconductivity arises from these ladders. Two preprints by N. Bulut and D. J. Scalapino (UC-Santa Barbara) investigate the superconducting gap structure in two-leg and n-leg Hubbard ladders and discuss how the gap symmetry could be determined from NMR and magnetic neutron- scattering experiments.
Using density-matrix renormalization-group (DMRG) and Monte Carlo
simulations, R. M. Noack (Wuerzburg) et al. also have examined the
dependence of pairing correlations in two-leg Hubbard ladders upon the
ratio of the inter- to intra-leg hopping t_[perp.]/t, the relative
interaction strength U/t, and the electron filling
Two papers by D. J. Scalapino (UC-Santa Barbara) discuss theoretical
aspects of pairing in the two-dimensional Hubbard model and the two-leg
Hubbard ladder. In both cases, strong short-range antiferromagnetic
correlations develop at low temperatures and lead to d_[x^2-y^2]
pairing. Two related papers by N. Bulut (UC-Santa Barbara) discuss
quantum Monte Carlo results concerning the antiferromagnetic
correlations and the low-energy excitations of the two-dimensional
Hubbard model. The author discusses the relation of these results to
NMR, neutron-scattering, and photoemission experiments on layered
cuprates.
A preprint by D. Duffy and A. Moreo (Florida State) reports quantum
Monte Carlo results for the specific heat c of the two-dimensional
Hubbard model. The authors found that c proportional to T^2 at very low
temperatures. The authors also found a low-temperature peak related to
the spin degrees of freedom and a higher-temperature broad peak related
to the charge degrees of freedom.
As discussed by S. H. Simon and P. A. Lee (MIT), the low-energy
quasiparticle excitation spectrum for a two-dimensional d-wave
superconductor in a finite magnetic field H exhibits scaling with
respect to H^[1/2]. The authors use this property to make predictions
for the scaling behavior of the specific heat, magnetic susceptibility,
optical conductivity tensor, and thermal conductivity tensor. The
results are compatible with existing experimental data.
A preprint by W. C. Wu and J. P. Carbotte (McMaster) investigates the
Raman spectra where both the incident and scattered photon polarizations
are parallel to the z direction for a plane-chain bilayer coupled via
single-particle tunneling t_[perp.]. The authors derive the Raman
vertex in the tight-binding limit and in the absence of Coulomb
screening, and find that the Raman intensity can be separated into
intraband (proportional to t_[perp.]^4) and interband (proportional to
t_[perp.]^2) transitions. In the small-t_[perp.] limit, the interband
part dominates, and a pseudogap appears, as it does in the conductivity.
The penetration depth lambda for a model of YBa2Cu3O7 involving pairing
in both the CuO2 planes and the CuO chains has been studied by X.
Leyronas and R. Combescot (ENS, Paris). In this model, pairing in the
planes is due to an attractive interaction, while in the chains Coulomb
repulsion induces an order parameter with opposite sign. This model
yields a d-wave-like order parameter, which changes sign on a single
sheet of the Fermi surface and has nodes in the gap. The anisotropy and
temperature dependence of lambda_a and lambda_b are in fairly good
agreement with experiment.
The electronic polarizability at nesting vectors of the Fermi surface
has been calculated by H.-Y. Kee (Rutgers and Bell Labs) and C. M. Varma
(Bell Labs). The authors find that a pole appears in the polarizability
at frequencies omega near the superconducting gap for arbitrarily small
coupling in two dimensions. This leads to the appearance of a sharp
peak at omega just below 2-Delta in the lattice vibrations at the
nesting vectors. The authors compare their results with recent
inelastic neutron-scattering experiments in ANi2B2C (A = Y or Lu).
A preprint by A. Mielke (Heidelberg) demonstrates how to perform a
similarity renormalization transformation to calculate an effective
Hamiltonian for the electron-phonon interaction. Using this
transformation, which avoids singularities due to degeneracies, the
author calculates the effective electron-electron interaction to second
order in the electron-phonon coupling. The resulting effective
interaction between two electrons forming a Cooper pair is attractive in
the whole parameter space. The author uses a simple Einstein model to
calculate the renormalized electron energies and the superconducting
critical temperature Tc.
The effect of Pauli paramagnetism on the properties of unconventional
superconductors with d_[x^2-y^2] pairing has been examined by K. V.
Samokhin (Koeln and Landau Institute). The author finds that if the
Pauli term is sufficiently large, the phase transition goes from the
normal state to a strip-like, spatially modulated superconducting state,
which is analogous to the Larkin-Ovchinnikov-Fulde-Ferrell state in
conventional superconductors.
Vortices
Finite-temperature effects on the vortex system in a high-temperature
superconductor have been studied by H. Nordborg and G. Blatter (ETH-
Zurich) using the mapping to 2D bosons and the path-integral Monte Carlo
method. With increasing temperature at fixed magnetic field, the
authors find a single first-order transition from an Abrikosov lattice
directly to an entangled vortex liquid. That is, for thick samples,
they do not obtain a two-stage melting transition, first from a lattice
to a disentangled line liquid and then to an entangled liquid. The
transition is characterized by an entropy jump of Delta-S ~~ 0.27 k_B
per degree of freedom and a Lindemann number c_L ~~ 0.29. At low
fields, when the London penetration depth lambda is about equal to the
intervortex spacing, the vortex density at constant applied field is
reduced by Delta-rho/rho ~~ 0.0003 upon melting.
The phase diagram of layered superconductors has been explored by A. E.
Koshelev (Argonne and ISSP-Chernogolovka) using Monte Carlo simulations
of the three-dimensional uniformly frustrated XY model. The author
found two regimes of behavior depending on the anisotropy. At high
anisotropy, melting of the vortex lattice occurs as a strong first-order
phase transition (entropy jump Delta-S ~~ 0.3-0.4 k_B per pancake
vortex), accompanied by the destruction of vortex lines, the appearance
of a pancake liquid, and the disappearance of superconductivity along
the field direction. At low anisotropy, melting occurs as a weaker
first-order phase transition (Delta-S < 0.05 k_B/pancake) first into a
liquid of vortex lines (pancake vortices in adjacent layers aligned with
each other) with superconductivity along the field direction.
Dynamic phase transitions in a driven vortex lattice subject to quenched
disorder have been investigated by I. Aranson (Bar Ilan and Argonne) et
al. using numerical simulations of the time-dependent Ginzburg-Landau-
Lawrence-Doniach equations. The authors considered a bilayered system
as a prototype of multilayered current-carrying superconductors. Two
distinct phase transitions were found: a dynamic melting transition,
similar to that found in a single-layer system, and a decoupling
transition, which occurs only in a multi-layered system. Since these
two transitions depend differently upon the shaking temperature and the
renormalized interlayer coupling, the phase diagram shows four possible
regions: aligned vortex crystal, aligned vortex liquid, decoupled
vortex crystal, and decoupled vortex liquid.
The Hamiltonian for two- and three-dimensional inductive Josephson-
junction arrays has been derived by R. Sasik et al. (Los Alamos). The
variables to describe the system are the gauge-invariant phase
differences across the junctions.
A preprint by P.H.E. Tiesinga (Utrecht) et al. reports numerical studies
of the dynamic correlation functions in thermodynamic equilibrium of
two-dimensional models with either bond (RSJ) or site (TDGL) dissipation
as a function of temperature. The authors found that the TDGL results
are in closer agreement with experiments in Josephson-junction arrays.
The results are related to anomalous vortex diffusion through vortex
clusters.
The behavior of clean layered superconductors in the presence of a
finite electrical current in zero magnetic field is addressed in a
preprint by S. W. Pierson (WPI). The author identifies four distinct
regions of the current-temperature phase diagram and describes the
behavior in each of these.
A phenomenological model of vortex dynamics in type-II superconductors
in the presence of a transport current and a temperature gradient has
been developed by V. M. Krasnov (ISSP-Chernogolovka) and G. Yu. Logvenov
(ISSP-Chernogolovka and Erlangen). The authors include the effects of
Magnus, Lorentz, thermal-drag, viscous-damping, and pinning forces.
A preprint by P. Ao (Umea) uses a vortex equation of motion and the two-
fluid model to demonstrate that in the presence of pinning, a simple
relation exists between the Nernst and Seebeck coefficients and the
resistivity tensor. A combination of electric and thermoelectric
transport experiments can be used to test the basic models for vortex
dynamics in superconductors. The author finds that a vortex dynamics
model without various normal-fluid drag forces is consistent with
experiment, while an alternative model with those drag forces is not.
RBa2Cu3O7-d
The transverse Peltier effect has been investigated by Z. H. He
(Zhongshan University) et al. on top-seeded melt-textured YBa2Cu3O7-d
(YBCO). The results support the idea that the off-diagonal
thermoelectric effect is responsible for the anomalously high laser-
induced transient transverse voltages observed in c-axis-oriented YBCO
superconducting thin films.
