Glassy exponent of melt textured YBCO extracted from magnetic hysteresis loops with various field sweep rates

An analogy between the vortex and spin glass is examined by the determination of the melting temperature T-m of the vortex glass by ac susceptibility for a melt-textured growth YBa2Cu3O7 bulk sample. The melting line T-m(B) is determined and obeys a power law: B proportional to (1-t)(beta) with beta=1.57, where t=T-m/T-c is the reduced temperature.