Calculation of lattice specific heat of bcc NbZr dilute alloy

Abstract

The lattice specific heat at very low temperatures, using a perturbation model which includes the mass change and change in the nearest-neighbour force constants due to interaction between impurity and host atoms has been calculated. In addition to the local perturbation due to mass change and force-constant changes, the effect of volume change has also been taken into account. The calculated results have been compared with the experimental measurements and values of central and non-central force-constant changes have been obtained. The increase in lattice specific heat is explained on the basis of these force-constant changes. The possibility of occurrence of resonance and localized modes from the calculation of resonant denominator have been investigated.