Phase diagram and thermal conductivity of TaN from first principles

Thermal management is essential to optimizing today's high-power electronic devices. As heat dissipation becomes increasingly important as a means of thermal management, there is growin interest in designing novel materials with high thermal conductivity. Recently, several theoretical studies confirmed that the lattice thermal conductivity of semimetallic tantalum nitride in the θ-phase (θ-TaN) could theoretically be as high as 1000Wm^-1K^-1, and could increase by up to 60% upon applying pressure. In this work, we continue to investigate thermal conductivity in the TaN system by means of first-principles Boltzmann transport calculations. In particular, we investigate the thermodynamic phase diagram of the θ-, δ- and ε-TaN polymorphs within the quasi-harmonic approximation, and we compute thermal conductivity under various conditions of temperature and pressure. We also investigate how electron-phonon interactions change across the phae diagrams, and their impact on thermal conductivity.