Evidence of Mobile Ag and Growth Mechanism of YBa2Cu3O7-y Films Deposited on Cube Textured Ag Tape by Chemical Vapor Deposition

YBa2Cu3O7-y (YBCO) films were prepared on {100} cube textured Ag tape (CUTE-Ag tape) by metal organic chemical vapor deposition (MOCVD) using a liquid state metal organic (MO) source. Numerous spiral steps accompanied by screw dislocations were observed and many particles were observed on the terrace surface of the spiral steps by atomic force microscopy (AFM). We observed a change in surface morphology before and after heat treatment in vacuum at 550°C. After heat treatment, these particles became smaller and concentrated at the edge of the spiral steps. We confirmed by scanning Auger microscopy that the main composition of these particles was Ag. We propose a growth mechanism on a Ag substrate in which Ag segregates to the surface and acts as surfactant for YBCO growth.