Ab initio prediction of threshold displacement energies in ZrC

The threshold displacement energies (Ed) of C and Zr atoms in ZrC have been determined using ab initio molecular dynamics simulation. The values of Ed have been predicted along the three main high-symmetry crystallographic directions [001], [011], and [111], and the averaged Ed values are 16 eV and 37 eV for the C and Si sublattices, respectively. We further explore the dependence of Ed on small deviations from these high-symmetry directions and on the presence of C vacancies, which are often encountered in ZrCx alloys. The trends in values are explained in terms of the structural and chemical properties of ZrC. The predicted Ed values provide relevant parameters for future modeling of radiation damage in ZrC.