FINITE-SIZE DEPENDENCE OF THE TRACER SURFACE-DIFFUSION COEFFICIENT NEAR A 2ND-ORDER PHASE-TRANSITION

We investigate the finite size dependences of the tracer surface diffu sion coefficient in the vicinity of a second order phase transition. F or this purpose, we use a lattice gas model of repulsively interacting particles on a square lattice. For all lattice sizes L studied, the t racer diffusion coefficient, D-t, is a smooth function of temperature. There are no anomalies in the direct temperature dependence of D-t ne ar the critical temperature T-c. However, its derivative, dD(t)/d(1/k( B)T), exhibits cusp-like anomalies which are largely pronounced for la rge lattice sizes.