Flux pinning in zone-melted YBa 2Cu 3O 6+x

Abstract

Low-field hysteresis studies by VSM and high-field Magnetization relaxation studies by SQUID have been performed on a zone-melted YBa 2Cu 3O 6+x sample. Nonlogarithmic magnetic relaxation observed at relatively high temperature and is explained by exponential U(J) relationship, which may result from the local pinning potential U p(x ) rather than collective pinning. At the end, The voltage-current E(J) result from the observed U(J) relationship is discussed.