Molecular dynamics simulation of point defect accumulation in MgAl2O4

The kinetics of phase transformation under irradiation of magnesium aluminate spinel MgAl2O4 has been investigated by means of continuous Frenkel pair introduction in the framework of empirical potential molecular dynamics simulations. Phase transformation to defective rock-salt structure was observed with a cation displacement dose rate of 5 × 108 dpc/s (dpc: displacements per cation) at temperatures ranging from 30 to 2200 K. The critical dose for the phase transformation is in the range of 0.5–2.5 dpc, and it is prolonged with increasing temperature. No amorphization was realized in the simulations at 30 K up to a dose of 68 dpc with an accelerated displacement dose rate of 5 × 109 dpc/s.