Effects of target microstructure on pulsed laser deposited YBa2Cu3O7-deltathin films

Superconducting YBa2Cu3O7-delta thin films were prepared by pulsed laser de position using two targets; one was fabricated by solid-state sintering (SS S) and the other was fabricated by modified melt-textured growth (MTG). Mic rostructures of the targets and the films were investigated using X-ray dif fraction and scanning electron microscopy. Also, superconducting properties of the films were examined by electrical measurements. When compared with SSS targets, MTG targets showed a denser microstructure consisting of large r grains, and the surfaces of MTG targets were less modified with the cumul ative laser incidence. The films deposited from MTG targets showed better-a ligned c-axis orientation, a higher density microstructure, and exhibited e nhanced superconducting properties as compared to the films prepared from S SS targets. These results were ascribed to higher kinetic energies and an i mproved uniformity of the vapor species ejected from MTG targets. (C) 2000 published by Elsevier Science S.A. All rights reserved.