Hysteresis of the metal-insulator transition of VO2; evidence of the influence of microscopic texturation

Vanadium dioxide films have been deposited on silicon substrates by reactiv e RF cathodic sputtering from V2O4 and V2O5 targets. The optical measuremen ts show a good contrast at the semiconductor-metal transition, but exhibit two kinds of hysteresis cycle: a narrow and symmetrical one, and a wider an d asymmetrical one. We have mainly studied the microstructure of these samp les by means of grazing-incidence x-ray diffraction at the LURE synchrotron radiation facility. We analysed in detail the intensities of the diffracti on peak spectra and of the portions of diffraction rings. We found a clear relation between a narrow and symmetrical hysteresis cycle, and a (011) tex ture of the films. We attribute this result to an improvement in the cooper ativity of the transition phenomena.