Angular Forces and Normal Vibrations in Platinum

Abstract

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.

Non-central forces and normal modes of vibration in palladium

“…Keeping the above facts in view, it is interesting to note that the present approach, whilst taking into account the effect of electron gas in a rather primitive way and assuming short range interactions effective up to second nearest neighbours only, predicts reasonably well the dynamical properties of palladium. Though the present study is confined to the crystal dynamics of Pd only, our results are surprisingly good especially in case of Ni and Pt (20,21). All these three metals (Pd, Ni, Pt) form the same vertical group of the periodic table.…”

Many Body Interactions and Lattice Dynamics of Gold

“…On the basis of non-central force model, Machado and Shukla(1976) also evaluated lattice specifi c heat of gold. Kharoo et al (1977) exploited the improved CGW model with Kreb's type volume force to calculate specifi c heat of gold. Thakur and Singh (1986) reported results of specifi c heat capacity of gold accurately within the range of 15-300k and results obtained satisfi ed the earlier experimental results of Culsius and Hartek (1928).…”

“…Theoretical study of lattice dynamics of metals has been done by various workers by using phenomenological models and pseudo potential approaches. Closs and Shukla (1977), Kumar and Jokadi (1975), Machado and Shukla (1976), Rathore(1977), Bertolo and shukla(1975), Rai and Hemkar(1976), Kharoo et al (1977), Thakur and Singh (1986). Singh and Prakash (1975) studied lattice dynamics of gold using model potential or pseudo potential approaches.…”