The in-plane rho_[ab] and out-of-plane rho_c resistivities of Y1-
xPrxBa2Cu3O7-d have been determined by C. N. Jiang (Kent State) et al.
using the electrical contact configuration of the dc flux transformer.
The x dependencies of rho_[ab] and rho_c, together with the coexistence
of a metallic rho_[ab] and a semiconducting rho_c, are consistent with
the presence of a gap in the energy spectrum of the CuO chains,
supporting the idea that the c-axis transport is dominated by tunneling
through both valence and conduction bands of the CuO chains.
Bi Cuprates
Using a high-resolution magneto-optical technique, T. B. Peterson
(Argonne) et al. have studied the flow of transport currents around
cracks in monofilament (Bi,Pb)2Sr2Ca2Cu3O10+d composite conductors. The
authors observe shunting through the Ag cladding, and they find that the
current in the silver decays exponentially with distance from the crack,
as expected in a one-dimensional distributed resistance model. At 77 K,
the decay length is approximately 0.4 mm, implying an interface
resistivity of 4 x 10^[-8] ohm-cm^2. The decay length increases with
increasing temperature.
Measurements of the dc magnetization of Bi2Sr2CaCu2O8+d in magnetic
fields H tilted at an angle theta relative to the c axis are reported by
Y. Yamaguchi (ETL) et al. As the field increases through the second-
peak field H_[p2], the behavior at 30 K indicates a crossover from
three-dimensional to two-dimensional coupling of vortices.
Other Cuprates
A 50 K enhancement of Tc as the pressure is increased over a span of 20
GPa is reported by C. Acha et al. (Grenoble) in the compound Hg2Ba2(Y1-
xCax)Cu2O8-d. Different Ca doping levels were found to give different
initial Tc's but to yield the same strong pressure dependence. The
authors suggest that the large Tc increase with pressure for all the Hg-
based compounds, independent of doping level, indicates the existence of
a common structural parameter, whose identification should be a guide
for future synthesis efforts of high-Tc materials.
The excess oxygen content and hole concentration in 110^oC-annealed
La2CuO4+d (0 < d < 0.12) prepared by electrochemical oxidation have been
studied by Z. G. Li et al. (TCSUH). The authors observed two distinct
O-doping sites, with efficiencies of 2 and 1.3 holes per excess oxygen
atom, respectively. The occupation of the two different sites is
determined by a critical carrier concentration P_c ~~ 0.06, suggesting a
sudden increase in the chemical potential of doped holes at P_c.
The synthesis of new ceramic quadruple-perovskite layered cuprates
NdBa3Cu2Ti1+xNb1-xO11 and Nd2Ba2Cu2Ti2-xMxO11 (M = Mn, Fe, Co, and Al)
is reported by T. Rentschler (Hamburg). Rietveld refinements revealed
an oxygen-deficient layered (a_p,a_p,4a_p) superstructure with space
group P4/mmm. Although the incorporation of the substituted elements
was verified, p-type doping of the CuO2 layers was not indicated by
their thermochemical or physical properties, and superconductivity was
not observed. Although these materials have the CuO2 layers in common
with the high-Tc superconductors, evidently the quadruple perovskites
are not susceptible to the creation of mixed valency.
A preprint by A. T. Matveev (NIRIM) et al. reports two new members (n =
4 and 6) of the homologous series (GezCu1-z)Sr2Can-1-xYxCunOy. The
superconducting Tc's of these materials are 89 K for n = 4 and 78 K for
n = 6.
Thin Films
As reported by J. Lesueur (Orsay) et al., all in-situ YBCO/Pb and
YBCO/Ag/Pb planar tunnel junctions with very low-leakage I-V
characteristics have been made on c-axis-oriented YBCO thin films grown
by a co-evaporation technique. The junctions are hysteretic and display
a Josephson current below 7.2 K (Tc of Pb). The only modification
introduced by Ag is a substantial lowering of the normal-state
resistance R_n, but the I_cR_n product remains roughly constant. The
magnetic-field modulation of I_c indicates a rather homogeneous current
distribution over the whole junction area (0.5 mm^2) and obeys the
expected behavior for a short Josephson junction on a thin film
(thickness < lambda_[ab]). The observed Josephson coupling between a
conventional superconductor and the high-Tc compound along its c axis
indicates that an s-wave component is present in YBCO's superconducting
order parameter.
The inelastic component of the differential conductivity of YBa2Cu3O7-
d/Au point-contact tunnel junctions has been studied experimentally and
theoretically by M. Grajcar (Jena and Bratislava) et al. The authors
found both linear (proportional to |V|) and quadratic (proportional to
|V|V) components of the differential conductivity as a function of the
bias voltage V. The sign of the quadratic term was found to depend on
both the sign of the bias voltage and the ratio of the Fermi energy to
the tunneling barrier strength, leading to asymmetry of the
characteristics even if the barrier is rectangular. The authors find
good agreement between experiment and their theory.
A (Bi2Sr2Ca4Cu5O14)(Bi2Sr2CuO6) [(Bi-2245)(Bi-2201)] superlattice film
synthesized by sequential sputtering on an MgO single crystal (001)
substrate has been studied by T. Hatano et al. (NRIM) using x-ray-
diffraction, magnetization, and Hall-effect measurements. The
superconducting transition temperature Tc of the superlattice film (41
K) was found to be higher than those of the Bi-2245 (10 K) and Bi-2201
(< 2K) single-phase films. The authors explain the Tc enhancement of
the superlattice in terms of charge transfer from the overdoped Bi-2201
units to the underdoped Bi-2245 units.
The growth of biaxially textured buffer layers on rolled Ni substrates
by electron-beam evaporation is described in a preprint by M.
Paranthaman et al. (Oak Ridge). The Ni substrates were prepared using
the concept of rolling-assisted biaxially textured substrates (RABiTS).
Two buffer-layer architectures are described: CeO2/Pd/Ni and
YSZ/CeO2/Ni. The authors found that the layer thickness was critical;
for some thicknesses, cracks formed in the CeO2 layer.
As reported by A. Odagawa (Matsushita Electric Industrial, Kyoto) et
al., intrinsic (interlayer) Josephson junctions have been observed in
(Bi,Pb)2Sr2Ca2Cu3O10+d thin films. The authors fabricated mesa
structures on the surface of high-quality films prepared by rf
sputtering and subsequent heat treatment. The junctions showed
hysteresis and a multiple branching structure with periodic voltage
jumps. The results demonstrate that the mesas consist of stacked SIS
junctions in series. From this periodic structure, the authors obtained
a voltage jump of 26-28 mV for the 2223 phase at 4.2 K.
The standard method of step formation for a high-Tc step-edge Josephson
junction involves ion milling of a substrate and thus results in damage
to the substrate surface in the etched area. A new approach for the
fabrication of high-Tc step-edge junctions without etching is described
in a preprint by G. A. Ovsyannikov (IREE, Moscow) et al. The authors
produced step-edge Josephson junctions at steps in epitaxial CeO2 layers
grown on NdGaO3 and on R-plane sapphire with a CeO2 buffer layer. The
steps were formed on the substrate by deposition of CeO2 layers at high
temperature (770^oC) using a micromask technique. YBCO thin-film
bridges grown across the step were observed to exhibit selective
Josephson detector response and Shapiro steps under microwave
irradiation.
Bilayer thin films of a ferromagnetic material (permalloy, Ni0.8Fe0.2)
and YBa2Cu3O7-d separated by a thin Au diffusion barrier have been used
by D. B. Chrisey (NRL) et al. to investigate the effects of spin-
polarized quasiparticle injection on the order parameter. A thin strip
of YBa2Cu3O7-d was patterned, and two pairs of Au cross strips for
current and voltage contacts were deposited at each end. Between these
contacts, permalloy and Au cross strips were deposited to serve as spin-
polarized and unpolarized quasiparticle injection sources, respectively.
Using this pseudo-three-terminal device configuration, the authors
observed in some samples that injection of spin-polarized quasiparticles
into YBCO produced a much stronger suppression of the order parameter
than did injection of unpolarized quasiparticles.
The superconducting properties of ion-beam-modified YBCO microbridges on
SrTiO3 substrates have been investigated by F. Schmidl et al. (Jena).
Microbridges of width 10 micrometers were irradiated through slits in a
700 nm thick double-layer resist mask using 30 keV or 100 keV O^+ ions
with doses in the range 10^[13]-10^[14] ions/cm^2. A related paper by
H. Schneidewind et al. (Jena) reports on the use of ion-beam etching to
prepare superconducting structures and then to further tune their
characteristics. This process was used to modify Josephson junctions in
dc SQUIDs after preparation to adjust them to special working
conditions.
