Full-penetration temperature and magnetic relaxation in a single crystal of Bi2Sr2CaCu2Ox.

We have developed the concept of a characteristic temperature {ital T}{sup *} at which the flux first fully penetrates the sample. Based on this concept, we have interpreted the effects of the temperature on the magnetic relaxation that have been measured in a single crystal of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub {ital x}} in a broad range of temperature (5--35 K) and applied magnetic field (0.1--4 kG). The magnetic relaxation exhibits a clear peak in the {ital dM}/{ital d} ln{ital t}-versus-temperature plot, and the peak position is highly affected by the applied field. We have also interpreted the peak shift of {ital dM}/{ital d} ln{ital t} with different fields in terms of the flux-creep and the critical-state models.