Hysteretic magnetization curves of coated conductors calculated using measured field-profile data

The hysteretic magnetization curves of superconducting ReBa ₂Cu₃O₇ (ReBCO, RE: Y, Sm) films were investigated. The YBCO and the SmBCO films were grown on ion-beam-assisted- deposition (IBAD) templates by using the pulsed laser deposition (PLD) method and the coevaporation method, respectively. The field profiles, H(x), near the surfaces of the samples in a magnetic field applied in a direction perpendicular to the surface, H_a, were measured using a scanning Hall probe method. The corresponding sheet current profiles, J(x), in the superconducting thin films were obtained by numerical inversion of the measured field profile data. The negative magnetic moment, M(H_a), per unit length was estimated from J(x). The calculated magnetization hysteresis loops for H _a cycled with amplitude - H_peak were in remarkable agreement with that measured by using a magnetometer. The differences in the hysteresis loops between the two samples are due to the granular characteristics of the samples.