Electromigration effects have been observed by K. Herrmann (Karlsruhe)
et al. in electron-beam-damaged YBCO junctions. The authors found that
electromigration occurs during the application of dc bias currents with
current densities around 1 x 10^6 A/cm^2 at room temperature. The data
can be explained by a rearrangement of oxygen in the chains during
electromigration, while the junction properties are mostly determined by
oxygen vacancies and interstitials in the planes.
Applications
The development of a one-channel high-Tc dc SQUID heart-monitoring
system for noninvasive measurements in an unshielded environment is
reported by R. Weidl et al. (Jena). The authors prepared planar
galvanically coupled thin-film gradiometers and magnetometers with step-
edge and bicrystal junctions. These sensors were used to perform
magnetocardiogram measurements in a magnetically shielded room with open
doors and in an unshielded environment. The authors suggest that such
systems can give fast and reliable information about heart conditions in
emergency cases.
The effect of eddy current dampers on the vibrational properties in
superconducting levitation using melt-processed YBCO superconductors has
been investigated by H. Teshima (Nippon Steel) et al. The authors found
that, in vertical vibration, the damping was improved by a factor of 100
by inserting eddy current dampers into the gap between the
superconductor and the magnet. In horizontal vibration, on the other
hand, the eddy current dampers did not have a significant effect.
As reported by M. Ullrich et al. (Goettingen), thermal cycling reduces
the levitation force of melt-textured YBCO. The authors report that
this is caused by the generation and propagation of cracks, which
decrease the effective radii of screening currents and thereby the
magnetic moment and the levitation force. The authors measured the
mechanical properties of melt-textured YBCO and found that the fracture
toughness K_[IC] and the hardness H_v are low.
Other Activities
The ac response of thin, narrow high-Tc rings has been investigated by
M. Mrovka (Leipzig) et al. at ac and dc fields less than 1 mT. The ac
susceptibility as a function of reduced ac field h/h_m, where h_m is the
ac field at the dissipation maximum, was found to be temperature-
independent and to be well described by a model presented by the
authors.
Sr2Cu3O4Cl2, a nonsuperconducting tetragonal variant of the lamellar
cuprates, contains an extra Cu^[2+] ion in the center of every second
plaquette of the square CuO2 lattice. The two types of Cu form
interpenetrating Heisenberg antiferromagnets, which order at 380 K and
40 K. Magnetization measurements by F. C. Chou (MIT) et al. reveal a
small spontaneous ferromagnetic moment below 380 K and two spin-rotation
transitions. The authors explain the results in detail in terms of a
pseudo-dipolar coupling between the two Cu lattices. A quantitative
analysis of the data also yields several previously unknown microscopic
coupling constants, which are relevant to other lamellar, chain, and
ladder copper oxides.
Overviews
A review of the materials chemistry and thermodynamics of the RBa2Cu3O7-
d (R = rare earth) series of superconductors has been prepared by J. L.
MacManus-Driscoll (Imperial). The author discusses the importance of
this basic information for predicting and controlling structure and
microstructure of single crystals, thin films, and bulk materials. She
presents examples of where an understanding of thermodynamics has led to
advances in processing, and she highlights future areas of research that
are key to the second decade of superconductor processing (209 refs.).
The current state of Josephson junctions in high-temperature
superconductors (HTS) and the prospects for applications at microwave
frequencies are reviewed by G. A. Ovsyannikov (IREE, Moscow). The
author discusses Josephson junction arrays as microwave generators, HTS
Josephson receivers, Josephson detectors, Hilbert-transform
spectrometers, Josephson parametric amplifiers, and microwave mixers (44
refs.).
Structural and magnetic neutron-scattering studies of single crystals of
La2CuO4+y containing excess oxygen in interstitial sites are reviewed by
B. O. Wells (MIT) et al. For low oxygen contents, macroscopic phase-
separation takes place below room temperature in which the material
phase-separates into an oxygen-rich superconducting phase and an oxygen-
poor antiferromagnetic phase. Inelastic neutron-scattering experiments
reveal incommensurate spin fluctuations, similar to those in La2-
xSrxCuO4, in samples at the oxygen-rich edge of the main miscibility gap
(28 refs.).
Ph.D. Thesis
The Ph.D. thesis of M. Houssa (Liege) is devoted to the theory of the
thermal conductivity of high-Tc superconductors. The author analyzes
the magnetic-field dependence of the thermal conductivity and finds, in
comparing with experiment, that the peak in the in-plane thermal
conductivity below Tc is of electronic origin. The author also finds
strong support in the data for an energy-gap parameter with d_[x^2-y^2]-
wave symmetry (278 refs.).
Contributed by John R. Clem
Contents: Technology News is on page 6; Preprints begin on page 6;
Coming Events begin on page 12; FYI is on page 13.
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.
*Researchers Seek Collaboration: Magnetic systems with nonaxially
symmetric fields up to 5 T and high spatial homogeneity have been
developed at the Institute of Radiophysics and Electronics (IRE) of the
National Academy of Sciences, Kharkov, Ukraine, using NbTi
superconducting solenoids inside ferromagnetic screens. The magnets are
applied in solid-state maser amplifiers and microwave spectroscopy
applications (T = 1.7-4.2 K). The researchers are interested in
developing similar HTS solenoid systems for ESR and FMR-spectroscopy and
other applications, and would like to collaborate with groups that have
successfully developed wires with the following characteristics: Jc >=
10^4 A/cm^2 (77 K), diameter ~ 0.1 mm, and length > 100 m. Contact N.
T. Cherpak, Institute of Radiophysics and Electronics (IRE), National
Academy of Sciences, 12 acad. Proskura str., 310085 Kharkov, Ukraine;
telephone +38 0 572-448-363; telefax +38 0 572 441-105; e-mail
ire@ire.kharkov.ua. *Previously run entry with corrected phone and fax
numbers, and additional e-mail information.
Contributed by Sreeparna Mitra
_________________________________________________________________________
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.
M. V. Abrashev, C. Thomsen, V. N. Popov, and L. N. Bozukov, "Raman
Spectroscopy and Lattice-Dynamics Calculations of Mixed Layered Copper-
Titanium Oxides." To be published in Physica C (in press). Institut
fuer Festkoerperphysik, Technische Universitaet Berlin,
Hardenbergstrasse 36, D-10623 Berlin, GERMANY. Key words: copper-
titanium oxides, Raman spectroscopy, lattice dynamics.
C. Acha, S. M. Loureiro, C. Chaillout, J. L. Tholence, J. J. Capponi, M.
Marezio, and M. Nunez-Regueiro, "50 K Enhancement of Tc by Pressure in
the Hg-2212 Superconductor." To be published in Solid State Commun.
Centre de Recherches sur les Tres Basses Temperatures, C.N.R.S., 25
Avenue des Martyrs, BP 166 Cedex 09, F-38042 Grenoble, FRANCE; telephone
+33 4 76 88 78 38; telefax +33 4 76 87 50 60; e-mail
acha@labs.polycnrs-gre.fr.
Key words: high-Tc superconductors, x-ray scattering,
electronic transport, phase transitions, high pressure.
*P. Ao, "Nernst Effect, Seebeck Effect, and Vortex Dynamics in the Mixed
State of Superconductors." Department of Theoretical Physics, Umea
University, S-90187 Umea, SWEDEN; e-mail ao@tp.umu.se. 74.25.Fy;
74.60.Ec; 74.60.Ge. *Revised manuscript.
P. R. Apte, V. V. Srinivasu, and R. Pinto, "Penetration Depth
Measurement near Tc in YBa2Cu3O7-d Thin Films: Role of Classical
Fluctuations in Order Parameter Phase." To be published in the Proc. of
the Int. Symp. on Advances in Superconduc.: New Materials, Critical
Currents and Devices, (ASMCCD '96), Mumbai, India, Sept. 17-20, 1996.
Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai
400 005, INDIA; V. V. Srinivasu's telefax +91 22 215 2110; e-mail
vvs@tifrvax.tifr.res.in.
I. Aranson, A. Koshelev, and Valerii Vinokur, "Phase Diagram for Driven
Vortex Lattice in Layered Superconductors." Submitted to Phys. Rev.
Lett. 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; 68.10.-m; 05.60.+w.
C. Aruta, G. Balestrino, S. Martellucci, A. Paoletti, and G. Petrocelli,
"Artificially Layered Films of CuBa2(Ca1-xSrx)n-1CunOy Grown Using
Pulsed Laser Deposition." To be published in J. Appl. Phys. INFM,
Dipartimento di Scienze Fisiche, Universita di Napoli "Federico II,"
Piazzale Tecchio 80, I-80125 Napoli, ITALY.
E. Babic, I. Kusevic, P. Simundic, M. Ionescu, H. K. Liu, and S. X. Dou,
"Jc-B-T Surfaces of Ag-Clad Bi-Based Tapes." Presented at the Eighth
Int. Workshop on Critical Currents in Supercond. (8th IWCC), Kitakyushu,
Japan, May 27-29, 1996. Department of Physics, Faculty of Science,
University of Zagreb, Bijenicka c. 32, P.O.B. 162, HR-10000 Zagreb,
CROATIA; telephone +385 1 455 5730; telefax +385 1 432 525; e-mail
ebabic@phy.hr. Key words: critical currents, flux pinning and creep,
BSCCO/Ag tapes.
