Dynamic and kinetic properties of point defects in γ U-10Mo: a molecular dynamics study

Controlled defects population and their movement constitute the foundation for describing micro-structural evolution in any material systems for nuclear applications. Molecular dynamics (MD) simulations were performed to study temperature (1200-1400 K) dependent displacement cascades with a U primary knock on atom (pka) carrying 2 keV kinetic energy in gamma U-10Mo. We observed a strong impact of the temperature on the population of point defects. The impact of kinetic energy of the pka on the number of survived and maximum point defects is addressed carefully where an increase in the number of defects led to an increase in the energy. Nudged elastic band (NEB) calculations were involved to calculate the activation energies of self-interstitial Mo for different intra and inter-planar transitions. The transitions between < 011 > to < 011 >, < 001 > to < 011 >. < 001 > to < 111 >, < 111 > to < 001 > and < 111 > to < 110 > Mo-Mo dumbbell configurations were explored. The impact of applied strains on the activation energy in each case of the transitions was investigated where irregular behavior in the energy with rise in the strain was observed.

Automated summary

Controlled defects population and their movement are essential for understanding micro-structural evolution in nuclear materials. Molecular dynamics simulations were used to study the effects of temperature and kinetic energy on displacement cascades and point defect populations. Nudged Elastic Band calculations were performed to determine the activation energy for inter and intra-planar transitions of self-interstitial Mo, and the impact of applied strains on the transition energies was investigated.