VORTEX FLUCTUATION EFFECT IN 3-DIMENSIONAL SUPERCONDUCTORS

This paper reports the experimental results on reversible magnetizatio n at high fields for grain aligned HgBa2Ca0.86Sr0.14Cu2O6-delta and YB a2Cu3O7-delta which are known to be anisotropic three dimensional supe rconductors. A crossover of magnetization curves M(T) for various magn etic fields are clearly observed near T-c, which indicates the vortex fluctuation effect. In these SD-superconductors, the fluctuation of vo rtices was quantitatively interpreted for the first time from extensio n of the vortex fluctuation model. These results are compared with tho se of PD-superconductors.