VIBRATIONAL PROPERTIES OF AN ADSORBED SURFACE LAYER ON A SIMPLE MODEL CRYSTAL

We consider the influence of an adsorbed layer of atoms on the vibrational properties of a simple model crystal. The change in a specific heat and entropy are computer for arbitrary temperatures, assuming the defect layer differs only in mass from the atoms in the bulk crystal. The Montroll-Potts model of latti dynamics is used for this purpose. We also explore the existence of surface modes above the vibrational band of the host matrix for this model, along with in-band resonances and low frequency surfaces modes. The results of the specific heat and entropy calculation are compared with an expansion valid in the high temperature regime. © 1969.