Tantalum metal nitride in the θ-phase has a thermal conductivity three times that of copper.[1] This material is described in a peer-reviewed study in the journal Science, Volume 391, Number 6786, Pages 707-711, February 2026. The main finding is the exceptionally high thermal conductivity of the θ-phase of tantalum nitride compared to copper, the standard metal with high thermal conductivity. The thermal conductivity of metals depends on the free electrons that transfer heat. The study highlights the metallic nature of this nitride.