Effects of O@u2@u+ ions beam irradiation on crystal structure of rare earth sesquioxides

We report the results of ion irradiation influence on rare earth sesquioxides structure, which are materials of practical importance as a radiation resistant ceramics in nuclear applications. Y@d2O@d3, Gd@d2O@d3 and Er@d2O@d3 sesquioxides in the pellet form were irradiated by oxygen ions (O@u2@u+) beam with the energy of 30keV and implantation fluence of 5x10@u2@u0m@u-@u2. Samples are characterized by Grazing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy and atomic force microscopy (AFM). By GIXRD it was found partial transformation from cubic (C) to monoclinic (B) phase only in Gd@d2O@d3, induced by O@u2@u+ irradiation. This was confirmed by Raman spectroscopy. Although full phase transition from C to B phase in Y@d2O@d3 was not observed, the splitting and broadening of the main intensity Raman band for C phase could be explained by the stress and the disorder induced by the quenching. Analysis done by AFM showed changes in surface topology, i.e. values of average roughness (Ra) and root mean squared roughness (RMS) were significantly changed after irradiation for all samples. RMSs in Y@d2O@d3 before and after irradiation were 35nm and 26nm, respectively.