In this paper we study the problem of lattice stability of the heavier rare gas solids (i.e. Ar, Kr, Xe) in terms of the reduced second-order self-consistent approximation, developed by Plakida and Siklos on the basis of the double- time Green's functions method. As a model of interatomic interactions we take the (n,m) Lennard-Jones, (exp,m) Buckingham and (exp,exp) Morse pair potentials with the parameters determined self-consistently with the help of the experimental data for the zero-point lattice constant, energy of sublimation and isothermal compressibility. Apart from the pressure variations of the limiting temperature of stability we also investigate the behavior of selected thermodynamical properties of crystal near the limit of stability. The mentioned theoretical results are compared with available experimental data.
|