Calculated phase boundary including corrugation effects for krypton layersphysisorbed onto spherical substrates - art. no. 205425

A molecular-dynamics technique is utilized to calculate the melting curve o f submonolayer and complete layers of krypton atoms physisorbed onto a sphe rical substrate. Two models of the substrate are used. In the first model t he substrate is treated as a spherical continuum whose differential element s interact with krypton atoms via Lennard-Jones (LJ) potential. Hysteresis is present in the melting transition for low coverages, which disappears as the melting becomes more gradual near complete coverage. The melting tempe rature at completion is very sensitive to second-layer promotion, which in turn depends strongly on the radial boundary conditions. In the second mode l the melting transition is also examined for 100 Kr atoms adsorbed onto sp heres that exhibit corrugation in their potential interactions with the asd orbate. Addition of corrugation in the form of a C-60 lattice effectively s erves to merely raise the average LJ substrate sphere density slightly and leave the melting transition unaffected, but replacing the LJ sphere with a cubic carbon lattice raises the melting temperature by about 3 K (4.6%) wh ile dramatically affecting the desorption behavior of the adlayer and lower ing its spatial order. Various bond-orientational distributions and snapsho t configurations are employed in understanding the completion process.