Experimental study on the influences of grain boundary scattering on the charge and heat transport in gold and platinum nanofilms
Experimental study on the influences of grain boundary scattering on the charge and heat transport in gold and platinum nanofilms
复制标题
晶界散射对金铂纳米薄膜电荷和热传输影响的实验研究
DOI：
10.1007/s00231-011-0825-5
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发表时间：
2011-08-01
影响因子：
2.2
通讯作者：
Takahashi, Koji
中科院分区：
文献类型：
--
作者：
Wang, Hai-Dong;Liu, Jin-Hui;Takahashi, Koji
用直流加热法在60 ~ 300 K温度范围内同时测量了多晶金和铂纳米薄膜的电导率和热导率。测得的电导率和热导率从相应的体积值大大降低。研究发现，随着温度的降低，还原率增大。与体值的偏差是由于晶界散射的影响。此外，实验结果表明，晶界散射效应对电荷输运的影响大于热输运。因此，洛伦兹数是体材料的几倍，导致违反了Wiedemann-Franz定律。根据Mayadas-Shatzkes理论和Matthiessen规则，得到了晶界处的反射系数R（铂为0.86，金为0.42），与前人的实验结果符合得很好。
The electrical and thermal conductivities of polycrystalline gold and platinum nanofilms have been measured simultaneously using a direct current heating method from 60 to 300 K. The measured electrical and thermal conductivities are greatly decreased from the corresponding bulk values. And it is found that the reduction increases as the temperature decreases. The deviation from the bulk value is due to the effect of grain boundary scattering. Furthermore, the experimental results indicate that the grain boundary scattering effect imposes greater influence to the charge transport than to the heat transport. Consequentially, the Lorentz number is several times larger than that of bulk materials, leading to the violation of the Wiedemann–Franz law. The reflection coefficientR(0.86 in platinum, 0.42 in gold) at grain boundaries is obtained based on the Mayadas-Shatzkes theory and Matthiessen’s rule, which agrees well with the previous experiments.