Machine simulation of collisions between a copper atom and a copper lattice

Abstract

We have examined a number of collision events in which the target atom is embedded in a crystal lattice. The fcc <100>, <110>, and <111> orientations were examined in detail for the energy range from 25 eV to 10 keV. Preliminary results for the bcc <100> lattice are included. Lattice effects are somewhat smaller than one might anticipate. Orientation effects are significant because the relative atomic separations vary considerably between different orientations. The general features of our results are insensitive to the form of interaction potential, but magnitudes vary considerably. For the Gibson No. 2 parameters in a Born-Mayer potential, lattice effects lose significance around 5-keV bombardment energy; for the Gibson No. 1 they persist to at least 10 keV. No "effective mass" behavior was detectable. Binary-collision theories are not valid for energies below a few hundred eV.