Molecular dynamics simulation of fast particle irradiation to the Gd2O3-doped CeO2

The structural relaxation caused by the high-energy-ion irradiation of CeO2 with Gd2O3 addition was simulated by the molecular dynamics method. The amount of Gd2O3 was changed from 0 to 25 mol% by 5 mol%. As the initial condition, high thermal energy was supplied to the individual atoms within a cylindrical region of nanometer-order radius located in the center of the specimen. The potential proposed by Inaba et al. was utilized to calculate interaction between atoms [H. Inaba, R. Sagawa, H. Hayashi, K. Kawamura, Solid State Ionics 122 (1999) 95–103]. The supplied thermal energy was first spent to change the crystal structure into an amorphous one within a short period of about 0.3 ps, then it dissipated in the specimen. By increasing the concentration of Gd2O3, more structural disorder was observed in the sample, which is consistent to the actual experiment.