Monte Carlo study of linear chain submonolayer structures.Application to Li/W(112)

The lattice gas model for adsorption of alkaline elements on W(112) surface is studied by Monte Carlo simulations. The model includes dipole–dipole interaction as well as long-range indirect interaction. The numerical results show that truncation of the indirect interaction even at 200$\mathring{A}$ may change a phase diagram, i.e., new phases containing domain walls might occur. It is demonstrated that a defected phase can exist at high temperatures even if it is not stable at T=0. The phase diagram for Li/W(112) is constructed and long periodic chain structures (91), (61), (41), (31), and (2*1) are found to be stable at low temperatures. Role of thermal fluctuation is discussed by comparison of Monte Carlo results with mean field approximation results.