Interface structural evolution of YBa2Cu3Ox from a randomly oriented silver alloy substrate

Abstract In our previous work we have obtained YBCO thick films on silver alloy substrate (SAS) via the peritectic solidification. To identify the underlying mechanism of YBCO grain growth at the substrate interface, extensive transmission electron microscopy experiments were carried out in this study. A thin “buffer” of 300 nm thickness was observed between the YBCO film and the SAS. This “buffer” was identified to be essentially the YBCO structure, however lacking of the superlattice. Initially randomly oriented, these small crystallites in the buffer gradually grow into a large grain of YBCO within the polycrystalline film. The underlying mechanism of crystal evolution on an unoriented substrate is discussed.