Simulations of the kinetic friction due to adsorbed surface layers

Simulations of the kinetic friction due to a layer of adsorbed molecules be tween two crystalline surfaces are presented. The adsorbed layer naturally produces friction that is consistent with Amontons' laws and insensitive to parameters that are not controlled in experiments. The kinetic friction ri ses logarithmically with velocity as in many experimental systems. Variatio ns with potential parameters and temperature follow variations in the stati c friction This correlation is understood through analogy with the Tomlinso n model and the trends are explained with a hard-sphere picture.