Ultrahigh Thermal Conductivity of θ-Phase Tantalum Nitride

Extracting long-lasting performance from electronic devices and improving their reliability through effective heat management requires good thermal conductors. Taking both three- and four-phonon scattering as well as electron-phonon and isotope scattering into account, we predict that semimetallic theta-phase tantalum nitride (theta-TaN) has an ultrahigh thermal conductivity (kappa), of 995 and 820 W m(-1) K-1 at room temperature along the a and c axes, respectively. Phonons are found to be the main heat carriers, and the high kappa hinges on a particular combination of factors: weak electron-phonon scattering, low isotopic mass disorder, and a large frequency gap between acoustic and optical phonon modes that, together with acoustic bunching, impedes three-phonon processes. On the other hand, four-phonon scattering is found to be significant. This study provides new insight into heat conduction in semimetallic solids and extends the search for high-kappa materials into the realms of semimetals and noncuhic crystal structures.

Automated summary

This study provides new insights into heat conduction in semimetallic solids, revealing that semimetallic theta-phase tantalum nitride (theta-TaN) has an ultrahigh thermal conductivity. Phonons are found to be the main heat carriers, and the high thermal conductivity relies on a combination of factors.