G. Backx and J. O. Indekeu, "Depinning Transition of the
Superconducting/Normal Interface in Low-kappa Twinning-Plane
Superconductors: Interface Potential and Interface Displacement." To
be published in Physica C (in press). Contact J. O. Indekeu,
Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke
Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, BELGIUM.
05.70.Fh; 05.70.Jk; 64.60.Fr; 68.35.Rh.
D. Berling, A. Mehdaoui, B. Loegel, G. Leggieri, M. Luisa De Giorgi, A.
Luches, A. Del Vecchio, and L. Tapfer, "ac Susceptibility Measurements
of Films with Different Structural Qualities." Published in J. Alloys &
Compounds. Laboratoire de Physique et de Spectroscopie Electronique,
URA CNRS 1345, Facult des Sciences et Technique, Universit de Haute
Alsace, 4 rue des Freres Lumiere, F-68093 Mulhouse Cedex, FRANCE;
telephone +33 89 59 63 40.
Howard A. Blackstead and John D. Dow, "Flux-Pinning by Ba-Site Magnetic
Rare-Earth Ions in (Rare-Earth)1+uBa2-uCu3Ox Compounds." Ref. No.
pin215.rno. Department of Physics, University of Notre Dame, Notre
Dame, IN 46556; telephone (219) 631-7078; telefax (219) 631-5952; e-mail
blackstd@rems1.phys.nd.edu. Key words: superconductivity, rare earths.
74.20.Fg.
N. Bulut, "Low-Energy Electronic Excitations of the Layered Cuprates and
the Hubbard Model." Department of Physics, University of California,
Santa Barbara, CA 93106-9530; telephone (805) 893-2246; telefax (805)
893-8838; e-mail nejat@spock.physics.ucsb.edu; preprint also available
at cond-mat@xxx.lanl.gov (#9606204).
N. Bulut, "Short-Range Antiferromagnetic Correlations and the
Photoemission Spectrum." Department of Physics, University of
California, Santa Barbara, CA 93106-9530; telephone (805) 893-2246;
telefax (805) 893-8838; e-mail nejat@spock.physics.ucsb.edu; preprint
also available at cond-mat@xxx.lanl.gov (#9606198).
N. Bulut and D. J. Scalapino, "Determining the Structure of the
Superconducting Gap in Cu2O3 2-Leg Ladder Materials." Department of
Physics, University of California, Santa Barbara, CA 93106-9530;
telephone (805) 893-2246; telefax (805) 893-8838; e-mail
nejat@spock.physics.ucsb.edu; preprint also available at cond-
mat@xxx.lanl.gov (#9609127).
N. Bulut and D. J. Scalapino, "Weak-Coupling Calcuation of the Gap
Structure of Doped n-Leg Hubbard Ladders." Department of Physics,
University of California, Santa Barbara, CA 93106-9530; telephone (805)
893-2246; telefax (805) 893-8838; e-mail nejat@spock.physics.ucsb.edu;
preprint also available at cond-mat@xxx.lanl.gov (#9609136).
G. C. Che, Z. X. Zhao, J. W. Li, H. Chen, C. Dong, and S. L. Jia,
"La1.6Sr0.4CaCu2O4+dCl2-y Superconductor Synthesized at Ambient
Pressure." To be published in Physica C (in press). Institute of
Physics, Chinese Academy of Science, National Laboratory for
Superconductivity, Beijing 100080, PEOPLE'S REPUBLIC OF CHINA; telefax
+86 1 256 2605; e-mail shx@aphy01.iphy.ac.cn.
D.-X. Chen, K.-Y. Wang, and A. Hernando, "Critical-State Calculation
Using Arbitrary Functional Jc and Annealing Effect on Sintered
YBa2Cu3O7-d Superconductor." To be published in Physica C (in press).
Instituto de Magnetismo Aplicado, RENFE-UCM, 28230 Las Rozas, Madrid,
SPAIN. 74.25.Ha; 74.60.Jg.
F. C. Chou, Amnon Aharony, R. J. Birgeneau, O. Entin-Wohlman, M. Greven,
A. B. Harris, M. A. Kastner, Y. J. Kim, D. S. Kleinberg, Y. S. Lee, and
Q. Zhu, "Ferromagnetic Moment and Spin Rotation Transitions in
Tetragonal Antiferromagnetic Sr2Cu3O4Cl2." Center of Materials Science
and Engineering, Massachusetts Institute of Technology, Cambridge, MA
02139. 05.70.Fh; 75.10.Jm; 75.25.+z; 75.30.Cr; 75.50.Ee.
D. B. Chrisey, M. S. Osofsky, J. S. Horwitz, R. J. Soulen, B. Woodfield,
J. Byers, G. M. Daly, P. C. Dorsey, J. M. Pond, M. Johnson and R.C.Y.
Auyeung, "Evidence for Modification of the Superconducting Order
Parameter in YBa2Cu3O7-d Films by Injection of a Spin Polarized
Current." Presented at the Applied Superconductivity Conference,
Pittsburgh, PA, Aug. 25-30, 1996; to be published in IEEE Trans. Appl.
Supercond. Code 6672, Naval Research Laboratory, Washington, DC 20375-
5345.
X. T. Cui, J. R. Liu, Z. H. Zhang, Q. Y. Chen, and W. K. Chu, "Low
Temperature Ion Channeling in YBCO Films Grown on MgO Substrate."
Preprint #96:159; submitted to the Proc. of the 14th Int. Conf. on the
Application of Accelerators in Research and Industry, Denton, TX, Nov.
6-9, 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.
Daniel Duffy and Adriana Moreo, "Specific Heat of the 2D Hubbard Model."
Submitted to Phys. Rev. B. Department of Physics, National High
Magnetic Field Lab and MARTECH, Florida State University, 1800 E. Paul
Dirac Dr., Tallahassee, FL 32306-4005; telephone (904) 644-0530; telefax
(904) 644-0867. 65.40.+g; 65.50.+m; 75.40.Cx; 75.40.Mg.
A. Fartash, "In-Plane Orientational Order Across C60(111)/Au(111)
Interfaces." Preprint #96.158; submitted to J. Appl. Phys. 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.
Mikhail V. Fistul and Gabriele F. Giuliani, "Generalized Eck Peak in
Inhomogeneous Josephson Junctions." To be published in Physica C (in
press). Contact Gabriele F. Giuliani, Department of Physics, Purdue
University, 1396 Physics Building, West Lafayette, IN 47907-1396;
telefax (317) 494-0706. Key words: Josephson effect, flux lattice.
Ryoji Funahashi, Ichiro Matsubara, Toru Ogura, Kazuo Ueno, and Hiroshi
Ishikawa, "Critical Current Density for Bi2Sr2CaCu2Ox/Ag Tapes Prepared
Using an Isothermal Partial Melting Method Under Controlled
Atmospheres." To be published in Physica C (in press). Osaka National
Research Institute, AIST, Midorigaoka, Ikeda, 563 Osaka, JAPAN; telefax
+81 727 51 9622; e-mail fune@onri.go.jp. Key words: critical current
density, Bi2Sr2CaCu2Ox/Ag tapes, isothermal partial-melting method,
soldification time.
Miroslav Grajcar, Andrej Plecenik, Paul Seidel, Viktor Vojtanik, and
Kai-Uwe Barholz, "Asymmetry and Quasi-Linear Background of Differential
Conductance Characteristics of HTS/Metal Tunnel Junctions." Preprint
No. HEP/123-qed; submitted to Phys. Rev. B. Institut fuer
Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Lessingstr. 8,
D-07743 Jena, GERMANY; Paul Seidel's telephone +49 3641-635685 or
-635681; telefax +49 3641-635681; e-mail seidel@ifk.uni-jena.de.
73.40.Gk; 73.40.Rw; 74.80.Fp.
Takeshi Hatano, Akira Ishii, and Keikichi Nakamura, "Synthesis and
Superconductivity of a (Bi2Sr2Ca4Cu5O14)1(Bi2Sr2CuO6)1 Superlattice
Film." To be published in Physica C (in press). National Research
Institute for Metals, 1-2-1 Sengen, Tsukuba, 305 Ibaraki, JAPAN; telefax
+81 298 53 1019; e-mail hatano@nrim.go.jp. Key words: Bi-based
compounds (Bi2Sr2Can-1CunO4+2n), hole concentration, thin films,
multilayers.
Z. H. He, Z. G. Ma, Q. Y. Li, Y. Y. Luo, J. X. Zhang, R. L. Meng, and C.
W. Chu, "Investigation of Transverse Peltier Effect on Top-Seeded Melt
Texture YBa2Cu3O7-d ." Preprint #96:155; to be published in Appl. Phys.
