Critical current density of a YBa2Cu3O7 film: Comparison between experiment and collective pinning theory |
| |
Authors: | M Ziese P Esquinazi |
| |
Institution: | (1) Physikalisches Institut, University Bayreuth, D-95440 Bayreuth, Germany |
| |
Abstract: | With the vibrating reed technique we have measured the critical current densityJ
c
of a Y 123 200 nm thin film as a function of magnetic field perpendicular to the CuO2 planes (O T<B8 T) and temperature (20KT60 K). At fieldsB<0.1 TJ
c
is magnetic field independent and decreases at higher fields. A comparison with theory indicates that a crossover from a single pinning to a small bundle collective pinning regime may explain the observed behaviour. According to our estimate the main pinning centers are weak point pins due to oxygen vacancies. From the temperature dependence ofJ
c
atB0 we obtain a temperature dependence of the thermodynamical critical fieldB
c
(1–T/T
c
)2 forT20 K which agrees with the anomalous temperature dependence ofB
c2
observed recently in highly anisotropic high temperature superconductors. |
| |
Keywords: | 74 72 -k 74 60 Ge 62 40 +i |
本文献已被 SpringerLink 等数据库收录! |