Author:
Wang J,Ito N,Pyon S,Nishizaki T,Tamegai T
Abstract
Abstract
Enhancement of critical current density (J
c) was observed in YBa2Cu3O7−δ
with splayed columnar defects (CDs). In the case of 90 K-phase YBa2Cu3O7−δ
with splayed CDs, the enhanced J
c drops suddenly at the depinning temperature of vortices from CDs (T
dp), which is interpreted to be caused by the excitation of double kinks traversing neighboring CDs. In addition to the optimal 90 K-phase, where the superconductivity dominates, there is another stable 60 K-phase and other phases with different T
c. This study reports temperature dependence of J
c and the step-like decrease of J
c in YBa2Cu3O7−δ
with CDs and with different T
c. Results show that the T
dp is strongly related to the T
c. However, additional entropic reduction of T
dp may depend on parameters other than T
c.
Subject
General Physics and Astronomy