Temperature dependent elastic constants and thermodynamic properties of BAs: An ab initio investigation

We present an ab initio study of the temperature dependent elastic constants of boron arsenide, a semiconductor that exhibits ultra-high thermal conductivity and is under investigation for thermal management in electronics. We test the consistency of our predictions by computing the temperature dependent sound velocity of the longitudinal acoustic mode along the [111] direction and comparing with experiments. Furthermore, as a by-product, we present the room temperature phonon dispersions and the temperature dependent thermal expansion, isobaric heat capacity, and average Grüneisen parameter compared with the most updated experiments and previous calculations when available. Finally, we present the theoretical estimate of the temperature dependent mean square atomic displacements.