Pressure Dependent Lattice Specific Heat and Mode Grüneisen Parameters for Group III Nitrides

Abstract

The pressure dependent lattice specific heat and mode Grüneisen parameters for III-V nitrides have been calculated using a lattice dynamical model namely the rigid ion model which consists of a usual long range and short range potential. The Murnaghan’s equation of state is adopted for relating the volume dependence with pressure. The non linear least square fitting procedures to obtain the model parameters have been used. The results obtained using the present model calculation on mode Grüneisen parameters and specific are compared with existing experimental data and found in good agreement. There is a increase in in specific heat with pressure. The mode Grüneisen parameters show that the TA phonon mode is responsible for phase transition.