Microstructure of high Jc NdBa2Cu3Ox/Nd4Ba2Cu2O10 composite superconductor

Single crystalline NdBa2Cu3Ox (Nd123) superconductors with dispersed Nd4Ba2Cu2O10 (Nd422) particles were produced by the floating zone partial melting and solidification (FZPMS) method. The initial composition of the precursor material was Nd1.8Ba2.4Cu3.4Ox with or without 0.1 wt% Pt addition. FZPMS was carried out in a low oxygen partial pressure atmosphere. Microstructure of quenched samples were investigated by optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Furthermore, superconductive properties were measured by superconducting quantum interference device (SQUID:). The results of SQUID measurements indicate that the critical temperature (T-c) of the samples with Pt addition so produced with the oxygen heat treatment (623 K for 300 h) was 94 K and the critical current density (J(c)) was 2.3 x 10(4) A/cm(2) at 77 K, 0.2 T. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.