Study of the stability of the structural properties of CeO2 microparticles to helium irradiation

The work is devoted to the study of the radiation resistance of CeO2 microparticles to irradiation with low-energy He2+ ions with an energy of 40 keV, the irradiation fluence was 10(15)-10(16) ion/cm(2). The study found that, in contrast to the initial spherical microparticles, irradiated microparticles are a mixture of sintered sphere-like agglomerates, with porous inclusions. According to energy dispersive analysis, an increase in the irradiation fluence leads to an increase in the oxygen content and its uneven distribution over the structure, which leads to a violation of the stoichiometry of the microparticles under study. It was found that the displacement of atoms from the lattice sites as a result of irradiation, as well as their subsequent migration, leads to a change in interplanar spacings and the appearance of distortions and deformations of the crystal lattice. According to X-ray diffraction data, changes in the crystal structure of the microparticles under study are associated with deformation and distortion of the crystal structure due to migration of defects and an increase in the vacancy density of oxygen defects, as well as partial swelling of the crystal structure.