Lattice thermal conductivity of transition metal carbides: Evidence of a strong electron-phonon interaction above room temperature

Abstract Strong electron-phonon interaction, can not only control charge carrier mobility, but also impact heat transport by reducing lattice thermal conductivity. In this work, we reveal by experiments a strong electron-phonon interaction in group IV and V transition metal carbides, which results in anomalous weak temperature dependence of lattice thermal conductivity from 300 K up to 773 K. This contrasts with the common belief that electron-phonon interaction would be only important for lattice heat transport at very low temperatures. The other important finding is that strong electron-phonon interaction can notably suppress lattice thermal transport and its temperature dependence provided that free charge carrier density is large enough, whereas Fermi surface nesting may not be necessary. This work provides new perspective on electron-phonon interaction and its consequence on lattice thermal conduction in solids, and it suggests a new avenue to modulate heat transfer above room temperature.