Direct morphology evidence of two-dimensional growth mode in pulsed-laser deposited YBa2Cu3O7-δ thin films

Abstract

Direct evidence of two-dimensional (2D) nucleation and growth mode in laser-ablated c-axis YBa2Cu3O7-δ film deposited on (100) LaAlO3 substrate was observed. The film consisted of uniform rectangle-shaped grains aligning well along the directions of in-plane a/b-axes. The surface of the film was free of growth spirals and almost free of droplets. It showed that the 2D-nucleation and growth mode dominated the entire film deposition process. The film had Jc values in the order of 106 A/cm2 at 77 K, implying that unknown pinning centers other than the screw dislocations should exist. © 1998 Elsevier Science Ltd. All rights reserved.