Far Infrared, Magnetic and Electronic Studies of High Tc Superconducting Materials.

摘要

Most of the studies of flux motion inside the superconductor are concentrated on the magnetization decay in the zero field cooled condition. A fewer work is on field cooled condition. We investigated the time dependence of the isothermal magnetization in the field cooled condition. We found that when the temperature is lower then 35K the isothermal magnetization decreases with time for every temperature at which the isothermal magnetization measurements were carried out. On contrast, when the temperature is higher then 35K, the isothermal magnetization increases at some temperatures but decreases at the others in the period (15-20 hours) in which we carried out the measurements. We discuss the mechanism of the discovered time-dependence of the isothermal magnetization based upon the thermal activation theory.