2-GAP STRUCTURE IN YB(Y)BA2CU3O7-X SINGLE-CRYSTALS

Authors
AMINOV BA HEIN MA MULLER G PIEL H WEHLER D PONOMAREV YG ROSNER K WINZER K
Citation
Ba. Aminov et al., 2-GAP STRUCTURE IN YB(Y)BA2CU3O7-X SINGLE-CRYSTALS, Journal of superconductivity, 7(2), 1994, pp. 361-365
Citations number
16
Categorie Soggetti
Physics, Applied","Physics, Condensed Matter
Journal title
Journal of superconductivity → ACNP
ISSN journal
08961107
Volume
7
Issue
2
Year of publication
1994
Pages
361 - 365
Database
ISI
SICI code
0896-1107(1994)7:2<361:2SIYS>2.0.ZU;2-U
Abstract
Tunneling effects in YbBa2Cu3O7-x (YbBCO) and YbBa2Cu3O7-x (YBCO) sing le crystals have been investigated using an improved technique of brea k junction preparation. A two-gap structure with BCS-like density of s tates has been observed. The value of the ''large'' gap is in the rang e of 24-28 meV for YBCO (T(c) = 85-90 K) and 29-30 meV for YbBCO (T(c) = 87-90 K). A variation of the value of the ''small'' gap between 0.5 and 11 meV has been detected, even for the same crystal. As a possibl e explanation, two-band superconductivity, surface properties or stron g gap anisotropy will be discussed.