Comparison among the growth mechanisms of stacking fault, twin lamella and screw dislocation: a Monte Carlo simulation

Abstract

A computer simulation method is employed to simulate the growth of an fcc (111) crystal surface, on which emerged the outcrops of a stacking fault, two types of twin lamella [Nai-Ben Ming and J. Sunagawa, J. Crystal Growth 91 (1988) 11] bounded by two partial dislocations and a dipole screw dislocation, respectively. A comparison is made among the stacking fault mechanism (SFM), twin lamella mechanism (TLM) and screw dislocation mechanism (SDM). It is found that SDM is more active than SFM and TLM at low supersaturation. The values of critical supersaturation Δμ∗ kT under which SDM is more active than SFM or TLM are obtained at different temperatures. Δμ∗ kT increases as the temperature is lowered. For B-type TLM, the effect of the size of the twinned area on the activity of the defect mechanism is discussed.