SURFACE-RESISTANCE OF GRAIN-ALIGNED YBA2CU3OX BULK - EVIDENCE FOR 2 KINDS OF WEAK LINK

被引：16

作者：

WOSIK, J ^{[1
]}

XIE, LM ^{[1
]}

CHAU, R ^{[1
]}

SAMAAN, A ^{[1
]}

WOLFE, JC ^{[1
]}

SELVAMANICKAM, V ^{[1
]}

SALAMA, K ^{[1
]}

机构：

[1] UNIV HOUSTON,DEPT ELECT ENGN,HOUSTON,TX 77204

来源：

PHYSICAL REVIEW B | 1993年 / 47卷 / 14期

关键词：

D O I：

10.1103/PhysRevB.47.8968

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have measured the magnetic-field and temperature dependence of the surface resistance R(s) of grain-aligned YBa2Cu3Ox. Experiments were conducted on ab-plane- and ac-plane-oriented samples, with the dc magnetic field parallel and perpendicular to the sample surface. We explain the nonlinear behavior of R(s) at low field using a model with an array of Josephson weak links and the linear dependence on magnetic field at high field using an oscillatory-vortex-motion-loss model. The model allows a quantitative fit to the experimental data using the lower critical field of the grain, the entry field H(c1J) of weak links, the junction decoupling parameter H(d), and the vortex viscosity as fitting parameters. Two different sets of parameters H(d) and H(c1J) were used to fit the data, suggesting that in grain-aligned YBa2Cu3Ox bulk material at least two kinds of weak link are responsible for low-field losses. An estimation of the Josephson-junction area was obtained from field-modulated microwave absorption. In addition, thermal-excitation and radiation-activation mechanisms for rf losses are compared.

引用

页码：8968 / 8977

页数：10

共 37 条

[1] MICROSTRUCTURE WITHIN DOMAINS OF MELT-PROCESSED YBA2CU3O7-X SUPERCONDUCTORS [J].