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金属纳米薄膜作为一种典型的纳米材料,已广泛应用于信息技术领域。研究表明,随着金属薄膜特征尺寸的减小,金属薄膜体现出与常规不同的热输运特性。本文采用飞秒激光泵浦-探测实验方法,结合抛物两步模型和修正的抛物两步模型,对铝纳米薄膜热导率进行研究。结果表明,考虑了声子热导率修正的抛物两步模型比抛物两步模型更能准确描述热反射信号。拟合得到铝膜热导率分别为98 W·m~(-1)·K~(-1)和94 W.m~(-1)·K~(-1),小于铝的体材料热导率,铝纳米薄膜热导率具有尺度效应,同时拟合得到声子热导率为2.8 W·m~(-1)·K~(-1),提出一种利用飞秒激光泵浦-探测测量声子热导率的方法。
As a typical nano-material, metal nano-film has been widely used in information technology. The research shows that with the reduction of the feature size of the metal thin film, the metal thin film shows different heat transport characteristics from conventional ones. In this paper, the femtosecond laser pump-detection experiment method, combined with the parabolic two-step model and the modified parabolic two-step model, the thermal conductivity of aluminum nanofilms were studied. The results show that the parabolic two-step model considering the phonon thermal conductivity correction can describe the thermal reflection signal more accurately than the parabolic two-step model. The thermal conductivities of bulk materials with aluminum thermal conductivities of 98 W · m -1 K -1 and 94 Wm -1 K -1 were obtained. , The thermal conductivity of aluminum nanofilms has scale effect, and the phonon thermal conductivity is fitted to 2.8 W · m -1 K -1. A new method using femtosecond laser pump-probe Method of phonon thermal conductivity.