Lett. Department of Physics, Zhongshan University, Guangzhou 510275,
PEOPLE'S REPUBLIC OF CHINA; e-mail stshzh@zsulink.zsu.edu.cn; preprint
also available from 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. Herrmann, A. J. Pauza, F. Baudenbacher, J. S. Santiso, and D. F.
Moore, "Electromigration Effects in e-beam Junctions." To be published
in Physica C. Forschengszentrum Karlsruhe, INFP, P. O. Box 3640, D-
76021, Karlsruhe, GERMANY; telephone +49 7247 823284; telefax +49 7247
824624; e-mail k.herrmann@infp.fzk.de. Key words: electromigration,
Josephson effect, thin films, applications of high-Tc superconductors.
Michel Houssa, "Theory of the Thermal Conductivity of High-Tc
Superconductors." Submitted as a Ph.D. thesis (University of Liege,
1996). SUPRAS, Department of Solid State Physics, Institute of Physics
B5, University of Liege, B-4000 Liege, BELGIUM; telephone +32 4 366
3703; telefax +32 4 366 2990; e-mail houssa@gw.unipc.ulg.ac.be.
C. N. Jiang, A. R. Baldwin, G. A. Levin, T. Stein, C. C. Almasan, D. A.
Gajewski, S. H. Han, and M. B. Maple, "Nonmonotonic Evolution of Out-of-
Plane Resistivity with Pr Doping in Y1-xPrxBa2Cu3O7-d Single Crystals."
To be published in Phys. Rev. B. Contact C. C. Almasan, Department of
Physics, Kent State University, Kent, OH 44242; telephone (330) 672-
2402; telefax (330) 672-2959; e-mail calmasan@physics.kent.edu.
74.25.Fy; 74.72.Bk.
Hae-Young Kee and C. M. Varma, "Singularities in the Polarizability of
Superconductors at Nesting Vectors." Department of Physics, Rutgers
University, Piscataway, NJ 08855-0849; e-mail
hykee@physics.rutgers.edu; preprint also available at cond-
mat@xxx.lanl.gov (#9611212). 74.20.-z; 74.25.Kc.
Z. Klencsar, E. Kuzmann, A. Vertes, J. Bankuti, T. Racz, M. Bodog, and
I. Kotsis, "Mossbauer Study of Effect of Substitution of Pr in Eu-
Containing High Temperature Superconductor." To be published in Physica
C (in press). Contact E. Kuzmann, Department of Nuclear Chemistry,
Eoetvoes University, Budapest, HUNGARY.
A. E. Koshelev, "Probing of the Phase Diagram of Layered High Tc
Superconductors by Monte Carlo Simulations." To be published in the
Proc. of the 9th Int. Symp. on Supercond. (ISS'96), Sapporo, Hokkaido,
Japan, Oct. 21-24, 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. Key words: layered
superconductors, vortex lattice melting, phase diagram.
V. M. Krasnov, A. E. Kovalev, V. A. Oboznov, and N. F. Pedersen,
"Magnetic Field Decoupling and 3D-2D Crossover in Nb/Cu Multilayers."
To be published in Phys. Rev. B. Department of Physics, Chalmers
University of Technology, S-41296 Goeteborg, SWEDEN. 74.80.Dm;
74.50.+r.
V. M. Krasnov and G. Yu. Logvenov, "Self-Consistent Analysis of Magnus
and Thermal Forces Acting on Vortices in Type-II Superconductors." To
be published in Physica C. Department of Physics, Chalmers University
of Technology, S-41296 Goeteborg, SWEDEN.
I. Kusevic, P. Simundic, E. Babic, J. Ivkov, Z. Marohnic, M. Ionescu, H.
K. Liu, and S. X. Dou, "Jc-B-T Surface of High-Jc Bi2Sr2CaCu2O8+x/Ag
Tape." To be published in Supercond. Sci. Tech. Contact E. Babic,
Department of Physics, Faculty of Science, University of Zagreb,
Bijenicka c. 32, P.O.B. 162, HR-10000 Zagreb, CROATIA; telephone +385 1
4555730; telefax +385 1 432525; e-mail ebabic@phy.hr. Key words:
critical currents, flux pinning and creep, BSCCO/Ag tapes. 74.60.Ge;
74.60.Jg; 74.72.Hs.
J. Lesueur, M. Aprili, A. Goulon, T. J. Horton, and L. Dumoulin,
"Evidence for a Josephson Tunnel Current in all in-situ c-YBCO/Pb
Junctions." To be published in Phys. Rev. B. C.S.N.S.M. CNRS-IN2P3
Bat. 108, Universite Paris-Sud, F-91405 Orsay, FRANCE. 74.50.+r;
74.72.Bk.
X. Leyronas and R. Combescot, "Plane-Chain Coupling in YBa2Cu3O7:
Temperature Dependence of the Penetration Depth." Laboratoire de
Physique Statistique, Ecole Normale Superieure, 24 Rue Lhomond, F-75231
Paris Cedex 05, FRANCE; R. Combescot's e-mail
roland.combescot@lps.ens.fr; preprint also available at cond-
mat@xxx.lanl.gov (#9612145). 74.20.Fg; 74.72.Bk; 74.25.Jb.
Jian-Xin Li and Chang-De Gong, "Magnetic and Charge Transport Properties
in Underdoped YBa2Cu3O6+x and YBa2Cu4O8." To be published in Physica C
(in press). National Laboratory of Solid State Microstructures,
Institute for Solid Physics, Nanjing University, Nanjing 210093,
PEOPLE'S REPUBLIC OF CHINA. 74.20.Hi; 74.25.Fy; 74.72.Bk.
Z. G. Li, H. H. Feng, Z. Y. Yang, A. Hamed, S. T. Ting, P. H. Hor, S.
Bhavaraju, J. F. DiCarlo, and A. J. Jacobson, "Carrier-Controlled Doping
Efficiency in La2CuO4+d." Preprint #96:153; to be published in Phys.
Rev. 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. 74.25.Bt; 74.25.-q; 74.72.Dn.
J. L. MacManus-Driscoll, "Materials Chemistry, Thermodynamics and
Processing of ReBa2Cu3O7-x." To be published in Adv. Mater. Department
of Materials and Center for High Temperature Superconductivity, Imperial
College, Prince Consort Rd., London SW7 2BP, UNITED KINGDOM; telephone
+44 171 594 6749; telefax +44 171 584 3194; e-mail j.driscoll@ic.ac.uk.
J. L. MacManus-Driscoll, Y. H. Li, and Z. Yi, "The Upper Phase Stability
Limit of Bi-2212." To be published in J. Amer. Ceram. Soc. Department
of Materials and Center for High Temperature Superconductivity, Imperial
College, Prince Consort Rd., London SW7 2BP, UNITED KINGDOM; telephone
+44 171 594 6749; telefax +44 171 584 3194; e-mail j.driscoll@ic.ac.uk.
A. T. Matveev, J. Ramirez-Castellanos, Y. Matsui, and E. Takayama-
Muromachi, "New High-Tc Superconductors (GezCu1-z)Sr2Can-1-xYxCunOy
(n=4,6) Prepared at High Pressure." To be published in Physica C (in
press). Contact E. Takayama-Muromachi, National Institute for Research
in Inorganic Materials (NIRIM), 1-1 Namiki, Tsukuba, Ibaraki 305, JAPAN;
telefax +81 298 52 7449; e-mail muromac@nirim.go.jp. Key words: high-
pressure synthesis, (GezCu1-z)Sr2Can-1-xYxCunO2n+3, magnetic
susceptibility, electric resistivity, HRTEM.
Andreas Mielke, "Similarity Renormalization of the Electron-Phonon
Coupling." Preprint #HD-TVP-96-9. Institut fuer Theoretische Physik,
Ruprecht-Karls-Universitaet, Philosophenweg 19, D-69120 Heidelberg,
GERMANY; telephone +49 6221 549-428 or -431; telefax +49 6221 549-331;
e-mail mielke@tphys.uni-heidelberg.de; preprint also available at cond-
mat@xxx.lanl.gov (#9609065). Key words: electron-phonon coupling,
effective interactions, superconductivity.
F. Mrovka, M. Wurlitzer, P. Esquinazi, E. H. Brandt, M. Lorenz, and K.
Zimmer, "Non-Linear ac Susceptibility of High Temperature
Superconducting Rings." To be published in Appl. Phys. Lett. Contact
P. Esquinazi, Department of Superconductivity and Magnetism,
Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig, GERMANY.
74.60.Ge; 74.72.Bk; 74.76.Bz.
