Thin films of CuCrO have been grown on AlO (001) substrates by oxygen plasma assisted molecular beam epitaxy. With a substrate temperature of 700°C or 750°C, the films showed an unanticipated (015) orientation but at a higher substrate temperature of 800°C the expected basal (001) orientation predominates. The optical absorption spectrum of CuCrO shows a direct allowed absorption onset at 3.18eV together with a weak peak at 2.0eV which is suppressed by Sn doping. This suggests that the low energy peak should be attributed to 3d→3d excitations associated with Cu defect states rather than excitations localised on Cr. Valence band X-ray photoemission spectra of (001) and (015) oriented CuCrO are compared with those obtained from polycrystalline samples.
Shin, D., Foord, J. S., Egdell, R. G., & Walsh, A. (2012). Electronic structure of CuCrO2 thin films grown on Al2O3(001) by oxygen plasma assisted molecular beam epitaxy. Journal of Applied Physics, 112(11), . https://doi.org/10.1063/1.4768726