Structure and phase component of ZrO2 thin films studied by Raman spectroscopy and X-ray diffraction

Zirconia (ZrO2) thin films were deposited by RF magnetron sputtering on zircaloy-4 (Zy-4) substrates directly from the ZrO2 target. These thin films, deposited at different substrate temperatures from 40 to 800 deg. C and within different times from 10 to 240 min, were investigated by Raman spectroscopy and by X-ray diffraction (XRD). A rather good agreement between the results given by the two techniques was obtained. By comparison between the Raman studies on zirconia thin films and on bulk zirconia, it is possible to conclude the following: (i) films are polycrystalline; (ii) ZrO2 is not completely dissociated during the deposition process; (iii) the structure and phase composition of the films depend on the substrate temperature and on the deposition time, thickness and, therefore, vary as a function of the distance from the film surface