Determining the phonon density of states from specific heat measurements via maximumentropy methods

Abstract

The maximum entropy and reverse Monte Carlo methods are applied to the computation ofthe phonon density of states (DOS) from heat capacity data. The approach isintroduced and the formalism is described. Simulated data are used to test themethod, and its sensitivity to noise. Heat capacity measurements from diamond areused to demonstrate the use of the method with experimental data. Comparisonbetween maximum entropy and reverse Monte Carlo results shows that the form ofthe entropy used here is correct, and that results are stable and reliable. Majorfeatures of the DOS are picked out, and acoustic and optical phonons can betreated with the same approach. The treatment set out in this paper provides acost-effective and reliable method for studies of the phonon properties of materials.