Paula P. Newcomer, Michael P. Siegal, Eugene L. Venturini, Bruno
Morosin, and Donald L. Overmyer, "Microstructural Changes in
TlBa2CaCu2O7-d Thin Films After Reducing Anneals Which Enhance Critical
Current Density." Presented at the Appl. Supercond. Conf. (ASC'96),
Pittsburgh, PA, Aug. 25-30, 1996; to be published in IEEE Trans. Applied
Supercond. Sandia National Laboratories, P.O. Box 5800, Org. 1153,
Albuquerque, NM 87185-1421.
R. M. Noack, N. Bulut, D. J. Scalapino, and M. G. Zacher, "Enhanced
d_[x^2-y^2] Pairing Correlations in the Two-Leg Hubbard Ladder."
Institut fuer Theoretische Physik, Universitaet Wuerzburg, Am Hubland,
D-97074 Wuerzburg, GERMANY; N. Bulut's telephone at University of
California in Santa Barbara, CA (805) 893-2246; telefax (805) 893-8838;
e-mail nejat@spock.physics.ucsb.edu; preprint also available at cond-
mat@xxx.lanl.gov (#9612165).
Henrik Nordborg and Gianni Blatter, "Vortices and 2D Bosons: A Path-
Integral Monte Carlo Study." Preprint #ETH-TH/96/52; submitted to Phys.
Rev. Lett. Institut fuer Theoretische Physik, ETH-Hoenggerberg, CH-8093
Zurich, SWITZERLAND; telephone +41 1 633-2573 or -2570 or -2571; telefax
+41 1 633-1115; e-mail henrik@itp.phys.ethz.ch; preprint also available
at cond-mat@xxx.lanl.gov (#9612025). 74.20.De; 74.60.Ec; 05.30.Jp.
Akihiro Odagawa, Masahiro Sakai, Hideaki Adachi, Kentaro Setsune,
Tetsuji Hirao, and Kunio Yoshida, "Observation of Intrinsic Josephson
Junction Properties on (Bi,Pb)SrCaCuO Thin Films." To be published in
Jpn. J. Appl. Phys. Central Research Laboratories, Matsushita Electric
Industrial Co., Ltd., 3-4 Hikaridai, Seika, Soraku, Kyoto 619-02, JAPAN;
telephone +81 774 98 2514; telefax +81 774 98 2585. Key words: high-Tc
superconductor, intrinsic Josephson junction, (Bi,Pb)2Sr2Ca2Cu3Ox, thin
film, order parameter of superconductivity.
G. A. Ovsyannikov, "Josephson Junctions in HTSC Films and Their Possible
Applications at MW Frequencies." Presented at the NATO Advanced
Research Workshop on Microwave Physics and Techniques, Sozopol,
Bulgaria, Sept. 30-Oct. 5, 1996. Institute of Radio Engineering and
Electronics, Russian Academy of Sciences, 103907 Moscow, RUSSIA.
Gennady A. Ovsyannikov, Iosif M. Kotelyanski, Peter B. Mozhaev,
Alexander D. Mashtakov, Karen Y. Constantinian, Zdravko G. Ivanov, and
Donats Erts, "New Approach in High-Tc Step-Edge Junctions: Non-Etching
Technique." Institute of Radio Engineering and Electronics, Russian
Academy of Sciences, 103907 Moscow, RUSSIA.
M. Paranthaman, A. Goyal, F. A. List, E. D. Specht, D. F. Lee, P. M.
Martin, Qing He, D. K. Christen, D. P. Norton, J. D. Budai, and D. M.
Kroeger, "Growth of Biaxially Textured Buffer Layers on Rolled-Ni
Substrates by Electron Beam Evaporation." To be published in Physica C.
Chemical and Analytical Sciences Division, Oak Ridge National
Laboratory, Building 4500 South, MS 6100, Oak Ridge, TN 37831-6100;
telephone (423) 574-5045; telefax (423) 574-4939; e-mail p11@ornl.gov.
P. V. Patanjali and V. Seshu Bai, "rf Surface Impedance in BSCCO and
Melt Textured YBCO Superconductors." To be published in IEEE Trans.
Appl. Supercond. School of Physics, University of Hyderabad, Hyderabad
500 046, INDIA; e-mail vsbsp@uohyd.ernet.in.
P. V. Patanjali, V. Seshu Bai, R. M. Kadam, and M. D. Sastry,
"Observation of Paramagnetic Meissner Effect in GdBCO Powder -- a
Microwave Absorption Study." Presented at the Int. Symp. on Adv. in
Supercond.: New Materials, Critical Currents, and Devices, Tata Inst.
of Fundamental Research, Mumbai, India, Sept. 17-20, 1996. School of
Physics, University of Hyderabad, Hyderabad 500 046, INDIA; e-mail
vsbsp@uohyd.ernet.in.
G. B. Peacock, I. Gameson, P. P. Edwards, M. Khaliq, G. Yang, T. C.
Shields, and J. S. Abell, "Fabrication of High-Temperature
Superconducting HgBa2CuO4+d Within Silver-Sheathed Tapes." To be
published in Physica C (in press). Contact P. P. Edwards, School of
Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT,
UNITED KINGDOM; telefax +44 121 414 4403.
T. B. Peterson, U. Welp, G. W. Crabtree, N. Vasanthamohan, J. P. Singh,
M. T. Lanagan, V. K. Vlasko-Vlasov, and V. I. Nikitenko, "Direct Imaging
of Current Sharing in (BiPb)2Sr2Ca2Cu3Ox Composite Conductors."
Submitted to Appl. Phys. Lett. Contact Janice Coble, Argonne National
Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708)
252-9595; e-mail janice_coble@qmgate.anl.gov.
Stephen W. Pierson, "The Current-Temperature Phase Diagram of Layered
Superconductors." Department of Physics, Worcester Polytechnic
Institute (WPI), Worcester, MA 01609-2280; e-mail pierson@wpi.edu; Web
site www.wpi.edu/~pierson/pubs.html; preprint also available at cond-
mat@xxx.lanl.gov (#9612221). 74.60.Jg; 74.25.Dw; 74.72.-h; 64.60.Ak.
Thomas Rentschler, "Doping of the Quadruple Perovskites of Type
Nd2Ba2Cu2Ti2-xMxO11, M=Mn,Fe,Co,Al and NdBa3Cu2Ti1+xNb1-xO11." To be
published in Physica C. University of Hamburg, Institute of Inorganic
and Applied Chemistry, Martin-Luther-King-Platz 6, D-20146 Hamburg,
GERMANY. Key words: perovskite, superconductivity, superstructure,
Rietveld method.
K. V. Samokhin, "Larkin-Ovchinnikov-Fulde-Ferrell State in d-Wave
Superconductors." To be published in Physica C (in press). Institut
fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, D-
50937 Koeln, GERMANY; telefax +49 221 470 5159; e-mail samokhin@thp.uni-
koeln.de. Key words: d-wave superconductor, modulated structures,
specific heat at low T. 74.20.Hi; 74.80.-g; 74.72.-h.
R. Sasik, L. N. Bulaevskii, A. R. Bishop, and M. P. Maley, "Vortices and
Plasmons in Inductive Periodic Josephson Junction Arrays." Manuscript
#LA-UR-96-4674. Los Alamos National Laboratory, Los Alamos, NM 87545.
D. J. Scalapino, "Pairing Mechanism in Two Hubbard Models that Show
d_[x^2-y^2] Pairing." Department of Physics, University of California,
Santa Barbara, CA 93106-9530; preprint also available at cond-
mat@xxx.lanl.gov (#9606218).
D. J. Scalapino, "Pairing Mechanism in the Two-Dimensional Hubbard
Model." Department of Physics, University of California, Santa Barbara,
CA 93106-9530; preprint also available at cond-mat@xxx.lanl.gov
(#9606217).
F. Schmidl, L. Doerrer, S. Wunderlich, F. Machalett, U. Huebner, H.
Schmidt, S. Linzen, H. Schneidewind, N. V. Freyhold, and P. Seidel,
"Superconducting Properties of Ion Beam Modified YBCO Microbridges."
Presented at the Proc. of the Weak Supercond. Symp., Smolenice, Slovak
Republic, Aug. 4-7, 1996; submitted to J. Low. Temp. Phys. Institut
fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena,
Lessingstrasse 8, D-07743, Jena, GERMANY; P. Seidel's telephone +49
3641-635685 or -635681; telefax +49 3641-635681; e-mail seidel@ifk.uni-
jena.de. 74.50.+r.
H. Schneidewind, S. Wunderlich, F. Schmidl, L. Doerrer, and P. Seidel,
"Application of Ion Beam Etching to Investigate the Electrical Behavior
of Josephson Junctions." Presented at the NATO Adv. Research Workshop
on Physics and Mater. Sci. of High Temp. Supercond. IV, Strbske Pleso,
Slovak Republic, July 21-27, 1996. Institute fuer Festkoerperphysik,
Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena,
GERMANY; P. Seidel's telephone +49 3641-635685; or -635681; telefax +49
3641-635681; e-mail seidel@ifk.uni-jena.de.
