Physisorption Kinetics from Mean-Field Theory: Compensation Effect near Monolayer Coverage

Abstract

Based on a set of nonlinear rate equations with phonon-mediated transition rates calculated from mean field theory, the coverage-dependent isothermal desorption time for $^{3}\mathrm{He}$ on graphite up to a coverage of 1.5 adlayers is determined. Prefactors in the Arrhenius parametrization drop by 2 orders of magnitude as the heat of adsorption decreases for increasing coverage, establishing a compensation effect in physisorption kinetics.