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HL: Halbleiterphysik

HL 24: Poster II

HL 24.111: Poster

Mittwoch, 25. März 1998, 10:30–19:00, A

Self-diffusion in SiC — •L. Torpo L. Torpo, M. Kaukonen, R. M. Nieminen and T. Frauenheim — Institut fuer Physik, Technische Universitaet, D-09107 Chemnitz — Laboratory of Physics, Helsinki University of Technology, FIN-02015 HUT, Finland

Employing a density-functional tight-binding (DF-TB) potential together with the quasi-harmonic method, we have investigated various diffusion pathways by calculating free-energy barriers for diffusion in 3C-SiC. Due to the restricted accuracy of the harmonic analysis in estimation of the phonon entropy in saddle-point configurations, some of the diffusion mechanisms are studied further by semi-empirical molecular dynamics (MD) simulations and subsequently evaluating the mean square displacement. The annealing temperature and migration properties of the silicon vacancy have been studied in detail in the framework of point defect assisted mechanism. The result are discussed in the context of recent ESR, PL and ODMR experiments.