TWO-DIMENSIONAL PHASE TRANSITION IN CHEMISORPTION SYSTEM - A MONTE CARLO SIMULATION

A simple 12-4-3 exp potential model is proposed to describe the interaction between adatoms. Two dimensional phase transition is studied by Monte Carlo simulation with lattice gas model in which the third nearest neighbor interaction is considered. Both the ( √3 x √3 ) -30°and the (2x2) structure are obtained under different coverages and temperatures. A limited T-θ phase diagram which is similar to that from experiment is obtained.