|About this Abstract
||MS&T23: Materials Science & Technology
||Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments IV
||Structural Stability of REE-PO4 (REE=Sm,Tb) under Swift Heavy Ion Irradiation
||Cale C. Overstreet, Eric O'Quinn, William Cureton, Julia Leys, Guido Deissmann, Stefan Neumeier, Chien-Hung Chen, Maik Lang
|On-Site Speaker (Planned)
||Cale C. Overstreet
Rare earth element (REE) phosphates are a type of naturally occurring minerals that exhibit excellent tolerance to prolonged self-irradiation which makes them an attractive candidate material for disposal of long-lived radionuclides. Here, we show that SmPO4 (monazite, P21/n) and TbPO4 (xenotime, I41/amd) exhibit a very similar response to swift heavy ion irradiation despite different starting structures. SmPO4 and TbPO4 were simultaneously irradiated with 1.1 GeV Au ions and analyzed using synchrotron-based X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. The radiation response was evaluated by deconvoluting peaks in collected XRD patterns to obtain crystalline and amorphous phase fractions at each irradiation fluence. A direct-impact model best described the amorphization process and was used to determine the amorphous cross section and track diameter. Amorphization within individual tracks was confirmed by TEM imaging with good track size agreement. Raman spectroscopy qualitatively confirmed the ion-induced crystalline-to-amorphous transformation for both phosphates.