High-pressure phases of boron arsenide with potential high thermal conductivity

Zinc-blende (zb) boron arsenide (BAs) has been confirmed to have impressively high thermal conductivity. However, studies on its phase transitions under pressure have been few. Here, through a recently developed structure search method, we predicted that many polytypes with the structural features of cubic and hexagonal diamond, which are known to be unstable even up to very high pressures for carbon and boron nitride, can become stable at low pressures and might be retained to ambient conditions. Moreover, some of these BAs polytypes are calculated to have impressively high thermal conductivities at ambient conditions and the thermal conductivities for zb- and $2H$-BAs will decrease with increasing pressure, which are mainly attributed to the stronger third anharmonic interaction. The current study will open up a route to the search for high thermal conductors.