| The safe disposal of nuclear waste, is not only one of the key factors restricting the sustainable development of nuclear power, but also one of hotspots in research of nuclear science and technology. Perovskite oxides are the potential host material for immobilization nuclear waste, and SrTiO3of perovskite oxides is usually used in immobilization90Sr and actinide elements due to its outstanding physical and chemical properties.In this paper, the polycrystal SrTiO3specimens were prepared by using solid state sintering.400keV Ne ions were used to irradiate perovskite SrTiO3under liquid nitrogen (LN2) and room temperature (RT) conditions. The irradiated fluences are7×1014cm-2,1×1015cm-2,5×1015cm-2,1×1016cm2and2×1016cm-2. And the micro-structural transformation of the SrTiO3induced by Ne ion irradiation was systematically investigated by employing grazing incident X-ray diffraction (GIXRD) technique.The analysis results of GIXRD spectrum show that:1) The obvious amorphization was observed at1×1016cm-2under LN2. And there was no amorphization phenomenon at1×1016cm-2, even at2X1016cm-2under RT.2) The GIXRD diffraction patterns of the irradiated SrTiO3under RT have the similar characteristics to that under LN2temperature irradiation, except that the peak shifts under RT is not as obvious as those under LN2for the same ion fluence irradiation.3) The SrTiO3was irradiated under LN2, and it reflects the effects of volume swelling after. The irradiation effect of SrTiO3showed no evident volume swelling.To elucidate the experimental observations, the Materials Studio and the VASP were performed to calculate the likely defects and their formation energies for SrTiO3, which are based on first principles density functional theory. Comparing the theoretical calculation results and the experimental phenomena, conclude that the experimental phenomenon in the irradiated SrTiO3layer was likely caused by the relaxations of the Sr and Ti cations surrounding the accumulated vacancies on the oxygen sublattices. |
PDF Full Text Request