A UCLA-led, multi-institution research team has discovered a metallic material with the highest thermal conductivity measured among metals, challenging long-standing assumptions about the limits of heat transport in metallic materials.

Published this week in Science, the study is led by Yongjie Hu, a professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering. The team reported that metallic theta-phase tantalum nitride conducts heat nearly three times more efficiently than copper or silver, the best conventional heat-conducting metals.

Thermal conductivity describes how efficiently a material can carry heat. Materials with high thermal conductivity are essential for removing localized hot spots in electronic devices, where overheating limits performance, reliability and energy efficiency. Copper currently dominates the global heat-sink market, accounting for roughly 30% of commercial thermal-management materials, with a thermal conductivity of about 400 watts per meter-kelvin.