EFFECT OF A SYSTEMATIC VARIATION OF ND4BA2CU2O10 CONTENT ON THE MICROSTRUCTURE OF MELT-PROCESSED NDBA2CU3O7-DELTA SUPERCONDUCTOR

NdBa2Cu3O7-delta superconductor is melt processed in flowing argon gas of high purity, with systematically increasing Nd4Ba2Cu2O10 (Nd-422) content. The changes in the morphology and size of the Nd-422 inclusio ns in the Nd-123 matrix are studied and compared with those observed e lsewhere in the Y-123 system. An explanation for these variations is o btained by studying the microstructural features at the stage of incon gruent melting. Microstructural features such as width of the platelet s, the nature of interplatelet gaps, etc., are also studied as a funct ion of Nd-422 content. (C) 1998 Elsevier Science B.V. All rights reser ved.