Giant flux creep and irreversibility in an Y-Ba-Cu-O crystal: An alternative to the superconducting-glass model.

摘要: We report strong, anisotropic magnetic relaxation of the field-cooled and zero-field-cooled magnetization along principal axes an Y-Ba-Cu-O single crystal interpret it with a thermally activated flux-creep model. A simple scaling argument shows that high thermal activation causes irreversibilities critical currents to drop below threshold detectability at reduced temperature difference $1\ensuremath{-}t$ proportional ${H}^{\frac{2}{3}}$, power frequently observed in experiment particular our crystal.