HIGH-FIELD MAGNETIZATION OF YBA2(CU,ZN)(3)O-7-DELTA SUPERCONDUCTORS

The high field magnetization of sintered YBa2Cu3-xZnxO7-delta compound s was investigated. By means of Bean's critical state model it is deri ved from magnetization measurements that the slope of critical current density vs. external magnetic field curve becomes less negative and t he flux-pinning force diminishes significantly with increasing zinc co ntent. The magnetic field corresponding to the maximum of the pinning force decreases sharply with increasing zinc content. It is thought th at the destruction of superconductivity in YBa2Cu3O7-delta compounds b y zinc doping is due to the change in electronic structure in the Cu-O -2 planes as well as the reduction in orthorhombic distortion.