EQUILIBRIUM CRYSTAL SHAPE OF PLANAR ISING ANTIFERROMAGNETS IN EXTERNAL FIELDS

For square and honeycomb Ising antiferromagnets (AF) in external fields, one-dimensional (1 D) anisotropic interface tension and a 2 D equilibrium crystal shape (ECS) are calculated with high precision by a method using the free random walk with imaginary path-weights. The field dependence of interface entropy and interface stiffness are also shown. We apply the results to the stoichiometrically two components crystals of GaAs type. The relative vapor pressure dependence of anisotropic step tension and facet shape of the 3D ECS are obtained.