Liu Jinhui, Liu Hao, Ma Weigang, Zhang Xing
MIIT Key Laboratory of Thermal Control of Electronic Equipment, School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
Rev Sci Instrum. 2019 Apr;90(4):044901. doi: 10.1063/1.5080728.
A non-contact T-type Raman method was presented for characterizing the thermophysical properties of individual micro-/nanowires, using a suspended sample-attached T-type sensor. The sensor wire's thermal diffusivity was determined by the laser flash Raman spectroscopy method, which directly extracts the thermal diffusivity (α) by comparing the square pulse and continuous laser heating induced temperature rise. The test wire's thermal conductivity (λ) can be extracted by comparing the laser spot heating the sensor wire induced local temperature rise before and after the attachment of the test wire. This non-contact T-type method was verified by comparing the measured thermal conductivity of an individual 25 µm diameter Pt wire with the standard value and then applied in the thermal transport property characterization of an individual 17 µm diameter carbon fiber. Experimental results indicated that the thermal conductivity first increases and then decreases in the temperature range from 215 K to 470 K. In principle, the presented non-contact method is applicable to characterize any individual micro-/nanowires, even those without Raman spectra.
提出了一种非接触式T型拉曼方法，用于表征单个微/纳米线的热物理性质，该方法使用了附着有悬浮样品的T型传感器。传感器线的热扩散率通过激光闪光拉曼光谱法测定，该方法通过比较方脉冲和连续激光加热引起的温度升高直接提取热扩散率（α）。通过比较在测试线附着前后激光光斑加热传感器线引起的局部温度升高，可以提取测试线的热导率（λ）。通过将测量的直径为25 µm的单根铂丝的热导率与标准值进行比较，验证了这种非接触式T型方法，然后将其应用于直径为17 µm的单根碳纤维的热输运性质表征。实验结果表明，在215 K至470 K的温度范围内，热导率先增大后减小。原则上，所提出的非接触方法适用于表征任何单个微/纳米线，甚至那些没有拉曼光谱的微/纳米线。
