PNNL

Abstract

This paper reports on precipitation of metallic particles in CeO2, a surrogate for UO2. Pulsed laser deposition was used to grow polycrystalline CeO2 films doped with 2 wt.% Mo, 0.75 wt.% Pd, 0.25 wt.% Rh, 1.5 wt.% Ru and 0.5 wt.% Re. The dopants are uniformly distributed in CeO2 in the as-grown samples. He+ ion irradiation at 673 K leads to formation of Pd nanoparticles in the CeO2 matrix. In-situ irradiation transmission electron microscopy at room temperature does not provide any evidence of particle precipitation. Epsilon particles containing the 5 metallic dopants are observed in both the as-grown and He+ ion irradiated CeO2 after thermal annealing at 1273 K.