Anharmonic Properties of MnO, MnSe and MnS

Elastic properties of a divalent compound are important because they relate to the various fundamental solid state phenomena such as inter—atomic potentials, equation of state and phonon spectra. If the values of second order elastic constants and density at a particular temperature are known for any substance, one may obtain ultrasonic velocities for longitudinal and shear waves which give an important information about its anharmonic properties. An effort has been made for obtaining higher order elastic constants starting from basic parameters viz. nearest neighbor distance, hardness parameter and using Coulomb and Börn‐Mayer potentials. The higher order elastic constants, first order pressure derivatives of second and third order elastic constants, second order pressure derivatives of second order elastic constants and partial contractions for Manganese Compounds are evaluated from 100K to up their melting point using this theory.