Evaluation of the specific heat of diamond from its Raman frequencies

Abstract

The specific heat of diamond is evaluated from the knowledge of its vibration spectrum obtained principally from Raman effect studies. The vibration spectrum is known to consist of eight discrete monochromatic frequencies followed by a continuous spectrum of elastic vibrations. Accordingly, the specific heat is expressed as the sum of eight Einstein functions, supplemented by three Debye functions representing respectively the three types of elastic vibration possible in the crystal. A close agreement is found between the calculated and the experimental values over the entire range of temperatures between 70°K and 1100°K, which is all the more significant in view of the calculations being completely independent of the specific heat data themselves.