On the commensurate-incommensurate transition in adsorbed monolayers

A Monte Carlo simulation method is used to study the commensurate-incommensurate phase transition in monolayers and the formation of bilayer films on the (100) face of an fee crystal. The phase diagram for the system which forms the registered(1x1)and high density incommensurate phases in the monolayer has been determined. It is shown that the registered phase undergoes the transition to a denser incommensurate solid phase when the film density increases. The mechanism of melting of the monolayer film is found to depend on the film density. In particular, the melting of dense incommensurate solid monolayer film is found to be accompanied by the transfer of adsorbed molecules into the second layer. (C) 1999 Published by Elsevier Science B.V. All rights reserved.