DISPLACEMENT THRESHOLD ENERGIES IN BETA-SIC

We have calculated the displacement threshold energies (E-d) for C and Si primary knock-on atoms (PKA) in beta-SIC using molecular dynamic s imulations. The interactions between atoms were modeled using a modifi ed form of the Tersoff potential in combination with a realistic repul sive potential obtained from density-functional theory calculations. T he simulation cell was cubic, contained 8000 atoms and had periodic bo undaries. The temperature of the simulation was about 150 K. Our resul ts indicate strong anisotropy in the E-d values for both Si and C PKA. The displacement threshold for Si varies from about 36 eV along [001] to 113 eV along [111], while E-d for C varies from 28 eV along [111] to 71 eV along [111]. These results are in good agreement with experim ental observations. (C) 1998 Elsevier Science B.V.