Ma Dengke, Zhang Lifa
NNU-SULI Thermal Energy Research Center (NSTER) and Center for Quantum Transport and Thermal Energy Science (CQTES), School of Physics and Technology, Nanjing Normal University, Nanjing, 210023, People's Republic of China.
J Phys Condens Matter. 2020 Jul 23;32(42). doi: 10.1088/1361-648X/aba014.
Facilitating interfacial thermal transport is highly desirable for various engineering applications, such as improving heat dissipation in microelectronics and efficiency of electrothermal heating element. Here, the interface thermal conductances (ITCs) of CrNi/MgO and CrNi/AlOinterfaces are studied through the non-equilibrium molecular dynamics simulation. It is found that the two ITCs can be hugely enhanced by 3 and 2.4 times, respectively, with the introduction of Cu nano-interlayer of a thickness larger than 7.2 Å. The enhanced ratio is robust and shows weak dependence on temperature. Further vibrational spectral analysis and phonon transmission function reveal that the enhancement in ITC mainly originates from the boosting of inelastic phonon scattering, which is generally considered to contribute a small proportion to ITC. Here, the inelastic scattering contributes as high as 63% to the ITC of CrNi/Cu/MgO interface at 300 K. The findings provide an effective strategy to enhance ITC at a wide temperature range and advance our understanding of inelastic scattering in interfacial phonon transport.
促进界面热传输对于各种工程应用非常重要，例如改善微电子中的散热和电热加热元件的效率。在此，通过非平衡分子动力学模拟研究了CrNi/MgO和CrNi/AlO界面的界面热导率（ITC）。研究发现，通过引入厚度大于7.2 Å的Cu纳米中间层，两种ITC分别可大幅提高3倍和2.4倍。增强比例稳定，且对温度的依赖性较弱。进一步的振动光谱分析和声子传输函数表明，ITC的增强主要源于非弹性声子散射的增强，而通常认为非弹性声子散射对ITC的贡献较小。在此，在300 K时，非弹性散射对CrNi/Cu/MgO界面的ITC贡献高达63%。这些发现提供了一种在宽温度范围内增强ITC的有效策略，并推进了我们对界面声子传输中非弹性散射的理解。
