高温超导体时效与记忆效应实验研究

Large single domain YBaCuO bulks fabricated by the top seeded melt-growth have interest in many potential applications according to their large critical current and mechanical characteristics. This paper describes the experimental results of levitation force of the YBaCuO bulk superconductors preparing by the top seeded melt growth method with different waiting time. It is found that waiting time has large effects on the zero-field-cooled (ZFC) and field-cooled (FC) levitation force, and the levitation force shows aging characteristic at the liquid nitrogen temperature. In Addition, the influences of the negative and / or positive temperature cycle on the levitation force relaxation with time are investigated in the case of zero field cooling (ZFC). Memory effect and its losing are found in the experimental process. Aging and memory properties presented here, similarity to the Spin-glass, which are caused by the microstructures of the superconductors.