Microstructure and interface phase formation in YBa2Cu3O7-δ prepared by an MOD process

Understanding the evolution of microstructure in YBCO (YBa(2)Cu(3)O7-delta) is critical to optimizing the process for production of high quality superconducting wire for commercial applications. Therefore, microstructure and interfaces have been investigated in fully reacted YBa2Cu3O7-delta, prepared by the metalorganic deposition (MOD) process, and deposited on CeO2/YSZ/Y2O3/NiW. YBCO nucleates on CeO2 with a specific orientation relationship where [011] CeO2 parallel to [100]YBCO and(200) CeO2 parallel to(002)YBCO, and with the [001] YBCO axis parallel to the film growth direction. A 25-50 nm thick reaction layer of BaCeO3 was observed at the YBCO : CeO2 interface. Formation of this layer releases a considerable amount of Cu and Y into the YBCO matrix. Details of the interfacial phase formation in the MOD-processed YBCO films are presented in this paper.