Kundu Ashis, Yang Xiaolong, Ma Jinlong, Feng Tianli, Carrete Jesús, Ruan Xiulin, Madsen Georg K H, Li Wu
Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Phys Rev Lett. 2021 Mar 19;126(11):115901. doi: 10.1103/PhysRevLett.126.115901.
Extracting long-lasting performance from electronic devices and improving their reliability through effective heat management requires good thermal conductors. Taking both three- and four-phonon scattering as well as electron-phonon and isotope scattering into account, we predict that semimetallic θ-phase tantalum nitride (θ-TaN) has an ultrahigh thermal conductivity (κ), of 995 and 820 W m^{-1} K^{-1} at room temperature along the a and c axes, respectively. Phonons are found to be the main heat carriers, and the high κ hinges on a particular combination of factors: weak electron-phonon scattering, low isotopic mass disorder, and a large frequency gap between acoustic and optical phonon modes that, together with acoustic bunching, impedes three-phonon processes. On the other hand, four-phonon scattering is found to be significant. This study provides new insight into heat conduction in semimetallic solids and extends the search for high-κ materials into the realms of semimetals and noncubic crystal structures.
要从电子设备中获得持久性能并通过有效的热管理提高其可靠性，需要良好的热导体。综合考虑三声子和四声子散射以及电子 - 声子和同位素散射，我们预测半金属θ相氮化钽（θ-TaN）具有超高的热导率（κ），在室温下沿a轴和c轴分别为995和820 W m⁻¹ K⁻¹。声子被发现是主要的热载体，高κ取决于多种因素的特定组合：弱电子 - 声子散射、低同位素质量无序以及声学和光学声子模式之间的大频率间隙，这与声学聚束一起阻碍了三声子过程。另一方面，发现四声子散射很显著。这项研究为半金属固体中的热传导提供了新的见解，并将对高κ材料的探索扩展到半金属和非立方晶体结构领域。