Shara S. Shoup, Mariappan Paranthaman, David B. Beach, E. D. Specht, and
Robert K. Williams, "Sol-Gel Synthesis of LaAIO3: Epitaxial Growth of
LaAIO3 Thin Films on SrTiO3 (100)." To be published in J. Mater. Res.
(in press). Chemical and Analytical Sciences Division, Oak Ridge
National Laboratory, Building 4500 South, MS 6100, Oak Ridge, TN 37831-
6100; Mariappan Paranthaman's telephone (423) 574-5045; telefax (423)
574-4939; e-mail p11@ornl.gov.
Michael P. Siegal, Donald L. Overmyer, Eugene L. Venturini, Paula P.
Newcomer, Roberto Dunn, Frank Dominguez, Richard R. Padilla, and Sara S.
Sokolowski, "Importance of Thermodynamics and Kinetics in the Growth of
Thin Film TIBaCaCuO Superconductors." Presented at the Appl. Supercond.
Conf. (ASC'96), Pittsburgh, PA, Aug. 25-30, 1996; to be published in
IEEE Trans Supercond. Sandia National Laboratories, Albuquerque, NM
87185-1421.
Steven H. Simon and Patrick A. Lee, "Scaling of the Quasiparticle
Spectrum for d-Wave Superconductors." Submitted to Phys. Rev. Lett.
Department of Physics, Massachusetts Institute of Technology, Room 12-
105, Cambridge, MA 02139; e-mail simon@cmt10.mit.edu; preprint also
available at cond-mat@xxx.lanl.gov (#9611133). 74.25.Fy; 74.72.-h;
74.25.Jb.
H. K. Singh, A. K. Saxena, and O. N. Srivastava, "Effect of Ag Doping on
the Transition Temperature and Critical Current Density of Hg1-
xTlxBa2Ca2Cu3O8+d Films Fabricated Through Spray Pyrolysis." To be
published in Physica C (in press). Contact O. N. Srivastava, Department
of Physics, Banaras Hindu University, Varanasi 221 005, INDIA; telefax
+91 542 31 4468. Key words: superconductors, transition temperature,
critical current.
V. V. Srinivasu, Pratap Raychaudhuri, C. P. D'Souza, R. Pinto, and R.
Vijayaraghavan, "Microwave Surface Resistance in Lu1-xPrxBa2Cu3O7-d Thin
Films." To be published in the Proc. of the Int. Symp. on Advances in
Superconduc.: New Materials, Critical Currents and Devices, (ASMCCD
'96), Mumbai, India, Sept. 17-20, 1996. Tata Institute of Fundamental
Research, Homi Bhabha Road, Colaba, Mumbai 400 005, INDIA; telefax +91
22 215 2110; e-mail vvs@tifrvax.tifr.res.in.
H. Teshima, M. Tanaka, K. Miyamoto, K. Nohguchi, and K. Hinata, "Effect
of Eddy Current Dampers on the Vibrational Properties in Superconducting
Levitation Using Melt-Processed YBaCuO Bulk Superconductors." To be
published in Physica C (in press). Advanced Technology Research
Laboratories, Nippon Steel Corporation, 1618 Ida, Nakahara-ku, Kawasaki
211, JAPAN; telefax +81 44 752 5759; e-mail hteshima@lab1.nsc.co.jp.
Key words: superconducting levitation, YBaCuO, melt-processed bulk
material, vibrational properties, eddy-current damper.
P.H.E. Tiesinga, T. J. Hagenaars, J. E. van Himbergen, and Jorge V.
Jose, "1/omega Flux Noise and Dynamical Critical Properties of Two-
Dimensional XY-Models." Instituut voor Theoretische Fysica,
Princetonplein 5, Postbus 80006, 3508 TA Utrecht, THE NETHERLANDS; Jorge
V. Jose's e-mail at Northeastern University, Boston, MA,
jose@citlalli7.physics.neu.edu; preprint also available at cond-
mat@xxx.lanl.gov (#9611208). 74.20.-z; 64.60.Fr; 74.50.+r; 74.40.+k.
M. Ullrich, A. Leenders, and H. C. Freyhardt, "Levitation Forces and
Mechanical Properties of VGF Melt-Textured YBCO." Presented at the
Appl. Supercond. Conf., Pittsburgh, PA, Aug. 25-30, 1996; to be
published in IEEE Trans. Appl. Supercond. Zentrum fuer
Funktionswerkstoffe GmbH Goettingen, Windausweg 2, D-37073 Goettingen,
GERMANY; telefax +49 551 5071750; e-mail ullrich@umpsun1.gwdg.de.
Eugene L. Venturini, Paula P. Newcomer, Michael P. Siegal, and Donald L.
Overmyer, "Enhanced Vortex Pinning in Annealed TlBa2CaCu2Ox Thin Films."
Presented at the Appl. Supercond. Conf. (ASC'96), Pittsburgh, PA, Aug.
25-30, 1996.; to be published in IEEE Trans. Appl. Supercond. Sandia
National Laboratories, Albuquerque, NM 87185-1421.
R. K. Wang, X. H. Wang, R. Bhasale, H. K. Liu, and S. X. Dou, "Study of
Microstructures of Ag-Sheathed BPSSCO Multifilamentary Tapes in Various
Stages of Processing." General Institute of Non-Ferrous Metals, Beijing
100088, PEOPLE'S REPUBLIC OF CHINA.
R. Weidl, S. Brabetz, F. Schmidl, F. Klemm, S. Wunderlich, and P.
Seidel, "Heart Monitoring with High-Tc dc-SQUID Gradiometers in
Unshielded Environment." Submitted to Supercond. Sci. & Technol.
Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet,
Lessingstrasse 8, D-07743 Jena, GERMANY; P. Seidel's telephone +49 3641-
635685; or -635681; telefax +49 3641-635681; e-mail seidel@ifk.uni-
jena.de. 85.25.Dq.
B. O. Wells, Y. S. Lee, M. A. Kastner, R. J. Christianson, F. C. Chou,
R. J. Birgeneau, K. Yamada, Y. Endoh, and G. Shirane, "Structural Phase
Transitions and Incommensurate Spin Fluctuations in the La2CuO4+y
System." To be published in NATO ASI Series. Department of Physics and
Center for Materials Science and Engineering, Massachusetts Institute of
Technology, Cambridge, MA 02139.
W. Wong-Ng, E. J. Gonzalez, G. J. Piermarini, Ch. Wolters, J. Schwartz,
and M. R. Gallas, "X-ray Diffraction Study of High Tc and Related Phases
at High Pressures." Submitted to Adv. X-ray Anal. A215 MATLS, National
Institute of Standards & Technology, Gaithersburg, MD 20899-0001;
telephone (301) 975-5791; telefax (301) 990-8729; e-mail
wongng@tiber.nist.gov.
W. C. Wu and J. P. Carbotte, "c-axis Raman Spectra of a Normal Plane-
Chain Bilayer Cuprate and the Pseudogap." Submitted to Phys. Rev. B.
Department of Physics and Astronomy, McMaster University Hamilton,
Ontario, CANADA L8S 4M1. 74.80.Dm; 78.30.-j; 74.25.Jb; 74.72.-h.
X.-J. Wu, A. Tokiwa-Yamamoto, T. Tatsuki, S. Adachi, and K. Tanabe,
"Structure Evolution in Superconducting (Hg0.7,Tl0.3)2Ba2(Cax,Y1-
x)Cu2O8-2d." To be published in Physica C (in press).
Superconductivity Research Laboratory, International Superconductivity
Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135,
JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714
or -5717.
Yuji Yamaguchi, Hirokazu Tomono, Fumitoshi Iga, and Yoshikazu Nishihara,
"Dimensionality of Vortex State Magnetization in Tilted-Field to c-Axis
of Bi2Sr2CaCu2Oy." To be published in Physica C (in press).
Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305, JAPAN;
telefax +81 298 58 5387. Key words: tilted field, magnetization,
vortex transition, vortex dimensionality, Bi2Sr2CaCu2O8.
H. Yamasaki, Y. Nakagawa, Y. Mawatari, and B. Cao, "Preparation and
Magnetic Properties of Re-Doped HgBa2Ca2Cu3O8+d Superconductors." To be
published in Physica C (in press). Electrotechnical Laboratory, 1-1-4
Umezono, Tsukuba, Ibaraki 305, JAPAN. Key words: HgBaCaCuO, rhenium
doping, magnetization, surface barrier.
S. H. Yoo, K. W. Wong, and Y. Xin, "Thick Film of HgBa2Ca2Cu3O8+d via
the Sol-Gel Technique." To be published in Physica C (in press).
