DIFFERENTIAL AND TOTAL PHONON FREQUENCY DISTRIBUTION FUNCTIONS FROM THE CORRESPONDING MEASURED TEMPERATURE DEPENDENT MEAN SQUARE DISPLACEMENTS IN AN ANISOTROPIC CRYSTAL USING UNFOLDING TECHNIQUE

Abstract

It is shown, for the first time, that phonon frequency distribution function (FDF) can be successfully extracted from the measured temperature dependent mean square displacement (MSD) of a particle in a condensed system using unfolding technique. In particular, the observed MSD of a Zinc atom in the basal plane, along the z direction and the total have been unfolded to obtain corresponding phonon FDF which yield much better values of the temperature dependent MSD than the trial FDF. The method can be fruitfully utilized to obtain FDF of elastic vibrations both for ordered and disordered solids from the readily available experimental MSD.