Structural, electronic, elastic and vibrational properties of two dimensional graphene-like BN under high pressure

Abstract

The structural, electronic, elastic and vibrational properties of boron nitride (BN) were analyzed using ab initio computational methods based on density functional theory. The exchange-correlation energy functional was evaluated using the local density approximation (LDA) under pressure. BN crystallizes in hexagonal structure (h-BN) with symmetry P63/mmc. The structural transform was obtained at the BN from h-BN transformed into wurtzite (w-BN) with symmetry P63mc at 12.5 GPa. During this phase transformation, intermediate states with space group P3¯m1 and P3m1were observed. Besides, the electronic properties for the obtained stable phases of BN were calculated. Both structures have a semiconductor character with a direct band gap. We also made elastic and phonon calculations to understand the mechanical and dynamically stability of the obtained phases of BN. BN is stable in both phases. As a result of the literature searches, the obtained intermediate states were first predicted in this study. Thus, we believe that this study will guide the experimental studies to be conducted. © 2019 Elsevier Ltd