Lattice Dynamics of 2D Monoatomic Crystals: Application to 3He on Graphite

The dynamics of a two-dimensional rare gas crystal with triangular lattice is investigated theoretically. Phonon spectra of the 2D crystal are calculated within the model which takes into account the interaction between nearest neighbours in the layer and interaction of layer atoms with the substrate. On the basis of obtained results the temperature dependence of lattice heat capacity has been calculated and a comparison is made with experimental data.