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).
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).
作者简介
Jialiang Li received his B.S.degree from China Three Gorges University in 2008 and M.S.degree from WUT in 2016.He is pursuing his Ph.D.at WUT,China.His research interest mainly focus on thermoelectric bulk materials;Corresponding author:Bo Duan,E-mail addresses:duanboabc@126.com, is an associate professor of Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics at WUT.He received his Ph.D.degree from WUT in 2012.His research interests include synthesis and characterization of thermoelectric materials and investigation of their mechanical behavior;Corresponding author:Pengcheng Zhai,E-mail addresses:pczhai@126.com.Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics,Wuhan University of Technology,Wuhan,430070,China, is a professor of the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing at WUT.He received his Ph.D.degree from WUT in 1998.His current research interests include theoretical calculations of transport properties and mechanical failure of thermoelectric materials,theoretical modeling of heat transport properties of thermoelectric modules,thermoelectric bulk materials and the related application technology.
