Dual occupations of sulfur induced band flattening and chemical bond softening in p-type S_(y)Co_(4)Sb_(12-2y)S_(2y) skutterudites  

作　　者：Jialiang Li Xiaolian Zhang Haoqin Ma Bo Duan Guodong Li Jiong Yang Hongtao Wang Houjiang Yang Ling Zhou Pengcheng Zhai 

机构地区：[1]Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics,Wuhan University of Technology,Wuhan,430070,China [2]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan,430070,China [3]Materials Genome Institute,Shanghai University,99 Shangda Road,Shanghai,200444,China

出　　处：《Journal of Materiomics》2022年第1期88-95,共8页无机材料学学报（英文）

基　　金：the financial support from the National Natural Science Foundation of China(Grant No.51772231 and 51972253);the Fundamental Research Funds for the Central Universities(WUT:2017-YB-033,2020IB001,and 2020IB013).

摘　　要：The electronegative filling in skutterudites not only broadened the scope of filling atoms,but also facilitated the preparation of p-type skutterudites.However,the introduction of a single sulfur atom in the Co_(4)Sb_(12) cannot be achieved without charge compensation through the traditional equilibrium method.In the present study,the dual occupations of S-atoms by self-charge compensation were shown as the most stable forms under high pressure,and a series of p-type S_(y)Co_(4)Sb_(12-2y)S_(2y) skutterudites was successfully prepared by high-pressure-high-temperature(HPHT)method.The electronic structures and transport properties of as-obtained materials were investigated,and the related mechanisms were explored.The results suggested that the presence of S-impurities led to flattening of the electronic band that led to a higher Seebeck coefficient.The S-doped Co_(4)Sb_(12) displayed lower elastic modulus,elastic constant,and Debye temperature,thus indicating the chemical bond softening in skutterudites.The thermal conductivities of S_(y)Co_(4)Sb_(12-2y)S_(2y) compounds reduced monotonously with the increase in Scontent.This study provides a new and promising avenue for optimizing the thermoelectric properties of p-type Co_(4)Sb_(12).

关 键 词：Electronegative filling skutterudites Self-charge compensation Band flattening Bond softening 

分 类 号：TQ17[化学工程—硅酸盐工业]