Heavy ion irradiation-induced phase transformation in polycrystalline Dy2O3

Radiation damage effects in polycrystalline pellets of the rare earth sesquioxide Dy2O3 irradiated with 300 keV Kr2+ ions were studied by combining grazing incidence X-ray diffraction (GIXRD) with transmission electron microscopy (TEM). Radiation damage was introduced using 300 keV Kr2+ ions to fluences up to 1 × 1020 Kr m−2 at cryogenic temperature. GIXRD and cross-sectional TEM observations revealed that the crystal structure of the irradiated Dy2O3 transformed from a cubic, so-called C-type rare earth sesquioxide structure to a monoclinic, B-type rare earth sesquioxide structure upon ion irradiation. In addition, TEM and high-resolution electron microscopy (HREM) indicated that the transformed surface Dy2O3 layer adopts an epitaxial orientation relationship with the substrate Dy2O3.