Oxidation of c-axis-oriented epitaxial YBa2Cu3O7–δ thin films in ozone-containing atmospheres

• Published in: Journal of materials research Vol. 17; no. 4; pp. 884 - 889
• Main Authors: Gibbons, B. J., Eom, C. B., Rao, R. A., Trolier-McKinstry, S., Schlom, D. G.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.04.2002
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/JMR.2002.0128

Oxygen diffusion into c-axis-oriented YBa2Cu3O7-δ epitaxial thin films was observed using real-time spectroscopic ellipsometry. The experiments were conducted under controlled atmospheres of 10% O3/90% O2 and 80% O3/20% O2. At 2 × 10-5 torr, oxidation of the films began at temperatures as low as 100–125 °C for heating rates ≤3 °C/min. Full oxidation was seen by 190 °C at these rates. Based on these data, the activation energy of oxygen diffusion into YBa2Cu3O7-δ from an ozone/oxygen atmosphere was found to be between 0.43 and 0.52 eV. This was appreciably smaller than for in-diffusion in a molecular oxygen atmosphere. Higher ozone content atmospheres did not improve the oxidation kinetics. These atmospheres did, however, delay the onset of reduction in the films by 60–70 °C at higher temperatures.