Swift heavy ion irradiation induced nanoparticle formation in CeO2 thin films

Nanoparticle formation in the, rf-sputtering grown, polycrystalline CeO2 thin films is achieved by the swift heavy ion (SHI) irradiation. Crystal structure and phases present in the as-grown and irradiated thin films are investigated by the X-ray diffraction (XRD) measurements. Irradiation induced formation of spherically shaped nanostructures, on the film surface, is confirmed by the atomic force microscopy (AFM). The Raman spectra of the irradiated samples show increased line-width and peak position shifting in the Raman active mode (F2g) of CeO2, indicative of the nanocrystallization in the irradiated CeO2 thin films. Formation of nanostructures in the irradiated samples is also briefly discussed in the light of ion energy and energy loss mechanisms.