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A lattice dynamical study of platinum has been made on the basis of the improved Clark-Gazis-Wallis model considering volume forces of Krebs' nature. The phonon dispersion relations obtained for the three symmetry directions have been compared with the recent inelastic neutron scattering experiments. The specific heat at constant volume has been calculated by Blackman's root sampling technique for temperatures above Θ/10, and below this temperature the calculations are carried out by employing the modified Houston spherical six-term integration procedure. The computed lattice specific heats in terms of the effective Debye temperatures Θ are compared with the available calorimetric data. The theory is in good agreement with the experimental data.

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A technique to improve the epitaxial growth of some fcc and bcc metals on rock salt An analysis of the temperature dependence of Griineisen parameters of copper, silver, gold, and aluminium is performed in terms of the elastic constants and their pressure derivatives by a new lattice dynamical model. The model satisfies the symmetry requirements of the lattice and the lattice is in eqUilibrium without recourse to external forces. The microscopic Griineisen parameters Yqj are calculated as a function of wave vector q, along the principal symmetry directions, (100), (110), (III), (210), (211), and (221), and the values are averaged over the wave vector space in the first Brillouin zone. For the evaluation of integrals, the modified Houston's method is used. The Griineisen parameters computed in our present study show reasonably satisfactory agreement with experimental measurements.

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