NON-c-AXIS-ORIENTED EuBa2Cu3O7-delta THIN FILMS GROWN ON Al2O3(1-102) SUBSTRATES WITH CeO2 BUFFER LAYERS

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 38, no. 10, pp. 5857-5862. 1999 Part 1. Vol. 38, no. 10, pp. 5857-5862. 1999, 1999-01, Vol.38 (10), p.5857-5862
• Main Authors: Wakana, H, Yokosawa, A, Michikami, O
• Format: Article
• Language: English
• ISSN: 0021-4922
• DOI: 10.1143/jjap.38.5857

EuBa2Cu3O7-delta (EBCO) thin films with different growth orientations were prepared on Al2O3(1-102) substrates with CeO2 buffer layers by dc magnetron sputtering. The EBCO thin films were deposited immediately after off-axis rf magnetron sputtering of CeO2(001) films. The effects of substrate temperature and O concent on epitaxial orientation of EBCO thin films were examined. With the increase in O concentration, the surface roughness of an EBCO thin film increased. An appropriate O concentration existed. It was clarified that the orientation of an EBCO thin film depended on CeO2 film thickness. The (100)- and (110)-oriented EBCO thin films were obtained on CeO2 buffer layers 30-90 angstroms thick and > 700 angstroms thick, resp. The (100)- and (110)-oriented EBCO films had in-plane epitaxial orientation relationships. The (100)-oriented EBCO films deposited on 50-angstrom-thick CeO2 (001) buffer layers had Tce's of 72.0 K, and (110)-oriented EBCO films deposited on 750-angstrom-thick CeO2(001) buffer layers had Tce's of 70.0 K. The Tce decreased with increasing CeO2 buffer layer thickness above 800 angstroms. The a-axis-oriented EBCO thin films exhibited Tce's of about 85.4 K on the 50-angstroms-thick CeO2 buffer layers prepared by a self-template method. 14 refs.