High-pressure physical properties for P6m2-ReB3

Abstract:

In this paper, three crystal structures of ReB3, P6m2, P63/mmc, P3m1, and their structural poroperties, are calculated by using pseudopotential plane-wave method. It is found that the P6m2-ReB3 is the ground-state phase of ReB3. In particular, the elastic properties such as, elastic constants, elastic anisotropy, aggregate moduli and wave velocities of P6m2-ReB3 under high pressure are investigated systematically for the first time. The toughness and brittleness are also predicted for the P6m2-ReB3 structure. In addition, dependences of the Debye temperature, normalized volume, bulk modulus, thermal expansion coefficient, and heat capacity on pressure or temperature for the P6m2-ReB3 structure are analyzed through the quasi-harmonic Debye model.