THE RELAXATION OF THE MONODOMAIN TMBA2CU3OX SINGLE-CRYSTAL MAGNETIZATION IN THE SUPERCONDUCTING STATE

Measurements of the remanent magnetization relaxation RM(t) in the monodomain TmBa2Cu3Ox single crystal are reported. The relaxation rate r(T) = dRM(T, t)/d(ln t) has a sharp maximum at temperature T = Tmax. The Tmax value is about 15 K for H = 2.8 kOe and it strongly depends on the magnitude of the applied magnetic field being shifted to higher temperatures as H is decreased. The normalized rate r(T)/RM0 in contrast to the r(T) behavior, is almost isotropic irrespective of the H direction. The r(T) maximum is qualitatively reproduced by the calculation taking into account the thermal activated flux creep and Abrikosov vortices distribution according to the Bean model. © 1990.