Different effects of grain boundary scattering on chargeand heat transport in polycrystalline platinum and goldnanofilms |
| |
| Authors: | Ma Wei-Gang Wang Hai-Dong Zhang Xing and TakahashiKoji |
| |
| Affiliation: | Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan; Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China |
| |
| Abstract: | The in-plane electrical and thermal conductivities of several
polycrystalline platinum and gold nanofilms with different
thicknesses are measured in a temperature range between the boiling
point of liquid nitrogen (77K) and room temperature by using the
direct current heating method. The result shows that both the
electrical and thermal conductivities of the nanofilms reduce
greatly compared with their corresponding bulk values. However, the
electrical conductivity drop is considerably greater than the
thermal conductivity drop, which indicates that the influence of the
internal grain boundary on heat transport is different from that of
charge transport, hence leading to the violation of the
Wiedemann--Franz law. We build an electron relaxation model based on
Matthiessen's rule to analyse the thermal conductivity and
employ the Mayadas & Shatzkes theory to analyse the electrical
conductivity. Moreover, a modified Wiedemann--Franz law is provided
in this paper, the obtained results from which are in good agreement
with the experimental data. |
| |
| Keywords: | polycrystalline nanofilm grain
boundary scattering thermal and electrical conductivities Wiedemann--Franz law |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《中国物理 B》浏览原始摘要信息 |
|
点击此处可从《中国物理 B》下载免费的PDF全文 |
|
