Primary damage formation in Mo was investigated by using molecular dynamics simulations with embedded-defect and embedded-atom method interatomic potentials. The former was similar in nature to the latter, but included an approximate treatment of bond directionality in the many-body interaction. Molecular dynamics simulations were used to calculate the threshold displacement energy as functions of the crystallographic orientation and displacement cascade evolution resulting from primary knock-on atoms with energies ranging from 0.5 to 50keV. The defect structures which were produced with increasing primary knock-on atom energy were analyzed, and the results obtained were compared for the 2 potentials and with published simulation data for other body-centered cubic materials. The embedded-defect approach was found to be in better agreement with experimental findings on threshold energy. It also predicted larger vacancy clusters, as well as a larger fraction of clustered vacancies, than did the embedded-atom method. This seemed to be more consistent with experiment. Inelastic losses which were coupled with the thermal spike affected defect production in subtle ways; especially at higher energies. This did not seem to have been realized before.

Primary Damage Formation in Molybdenum - a Computer Simulation Study. R.Pasianot, M.Alurralde, A.Almazouzi: Philosophical Magazine A, 2002, 82[9], 1671-89