POTENTIAL-ENERGY OF 2 STRUCTURES OF SIGMA = 11(011) TILT GRAIN-BOUNDARY IN SILICON AND GERMANIUM WITH EMPIRICAL POTENTIALS AND TIGHT-BINDING METHODS

Two atomic structures A and B of the Sigma = 11(0 1 1) grain boundary were observed in silicon and germanium. We have performed a complete s tudy of the stability of these two grain boundaries using some empiric al potentials and also the semiempirical, tight-binding (TB) method. T he TB method has confirmed the experimental observations at low temper atures. The A structure is more stable in silicon whereas for germaniu m the B structure is obtained. The empirical potentials, such as those of Keating (1966), Baraff et al. (1980) and of Stillinger and Weber ( 1985), give the A structure as the most stable for both anium and sili con. The non-ability of these empirical potentials to make a differenc e between germanium and silicon and the advantage of TB method are dis cussed. Copyright (C) 1998 Elsevier Science B.V.