Temperature Dependent Ultrasonic Characterization of Wurtzite Boron Nitride

The present study encloses the evaluation of second order elastic constants of wurtzite boron nitride (w-BN) in temperature range 300K-1800K using the many body interaction potential model approach. Orientation and temperature dependent ultrasonic velocity, thermal relaxation time and other related thermo-physical parameters (Debye average velocity, Debye temperature,specific heat, thermal energy density and thermal conductivity) are also calculated using evaluated second order elastic constants and other known parameters of w-BN. It is found that thermal relaxation time is least for the wave propagation along 55° from the unique axis of crystal at each temperature. The orientation dependent thermal relaxation time of w-BN is predominantly affected by the Debye average velocity while the temperature dependent thermal relaxation time is governed by thermal conductivity. The calculated elastic and ultrasonic properties of w-BN are compared with the properties of other wurtzite structured materials for the complete analysis and characterization of material.