Enhanced flux pinning in MOD YBa2Cu3O7−δ films by ion milling through anodic alumina templates

Abstract

A straightforward and reproducible method has been developed for creating < 100 nm wide, 400–600 nm long c-axis columnar defects in fluorine-free MOD YBCO films (∼700 nm thick) using ion milling through free-standing nanoporous anodic aluminum oxide membranes positioned in contact with the films. At 77.3 K, a moderate Jc increase of ∼50% was achieved in self-field, whereas at 1 T a more than doubling of Jc was observed along ab, part of this enhancement coming from uncorrelated pinning effective over all field directions. X-ray analysis confirmed an additional in-plane microstrain component which can be attributed to oxygen disorder induced during the ion milling process.