Unveiling the thermal transport properties of various one-dimensional(1D)or quasi-1D materials like nanowires,nanotubes,and nanorods is of great importance both theoretically and experimentally.The dimension or size d...Unveiling the thermal transport properties of various one-dimensional(1D)or quasi-1D materials like nanowires,nanotubes,and nanorods is of great importance both theoretically and experimentally.The dimension or size dependence of thermal conductivity is crucial in understanding the phonon-phonon interaction in the low-dimensional systems.In this paper,we experimentally investigate the size-dependent thermal conductivity of individual single crystallineα-Fe2O3 nanowires collaborating the suspended thermal bridge method and the focused electron-beam self-heating technique,with the sample diameter(d)ranging from 180 nm to 661 nm and length(L)changing from 4.84μm to 20.73μm.An empirical relationship for diameter-/length-dependent thermal conductivity is obtained,which shows an approximately linear dependence on the aspect ratio(L/(1+Cd))at T=300 K,where C is a fitting parameter.This is related to the boundary scattering and diameter effect ofα-Fe2O3 nanowires although rigorous calculations are needed to confirm the result.展开更多
基金the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2020B010190004)the National Natural Science Foundation of China(Grant Nos.11674245,11775158,11890703,and 11935010)+1 种基金the Open Fund of Zhejiang Provincial Key Laboratory of Quantum Technology and Device,China(Grant No.20190301)the Shanghai Committee of Science and Technology in China(Grant Nos.17142202100,17ZR1447900,and 17ZR1432600)。
文摘Unveiling the thermal transport properties of various one-dimensional(1D)or quasi-1D materials like nanowires,nanotubes,and nanorods is of great importance both theoretically and experimentally.The dimension or size dependence of thermal conductivity is crucial in understanding the phonon-phonon interaction in the low-dimensional systems.In this paper,we experimentally investigate the size-dependent thermal conductivity of individual single crystallineα-Fe2O3 nanowires collaborating the suspended thermal bridge method and the focused electron-beam self-heating technique,with the sample diameter(d)ranging from 180 nm to 661 nm and length(L)changing from 4.84μm to 20.73μm.An empirical relationship for diameter-/length-dependent thermal conductivity is obtained,which shows an approximately linear dependence on the aspect ratio(L/(1+Cd))at T=300 K,where C is a fitting parameter.This is related to the boundary scattering and diameter effect ofα-Fe2O3 nanowires although rigorous calculations are needed to confirm the result.
