Preparation of epitaxial V2O3 films on C-, A- and R-planes of alpha-Al2O3 substrates by coating-pyrolysis process

Citation
I. Yamaguchi et al., Preparation of epitaxial V2O3 films on C-, A- and R-planes of alpha-Al2O3 substrates by coating-pyrolysis process, THIN SOL FI, 366(1-2), 2000, pp. 294-301
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
THIN SOLID FILMS
ISSN journal
0040-6090 → ACNP
Volume
366
Issue
1-2
Year of publication
2000
Pages
294 - 301
Database
ISI
SICI code
0040-6090(20000501)366:1-2<294:POEVFO>2.0.ZU;2-A
Abstract
Epitaxial films of vanadium(III) oxide V2O3 were prepared on the C-, A-, an d R-planes of alpha-Al2O3 substrates by a coating-pyrolysis process. The fi nal heat treatment was carried out at 1000 degrees C in a precisely control led gas how of a CO-CO2 mixture (pCO/pCO(2) = 10(-1)) at ambient pressure. This condition corresponds to an oxygen partial pressure of similar to 10(- 12) atm. The X-ray diffraction theta-2 theta scanning and pole-figure analy sis showed that the 0.5-mu m-thick V2O3 films chiefly comprise the grains g rown epitaxially to the substrate surfaces and a small amount of uniaxially oriented crystallites with the c-axis perpendicular to the substrate surfa ces. In the films grown on the C- and A-planes of alpha-Al2O3, epitaxial gr ains grown 60 degrees-rotated in the basal plane relative to the substrates (or 180 degrees domains) were also present. The occurrence of the uniaxial ly c-axis-oriented and 180 degrees domains may be attributed to the crystal lization from the film surf;ice accompanying the reduction of the precursor s, which contain higher-valence vanadium ions, by the GO-CO: mixed gas, whe reas the epitaxial grains grow from the film/substrate interface. (C) 2000 Elsevier Science S.A. All rights reserved.