Phase transformations in Y2O3 thin films under swift Xe ions irradiation

Yttrium oxide (Y2O3) thin films deposited on silicon (Si) by an ion beam sputtering technique have been irradiated by 92 MeV xenon ions at room temperature. The microstructure of the irradiated thin film has been studied by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). A complete structural conversion from the cubic C-type to a monoclinic B-type phase is obtained. These results were compared with the phase transformation obtained in Y2O3 thin films by medium energy Xe ion irradiation. In both cases the oxygen network behaviour under irradiation is the key parameter of the phase transformation.