3 research outputs found
Role of Interfaces in the Proximity Effect in Anisotropic Superconductors
We report measurements of the critical temperature of YBCO-Co doped YBCO
Superconductor-Normal bilayer films. Depending on the morphology of the S-N
interface, the coupling between S and N layers can be turned on to depress the
critical temperature of S by tens of degrees, or turned down so the layers
appear almost totally decoupled. This novel effect can be explained by the
mechanism of quasiparticle transmission into an anisotropic superconductor.Comment: 13 pages, 3 figure
Magnetic field induced polarization effects in intrinsically granular superconductors
Based on the previously suggested model of nanoscale dislocations induced
Josephson junctions and their arrays, we study the magnetic field induced
electric polarization effects in intrinsically granular superconductors. In
addition to a new phenomenon of chemomagnetoelectricity, the model predicts
also a few other interesting effects, including charge analogues of Meissner
paramagnetism (at low fields) and "fishtail" anomaly (at high fields). The
conditions under which these effects can be experimentally measured in
non-stoichiometric high-T_c superconductors are discussed.Comment: 10 pages (REVTEX), 5 EPS figures; revised version accepted for
publication in JET
Chemomagnetism, magnetoconcentration effect and "fishtail" anomaly in chemically-induced granular superconductors
Within a 2D model of Josephson junction arrays (created by 2D network of twin
boundary dislocations with strain fields acting as insulating barrier between
hole-rich domains in underdoped crystals), a few novel effects expected to
occur in intrinsically granular material are predicted including: (i) Josephson
chemomagnetism (chemically induced magnetic moment in zero applied magnetic
field) and its influence on a low-field magnetization (chemically induced
paramagnetic Meissner effect), and (ii) magnetoconcentration effect (creation
of oxygen vacancies in applied magnetic field) and its influence on a
high-field magnetization (chemically induced analog of "fishtail" anomaly). The
conditions under which these effects can be experimentally measured in
non-stoichiometric high-T_c superconductors are discussed.Comment: 5 LaTeX pages (jetpl.sty included), 3 EPS figures. To be published in
JETP Letters (January 2003