Morales C, Flores E, Bodega J, Leardini F, Ferrer I J, Ares J R, Sánchez C
Departamento Física Aplicada, Universidad Autónoma de Madrid, Madrid 28049, Spain.
Departamento Física de Materiales, Universidad Autónoma de Madrid, Madrid 28049, Spain.
Rev Sci Instrum. 2016 Aug;87(8):084902. doi: 10.1063/1.4960331.
The electrical van der Pauw's method has recently been extended to measure the thermal conductivity of different elements and compounds. This technique provides an easy way to determine the sample in-plane thermal conductivity by avoiding the influence of the thermal contact resistances. However, the reported calculated error values appear to be underestimated when dealing with the materials with low thermal conductivity (<5 W/Km) at room temperature. The causes of this underestimation are investigated in this communication and it has been found that they are due to the drastic influence of conduction heat losses through the thermo-resistance wires as well as the resulting modification of the sample temperature map. Both phenomena lead to experimental values of the sample thermal conductivity, which are systematically higher than the tabulated ones. The magnitude of this systematic error is ∼100% dealing with the samples of macroscopic dimensions, and low thermal conductivity indicated that the obtained accurate measurements can be quite challenging.
最近，电范德堡方法已被扩展用于测量不同元素和化合物的热导率。该技术通过避免热接触电阻的影响，提供了一种测定样品面内热导率的简便方法。然而，在处理室温下热导率较低（<5 W/Km）的材料时，报告的计算误差值似乎被低估了。本通讯对这种低估的原因进行了研究，发现这是由于通过热阻丝的传导热损失的剧烈影响以及样品温度分布的相应改变所致。这两种现象导致样品热导率的实验值系统地高于表格中的值。对于宏观尺寸且热导率低的样品，这种系统误差的大小约为100%，这表明获得准确的测量结果可能颇具挑战性。