Department of Physics and Astronomy, University of Kansas, Lawrence, KS
66045; e-mail kimyoo@falcon.cc.ukan.edu. Key words: high-temperature
superconductivity, thick film HgBa2Ca2Cu3O8+d, synthesis. 74.76.Bz;
81.15.-z.
Z. Q. Yu and W. J. Yeh, "Scaling Behavior and 3D-2D Dimensional
Crossover in Ceramic Tl2Ba2Ca2Cu3O10-d High-Tc Superconductors." To be
published in Physica C (in press). Contact W. J. Yeh, Department of
Physics, University of Idaho, Moscow, ID 83844. Key words: glassy
state, phase diagram, dimensional crossover.
X. F. Zhang, V. R. Todt, and D. J. Miller, "From Meandering to Straight
Grain Boundaries: Improving the Structures of Artificially-Induced
Grain Boundaries in Superconducting YBa2Cu3Oy Bicrystals." Submitted to
Phys. Rev. B. Contact Janice Coble, Argonne National Laboratory, 9700
South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail
janice_coble@qmgate.anl.gov. Key words: superconducting grain
boundary, microstructure. 61.72.Mn; 74.72.Bk.
Kh. A. Ziq and M. M. Abdelhadi, "Non-Ohmic I-V Behavior in YBa2Cu3O7-
d/Ag2O High Tc Superconductors Composite." Presented at the Int. Conf.
on Physics and Chemistry of Molecular and Oxide Supercond. (MOS'96),
Karlsruhe, Germany, Aug. 2-6, 1996; to be published in J. Low Temp.
Phys. Department of Physics, King Fahd University of Petroleum and
Minerals, Dhahran 31261, SAUDI ARABIA. 74.60.Ge.
COMING EVENTS
(An * indicates a previously listed event.)
*April 3 - 4, 1997: Workshop on ac Losses, San Francisco Marriott, San
Francisco, CA. Sponsored by the Electric Power Research Institute
(EPRI). Two-day workshop will cover theoretical and experimental
research on power-line-frequency (50-60 Hz) ac losses in high-
temperature superconductors, and the influence such losses have on the
design of HTS devices for electric power applications. Program will
consist of talks, posters, and workshop discussions. No registration
fee, but attendance will be limited to 50 participants. Workshop will
follow Symposium R: Materials Issues Related to Development of Textured
High-Temperature Superconducting Conductors at the 1997 MRS Spring
Meeting, being held April 1-2, 1997, at the same location. Applications
via e-mail consisting of name, institution, address, phone and fax
numbers, e-mail address, and an abstract, will be used to select oral
and poster presentations. Application deadline, February 1, 1997. For
further information, contact the workshop organizers, preferably by e-
mail: John R. Clem, A517 Physics, Iowa State University, Ames, IA
50011, telephone (515) 294-4223, telefax (515) 294-0689, e-mail
clem@ameslab.gov; or Masaki Suenaga, Brookhaven National Laboratory,
Bldg. 480, Upton, NY 11973, telephone (516) 282-3518, telefax (516) 282-
4071, e-mail mas@sun2.bnl.gov. For separate information about the 1997
MRS Spring Meeting and accommodations, contact the Materials Research
Society, 9800 McKnight Road, Pittsburgh, PA 15237-6006, telephone (412)
367-3003, telefax (412) 367-4373, e-mail info@mrs.org.
May 4 - 9, 1997: Fourth International Symposium on Quantum Confinement:
Nanoscale Materials, Devices, and Systems, 191st Electrochemical Society
Meeting, Montreal, Canada. Will address recent developments in the area
of nanoscale semiconducting, metallic, and superconducting structures
with emphasis on ultrasmall clusters and their potential for device
applications. Papers will cover fundamental aspects of science and
engineering, as well as related technology and applications. Areas of
particular interest include clusters and other nanostructures, novel
fabrication techniques for nanostructures, electron transport in
isolated and coupled quantum wires and dots, cooperative phenomena in
nanoclusters, optical properties of quantum wires and dots, new device
ideas, mesoscopic superconductors, and quantum architectures and
circuits. For information contact J. P. Leburton, Beckman Institute,
405 N. Mathews Avenue, University of Illinois, Urbana, Illinois, IL
61801; telephone (217) 333-6813; telefax (219) 244-4333; e-mail
leburton@ceg.uiuc.edu.
*May 25 - 28, 1997: International Workshop on Tl and Hg Based
Superconducting Materials, University Centre, University of Cambridge,
United Kingdom. Objective is to provide a comprehensive overview of
research and development activities in these materials. Main topics
include: processing, physical properties, critical currents and
microstructure of single crystals, thick and thin films, and wires and
tapes. About twenty invited lectures, and oral and poster papers.
Proceedings to be published. Abstract deadline, February 28, 1997;
preregistration deadline, March 31, 1997. For further information,
contact Shiming Wu, IRC in Superconductivity, University of Cambridge,
Cambridge CB3 0HE, United Kingdom; telefax +44 1223 33 7074; e-mail
sw204@cus.cam.ac.uk; Web site
http://www.sucon.cam.ac.uk/workshops/iwtlhg.html.
*June 8 - 20, 1997: NATO Advanced Study Institute on Applications of
Superconductivity, Hotel Alexandra, Loen, Norway. The scientific bases,
technological issues, and market potential of all current and emerging
applications will be considered. These will include the fabrication of
cables and magnets; power conditioning and transmission; energy storage;
microwave electronics; SQUID magnetometry in biomagnetism, geophysics,
and nondestructive evaluation; and analog and digital circuitry.
Cryogenic and materials issues will be covered. Application deadline,
February 18, 1997. For information on financial assistance and/or
application, contact Harold Weinstock, AFOSR/NE, Bolling AFB, DC 20332-
8080; telefax (202) 767-4986; e-mail harold.weinstock@afosr.af.mil.
(The preferred mode of communication is e-mail.)
June 25 - 28, 1997: TMS 39th Electronic Materials Conference (EMC),
Colorado State University, Fort Collins, CO. Provides forum for topics
of current interest and significance in the area of preparation and
characterization of electronic materials. Will include exhibit of
electronic materials technology and services. Major thrust areas
include: growth characterization and processing of wide-bandgap
materials; quantum effect materials and devices; fabrication and
characterization of materials at the nanoscale level; in-situ real-time
monitoring and characterization; epitaxial growth; and defects,
characterization, and reliability. Papers are solicited. Abstract
deadline, February 7, 1997. For information, contact Thomas Kuech,
Program Chair, Department of Chemical Engineering, University of
Wisconsin, 1415 Engineering Drive, Madison, WI 53706; telephone (608)
263-2922; telefax (608) 265-3782; e-mail kuech@engr.wisc.edu.
Nov. 16 - 21, 1997: ASME International Mechanical Engineering Congress
& Exposition: Technical Session on Low-Temperature Electronics, Dallas,
TX. A session jointly organized by the Heat Transfer Division, the
Superconductivity Technical Committee, and the Electronic Packaging
Division will focus on thermal and mechanical aspects of superconducting
and semiconducting electronics. Potential topics include thermal
management, thermal stresses, microscale effects, heat transfer at
cryogenic temperatures, and thermal and mechanical properties at low
temperatures. Abstract deadline, January 17, 1997. Contact Patrick E.
Phelan, Arizona State University, Department of Mechanical & Aerospace
Engineering, PO Box 876106, Tempe, AZ 85287-6106; telephone (602) 965-
1625; telefax (602) 965-1384; e-mail phelan@asu.edu.
FYI
(High-Tc Update takes no responsibility for want ads listed in this
section.)
Positions open: The National High Magnetic Field Laboratory (NHMFL) at
Florida State University has two postdoctoral openings. The first
involves research and fabrication of HTS magnets with emphasis on thin
ceramic coatings. Project will include all aspects of HTS coil
development, and microstructural and electrical characterization of
coatings. Ph.D. in ceramic engineering, materials science, or related
fields with appropriate experience is required. The second position
involves research and development of BSCCO HTS conductors for high-
magnetic-field insert coils. Will involve all aspects of PIT conductor
processing, including mechanical deformation, heat treatment,
microscopy, and electromagnetic characterization. Ph.D. in materials
science, mechanical engineering, or related field, with appropriate
experience, is required. Applicants should send resume with names of
references to Yusuf Hascicek (for first opening), National High Magnetic
Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32306-4005;
phone (904) 644-0859; fax (904) 644-0867; e-mail
yusuf@magnet.fsu.edu;
or Justin Schwartz (for second opening), Associate Professor of
Mechanical Engineering, Room A243, National High Magnetic Field
Laboratory & FAMU-FSU College of Engineering, 1800 E. Paul Dirac Drive,
Tallahassee, FL 32310, phone (904) 644-0874, fax (904) 644-0867, e-mail
schwartz@magnet.fsu.edu.
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,
Project Director/Editor: Sreeparna Mitra
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.
Science Editor: John R. Clem
High-Tc Update, Vol. 11, #2, January 15, 1997.