Flux Creep in Sintered Superconducting Y-Ba-Cu-O

Abstract

The flux creep rate in sintered superconducting Y-Ba-Cu-O was measured at 77 K and in fields of up to 0.1 T. The pinning potential mainly caused by flux pinning inside grains was 0.25 eV at B=50 mT and decreased monotonically with increasing magnetic field. The obtained results can be explained by the theoretical model with observed intragrain current density. This theoretical model suggests that the flux creep at high fields is notable even if a superconducting wire with the critical current density of 2×10¹⁰ A/m² at B=5 T is realized.