Different effects of grain boundary scattering on charge and heat transport in polycrystalline platinum and gold nanofilms

作     者：马维刚 王海东 张兴 Takahashi Koji 

作者机构：Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationDepartment of Engineering MechanicsTsinghua University Graduate School of EngineeringKyushu University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2009年第18卷第5期

页      面：2035-2040页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos 50676046 and 50730006) 

主　　题：polycrystalline nanofilm grain boundary scattering thermal and electrical conductivities Wiedemann-Franz law 

摘      要：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.