Heavy ion irradiation-induced phase transformation in polycrystalline Dy₂O₃

Abstract

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.

Acknowledgments

This work was sponsored by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. P. Lu wishes to express his gratitude to the University of New Mexico for the use of their electron microscopy facility.