Enhanced thermoelectric performance of Sb-doped Mg_(2)Si_(0.4)Sn_(0.6)via doping,alloying and nanoprecipitation  

作　　者：Binhao Wang Haidong Zhao Jianghua Li Bin Zhang Dan Wang Chen Chen Aihua Song Wentao Hu Dongli Yu Bo Xu Yongjun Tian 

机构地区：[1]Center for High Pressure Science,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao,Hebei,066004,China [2]Shaanxi University of Technology,Hanzhong,Shaanxi,723000,China

出　　处：《Journal of Materiomics》2024年第2期285-292,共8页无机材料学学报（英文）

基　　金：supported by the National Key R&D Program of China(2018YFA0305900);the Natural Science Foundation of Hebei Province of China(E2022203109);the National Natural Science Foundation of China(51901120,52288102,and 52090020);the Shaanxi Province Natural Science Basic Research Program for Youth Researchers(2020JQ-871).

摘　　要：With the advantages of eco-friendliness,low cost,and low density,Mg_(2)(Si,Sn)solid solutions are promising candidates for thermoelectric applications.In this work,Sb-doped Mg_(2)Si_(0.4)Sn_(0.6)bulks were prepared with a combined method of solid-state reaction and high pressure synthesis,followed by spark plasma sintering.Our investigations show that Sb doping optimizes the carrier concentration,while Si/Sn alloying effectively suppresses the lattice thermal conductivity and induces a convergence of the two lowest-lying conduction bands.Additionally,numerous coherent Sn-rich nanoprecipitates are formed within micron-sized grains.All these factors contribute synergistically to improving the thermoelectric properties of Mg_(2)Si_(0.4)Sn_(0.6).The optimal Mg_(2)(Si_(0.4)Sn_(0.6))_(0.985)Sb_(0.015)exhibits a power factor higher than 4000 mW·m^(-1)·K^(-2)and a lattice thermal conductivity less than 0.8 W·m^(-1)·K^(-1)at temperatures higher than 600 K,leading to the highest ZT of 1.61 at 823 K.Current work demonstrates an effective approach to enhancing the thermoelectric performance of n-type Mg_(2)X solid solutions through doping,alloying,and microstructure modification.

关 键 词：Magnesium silicide High pressure synthesis Alloy scattering Band convergence 

分 类 号：TG14[一般工业技术—材料科学与工程]