The relation between the defect structure, the surface roughness and the growth conditions of YBa₂Cu₃O_7-δ films

Abstract

YBa₂Cu₃O_7-δ films on SrTiO₃ are characterized by a network of anti-phase boundaries (APB's), protruding from the interface to the film surface. We propose that the island morphology of these films is to a large extent determined by this network. At APB-outcrops deep trenches form which separate the growth islands. At the cross-section of three APB's deep holes are formed. It is found that the growth island size can be increased by increasing the substrate temperature or the oxygen pressure during growth.