Molecular dynamics study of self-radiation damage in Gd2Zr2O7 and Gd2Ti2O7 pyrochlores

Several theoretical investigations based on calculations of the energy of static configurations have been undertaken for explanation of the relation between the radiation resistance of pyrochlores and their chemical composition. The stability and radiation resistance of pyrochlores are related to the energy of point defect formation. The MD method consists in calculation of the trajectories of motion of all atoms of the system on the basis of Newton's second law. The calculations were carried out in the partially covalent approximation. The calculations carried out showed that the motion of the knocked on thorium atom with the energy of 15 keV results in its impact with other atoms of the system. These atoms are displaced from the equilibrium positions, begin to move, and, in turn, displace other atoms. This process results in the formation of the displaced atom cascade (DAC).