Extremely low lattice thermal conductivity in light-element solid materials  

作　　者：Ni Ma Lu Liu Runhua Wu Juping Xu Wen Yin Kai Li Wei Bai Jiong Yang Chong Xiao Yi Xie 

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China [2]Materials Genome Institute,Shanghai University,Shanghai 200444,China [3]Spallation Neutron Source Science Center,Dongguan 523803,China [4]Zhejiang Laboratory,Hangzhou 311100,China

出　　处：《National Science Review》2025年第1期171-178,共8页国家科学评论(英文版)

基　　金：supported by the National Key R&D Program of China(2022YFA1203600);the National Natural Science Foundation of China(T2325021,22109153 and 22321001);the CAS Project for Young Scientists in Basic Research(YSBR-070);the University Synergy Innovation Program of Anhui Province(GXXT-2021-022 and GXXT-2022-008);the National Synchrotron Radiation Laboratory Joint Funds of the University of Science and Technology of China(KY2060000241).

摘　　要：Lattice thermal conductivity(κl)is of great importance in basic sciences and in energy conversion applications.However,low-κl crystalline materials have only been obtained from heavy elements,which typically exhibit poor stability and possible toxicity.Thus,low-κl materials composed of light elements should be explored.Herein,light elements with hierarchical structures in a simple square-net lattice as well as a small discrepancy in atomic mass and radius exhibit lowκl.The hierarchical structure exhibits various chemical bonds and asymmetric geometry of building units,resulting in flat phonon branches and strong phonon-phonon interactions similar to those observed in heavy-element materials.These phenomena generate a large phonon anharmonicity,which is the prerequisite for achieving extremely lowκl.For example,KCu4_(S)e_(3)exhibits an extremely lowκl of 0.12 W/(m·K)at 573 K,which is lower than that of most heavy-element materials.These findings can reshape our fundamental understanding of thermal transport properties of materials and advance the design of low-κl solids comprising light elements.

关 键 词：low lattice thermal conductivity light-element materials square-net lattice 

分 类 号：TB34[一般工业技术—材料科学与工程]