COMPUTER-SIMULATION OF AMMONIA ON GRAPHITE .2. MONOLAYER MELTING

Molecular dynamics simulations of monolayers of ammonia adsorbed on graphite are reported. The interaction potentials used were discussed in paper I. Temperatures were chosen to include melting and the orientational disordering. It is shown that orientational disordering in the systems studied is a gradual process which is nearly complete at temperatures below the layer melting point. Melting occurs at 145 ± 5 K for a submonolayer coverage and at 180 ± 5 K for a complete layer. These results are in moderately good agreement with the available experimental data. Possible reasons for the observed discrepancies are discussed. © 1990 American Institute of Physics.