The nature of the melting transition for a mixed monolayer system physisorbed onto graphite: Argon and krypton patch impurities

A constant density (rho = 1) constant temperature molecular dynamics method with periodic boundary conditions is utilized to examine the melting trans ition for argon impurity patches embedded in krypton monolayer matrixes las well as for the complement system) deposited onto graphite for various val ues of argon impurity fraction X. The character and temperature T-m of melt ing are found to be dependent on the impurity fraction as well as adsorbate topology vis-a-vis which species is the patch impurity and which is the ma trix. No phase separation is observed, as the melting temperature of the ma trix is coincident with that of the patch in all cases examined. Much of th e behavior exhibited by the system in this study can be understood by vacan cy formation arguments.