Role of ion species in radiation effects of Lu2Ti2O7 pyrochlore

In an attempt to investigate the role of ion species in the radiation effects of pyrochlores, polycrystalline Lu2Ti2O7 samples, prepared through a standard solid state process, were irradiated with three different ion beams: 400 keV Ne2+, 2.7 MeV Ar11+ and 6.5 MeV Xe26+. To characterize the damaged layers in Lu2Ti2O7, the grazing incident X-ray diffraction technique was applied. All the three irradiations induce significant amorphization processes and lattice swelling in Lu2Ti2O7. However, when the ion fluence is converted to a standard dose in dpa, the radiation effects of Lu2Ti2O7 show a great dependence on the implanted ion species. The threshold amorphization dose decreases with increasing ion mass and energy. Besides, the amorphization rate, as well as lattice swelling rate, increases with increasing ion mass and energy. That is, the Lu2Ti2O7 pyrochlore is more susceptible to amorphization and lattice swelling under heavier ion irradiation. These results are then discussed in the framework of defect configuration and the density of collision cascades based on Monte Carlo simulations.