2026-04-09 アルゴンヌ国立研究所（ANL）
Electron microscope image (left) and X-ray diffraction image (right) of a single crystal of theta-phase tantalum nitride. (Images courtesy of Yongjie Hu/UCLA.)
＜関連情報＞
- https://www.anl.gov/article/researchers-discover-recordsetting-heatconducting-material
- https://www.science.org/doi/full/10.1126/science.aeb1142
金属θ相窒化タンタルの熱伝導率は銅の3倍である Metallic θ-phase tantalum nitride has a thermal conductivity triple that of copper
Suixuan Li, Chuanjin Su, Zihao Qin, Ahmet Alatas, […] , and Yongjie Hu
Science Published:15 Jan 2026
DOI:https://doi.org/10.1126/science.aeb1142
Editor’s summary
Single crystals of the θ-phase of tantalum nitride have an ultrahigh thermal conductivity, consistent with previous theoretical predictions. Li et al. used time-domain thermoreflectance to show that their samples had a thermal conductivity about three times greater than that of copper. Inelastic x-ray scattering revealed that phonon-phonon scattering, which reduces thermal conductivity, was suppressed. —Phil Szuromi
Abstract
Efficient heat dissipation is fundamentally limited by intrinsic scattering mechanisms that cap the thermal conductivity of metallic materials such as copper to ~400 watts per meter-kelvin. Here we report the experimental realization of single-crystalline θ-phase tantalum nitride (θ-TaN), a metastable transition metal nitride predicted to overcome this limitation. We measured a room-temperature thermal conductivity of ~1100 watts per meter-kelvin, nearly three times that of copper. Synchrotron-based inelastic x-ray scattering revealed a distinctive phonon band structure with a large acoustic-optical gap and phonon bunching, which suppress phonon-phonon scattering. Ultrafast optical spectroscopy confirmed exceptionally weak electron-phonon coupling and validated first-principles calculations. These findings redefine the thermal transport limits of metallic materials and open new opportunities for advancing thermal management in electronics and power systems.
