YBa 2Cu 3O 7−δ films with self-organized natural linear defects

Abstract

Recently [1], we have shown that dislocations act as strong pinning sites for vortices in YBa 2Cu 3O 7−δ films. Using a wet-chemical etching technique in combination with Atomic Force Microscopy, we investigate the distribution of these natural linear defects in laser ablated films. We find that: (i) dislocations are induced in the early stages of film growth at the substrate-film interface and persist up to the film surface, resulting in a uniform length distribution and (ii) the in-plane defect distribution exhibits short-range ordering. This self-organization makes films completely different from e.g. single crystals with artificial columnar defects.