Pinning by twin boundaries and peak effect in YBaCuO high-T c superconductors |
| |
Authors: | I. F. Voloshin A. V. Kalinov L. M. Fisher K. I. Kugel’ A. L. Rakhmanov |
| |
Affiliation: | (1) State Research Center “All-Russian Electrical Engineering Institute”, 111250 Moscow, Russia;(2) Scientific Center for Applied Problems in Electrodynamics, Russian Academy of Sciences, 127412 Moscow, Russia |
| |
Abstract: | Measurements of the imaginary part of the ac magnetic susceptibility of single crystals and melt-textured samples of YBa2Cu3Ox (YBCO) at T=77 K in a magnetic field ranging between 1 and 20 kOe are reported. If the dc magnetic field H dc is rotated in the ab plane of the sample, the magnetic susceptibility and critical current density j c have peaks corresponding to the magnetic field aligned with twin boundaries. Peaks in the curve of j c versus magnetic field are observed at angles corresponding to these peaks, where AH dc in a wide range of magnetic fields. The results have been interpreted in terms of the theory describing twin boundaries as a system of quasi-planar pinning sites. The pinning is strong if the elastic displacements of flux lines are of the order of the vortex lattice constant d f. These displacements decrease with the magnetic field because of the decrease in d f, and the contribution of the elastic energy to the Gibbs potential is reduced accordingly, which is the cause of the peak effect. Zh. éksp. Teor. Fiz. 111, 2158–2174 (June 1997) |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|