Brookhaven National Laboratory, Upton, N. Y.
Pages: 19 Published: Jan 1964
High-speed computer studies on the dynamics of a set of several hundred atoms interacting with realistic forces and simulating an initially perfect crystalline lattice which undergoes radiation damage have been in progress at Brookhaven National Laboratory in recent years. Reports have been published by Vineyard and co-workers on calculations made so far on a model representing copper, a face-centered cubic metal. These calculations have now been extended to a body-centered cubic lattice simulating α-iron. Several types of interatomic potentials have been tried: potential I, the Born-Mayer type; potential II, a Morse potential derived by Girifalco and Weizer, but in which the potential has been cut off between the second and third neighbors; and potential III, which also has a repulsive front and an attractive tail, but is not a single analytical function of interatomic separation. At close interatomic separations, potential III approaches the potential derived by Abrahamson on the basis of the Thomas-Fermi-Dirac statistical model of the atom. The correlation between the displacement threshold energy and the initial direction of the knock-on is discussed along with the probability of displacing an atom.
Paper ID: STP45823S