Dual-wavelength flash Raman mapping method for measuring thermal diffusivity of the suspended nanowire

作     者：HU YuDong FAN AoRan WANG HaiDong MA WeiGang ZHANG Xing HU YuDong;FAN AoRan;WANG HaiDong;MA WeiGang;ZHANG Xing

作者机构：Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2020年第63卷第5期

页      面：748-754页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0817[工学-化学工程与技术] 080501[工学-材料物理与化学] 070302[理学-分析化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51827807 and 51636002) 

主　　题：DFR mapping method thermal diffusivity nanowire dimensionless analysis 

摘      要：In this paper,we present a dual-wavelength flash Raman(DFR)mapping method for measuring the thermal diffusivity of a suspended nanowire.A heating pulse is used to heat the nanowire sample,and a probing pulse of different wavelength is used to measure the increase in *** laser absorption coefficient can be eliminated by normalization,and the thermal diffusivity of the sample can be extracted from the normalized temperature *** infinite heat conduction model is used in this method to avoid the influence of boundary thermal *** changing the position of the probing laser center,the measurement sensitivity of thermal diffusivity can be further *** position of maximum sensitivity is influenced by the thermal diffusivity of the nanowire,width of the heating pulse,radius of the heating laser spot,and characteristic length of the *** comprehensively analyze the influences of the various parameters,obtain the best measurement conditions,and attain maximum sensitivity,we propose a dimensionless physical model to analyze the heat conduction of the suspended *** on the analysis of the best dimensionless parameters,the corresponding appropriate measurement conditions can be *** analysis shows that when the radius of the heating laser spot is 1%of the length of the nanowire,the sensitivity of the DFR mapping method can be more than four times that of the concentric DFR method for measuring the thermal diffusivity of the nanowire.