SOLID-STATE PROCESSING AND PHASE DEVELOPMENT OF BULK (MGO)(W) BPSCCO HIGH-TEMPERATURE SUPERCONDUCTING COMPOSITE/

The inherently weak mechanical properties associated with monolithic h igh-temperature superconductors (HTS) can be improved by introducing p roperly selected strong ceramic whiskers into the HTS materials. In th is research, processing and superconducting properties of monolithic P b-doped Bi-2223 (BPSCCO) and MgO whisker-reinforced BPSCCO HTS composi te materials have been systematically studied. A solid-state processin g method is successfully developed to fabricate the (MgO)(w)/BPSCCO co mposite. The HTS composite contains a dense and highly pure BPSCCO mat rix phase with a preferred grain orientation, which is reinforced by M gO whiskers randomly oriented in the plane perpendicular to the hot-pr essing direction. The HTS composite material is shown to exhibit excel lent superconducting properties. For example, a transport J(c) measure d at 77 K in a zero field has been obtained to exceed 5000 A/cm(2) in a (MgO)(w)/BPSCCO composite with 10% MgO whiskers by volume. Relations hips among solid-state processing variables, HTS phase development, an d superconducting properties of the monolithic BPSCCO and the HTS comp osite are established in the paper.