Temperature Dependent Elastic and Ultrasonic Properties of Silver Halide Crystals

The present study deals with the computation of higher order elastic constants and ultrasonic properties of AgCl and AgBr in temperature range 0-300K. The elastic constants are estimated using Coulomb and Born-Mayer potential with two basic parameters i.e., nearest neighbour distance and hardness parameter. The ultrasonic velocity for longitudinal and shear waves along <100>, <110> and <111> orientations for temperature range 100-300K have been evaluated with second order elastic constant and density of the silver halides. The Debye average velocity, Debye temperature, bulk modulus, Breazeale's non-linearity parameter, Young's modulus and Poisson's ratio are also computed. The fracture/toughness (B/G) ratio is less than 1.75 which shows that the compounds are brittle in nature at room temperature. The materials fulfil the Born criterion of stability. AgCl is stiffer in comparison to AgBr as it has higher values of elastic constants and ultrasonic velocity.