MOLECULAR DYNAMICS STUDY OF HIGH-TEMPERATURE GRAIN-BOUNDARY STABILITY IN A (100) Σ = 29 BICRYSTAL MODEL

A new molecular dynamics program for the investigation of planar bicrystalline interfaces at high temperature and finite external stress has been developed. The constant-stress (Parrinello-Rahman) method is combined with a Region I-Region II treatment of the borders, thus avoiding (1) 3d-periodic border conditions (and therefore the presence of two interfaces in the computational unit cell) and (2) unphysical constraints arising from fixed borders. The usefulness of this new ''semi-periodic border'' treatment is illustrated in an investigation of the high-temperature stability and structure of the ..sigma.. = 29 (100) twist grain boundary. 7 refs., 5 figs.