Elastic and Acoustic Properties of Hexagonal MnB2, TcB2 and ReB2 Compounds

The paper presents a comprehensive computation of second-and third-order elastic constants using LennardJones potential and then velocities and attenuation of acoustics waves along unique direction in hexagonal structured MnB2, TcB2 and ReB2 compounds. The comparison of these computed results has been made with available theoretical and experiment results. The orientation dependent acoustic velocity has been also evaluated to study the anisotropic behaviour of these compounds. The inconsistent behaviour of angle-dependent velocities is associated to the action of second order elastic constants. The average sound velocity is a direct consequence of Debye temperature, specific heat and thermal energy density of these compounds. The mechanical properties of MnB2 are better than those of ReB2, because MnB2 has high ultrasonic velocities and low attenuation. Obtained results, together with other well known physical properties, may expand future prospects for the applications and study of these materials.