FLUX-PINNING IN YBA2CU3O7-DELTA THROUGH NANOMETER-SIZED MGO PARTICLES

The magnetization hysteresis loop and magnetic relaxation of YBa2Cu3O7 -delta samples with x=0 and 0.1 were systematically measured over a wi de range of temperature (10-80K) and magnetic field (0-7T). It is foun d that the addition of nanometer-sized MgO particles will enhance the critical current density and the fishtail effect in low- and intermedi ate-temperature region, lower the critical current density in high-tem perature region, and reduce the flux-creep rate.