Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA.
Nat Commun. 2019 Feb 19;10(1):827. doi: 10.1038/s41467-019-08713-0.
Recent experiments demonstrate that boron arsenide (BAs) is a showcase material to study the role of higher-order four-phonon interactions in affecting heat conduction in semiconductors. Here we use first-principles calculations to identify a phenomenon in BAs and a related material - boron antimonide, that has never been predicted or experimentally observed for any other material: competing responses of three-phonon and four-phonon interactions to pressure rise cause a non-monotonic pressure dependence of thermal conductivity, κ, which first increases similar to most materials and then decreases. The resulting peak in κ shows a strong temperature dependence from rapid strengthening of four-phonon interactions relative to three-phonon processes with temperature. Our results reveal pressure as a knob to tune the interplay between the competing phonon scattering mechanisms in BAs and similar compounds, and provide clear experimental guidelines for observation in a readily accessible measurement regime.
最近的实验表明，砷化硼（BAs）是研究高阶四声子相互作用在影响半导体热导中作用的典型材料。在这里，我们使用第一性原理计算来确定砷化硼和一种相关材料 - 锑化硼中从未被预测或实验观察到的现象：三声子和四声子相互作用对压力升高的竞争响应导致热导率κ随压力的非单调依赖性，其最初类似于大多数材料，然后降低。κ的这种峰值表现出与三声子过程相比，四声子相互作用随温度迅速增强的强烈温度依赖性。我们的结果表明，压力是调节砷化硼和类似化合物中竞争声子散射机制相互作用的一个旋钮，并为在易于测量的实验范围内观察到这一现象提供了明确的实验指导。
