A groundbreaking discovery by a UCLA-led research team has identified a metallic material with the highest thermal conductivity ever measured in metals, challenging long-standing assumptions about heat transport limits. This pivotal study, led by Professor Yongjie Hu of the UCLA Samueli School of Engineering, has been published in the prestigious journal Science.
The team reported that metallic theta-phase tantalum nitride conducts heat nearly three times more efficiently than copper or silver, the metals traditionally known for their superior heat conduction. This discovery sets a new benchmark for metallic materials, with tantalum nitride exhibiting an ultrahigh thermal conductivity of approximately 1,100 watts per meter-kelvin (W/mK).
Revolutionizing Thermal Management
Thermal conductivity is a measure of how effectively a material can transport heat. High thermal conductivity materials are crucial for dissipating localized hotspots in electronic devices, where overheating can hinder performance, reliability, and energy efficiency. Currently, copper dominates the global heat-sink market, representing about 30% of commercial thermal-management materials with a thermal conductivity of around 400 W/mK.
Professor Hu, also a member of the California NanoSystems Institute at UCLA, emphasized the significance of this discovery. “As AI technologies advance rapidly, heat-dissipation demands are pushing conventional metals like copper to their performance limits. Our research shows that theta-phase tantalum nitride could be a fundamentally new and superior alternative for achieving higher thermal conductivity and may help guide the design of next-generation thermal materials,” he stated.
Breaking Historical Boundaries
For over a century, copper and silver have been considered the pinnacle of thermal conductivity among metals. In metallic materials, heat is transported by free-moving electrons and atomic vibrations known as phonons. Historically, strong interactions between electrons and phonons, as well as phonon-phonon interactions, have limited the efficiency of heat flow in metals. The UCLA team’s discovery demonstrates that these long-standing benchmarks can indeed be surpassed.
Theoretical modeling suggested that theta-phase tantalum nitride’s unique atomic structure, with tantalum atoms interspersed with nitrogen atoms in a hexagonal pattern, could facilitate unusually efficient heat transport. The team confirmed the material’s performance using advanced techniques such as synchrotron-based X-ray scattering and ultrafast optical spectroscopy, which revealed extremely weak electron–phonon interactions.
Implications for Technology
Beyond microelectronics and AI hardware, this discovery could significantly impact a wide range of technologies increasingly constrained by heat, including data centers, aerospace systems, and emerging quantum platforms. The potential applications of this material could redefine thermal management strategies across various industries.
Professor Hu is no stranger to pioneering discoveries in electronics thermal management. In 2018, he led the experimental discovery of boron arsenide, another high-thermal-conductivity semiconductor material. His group has since demonstrated high-performance thermal interfaces and gallium nitride devices integrating boron arsenide for cooling, showcasing the material’s promise for next-generation semiconductor technologies.
Collaborative Efforts and Future Directions
The study’s co-lead authors, Suixuan Li, Chuanjin Su, and Zihao Qin, are all graduate students from Hu’s H-Lab at UCLA Samueli. The research also involved collaborators from the U.S. Department of Energy’s Argonne National Laboratory, Lawrence Berkeley National Laboratory, Tohoku University in Japan, and the UC Irvine Materials Research Institute.
The research was funded in part by the U.S. Department of Energy and the National Science Foundation, with computational support provided by the UCLA Institute for Digital Research and Education’s Research Technology Group and Bridges-2 at the Pittsburgh Supercomputing Center.
As the world continues to grapple with the challenges of efficient thermal management in rapidly advancing technological fields, the discovery of theta-phase tantalum nitride offers a promising new direction. The implications of this research could lead to significant advancements in the design and development of future thermal materials, potentially reshaping the landscape of electronic and industrial applications.
