title: Structure and Failure Mechanism of the Thermoelectric CoSb3/TiCoSb Interface.
abstract: The brittle behavior and low strength of CoSb3/TiCoSb interface are serious issues concerning the engineering applications of CoSb3based or CoSb3/TiCoSb segmented thermoelectric devices. To illustrate the failure mechanism of the CoSb3/TiCoSb interface, we apply density functional theory to investigate the interfacial behavior and examine the response during tensile deformations. We find that both CoSb3(100)/TiCoSb(111) and CoSb3(100)/TiCoSb(110) are energetically favorable interfacial structures. Failure of the CoSb3/TiCoSb interface occurs in CoSb3since the structural stiffness of CoSb3is much weaker than that of TiCoSb. This failure within CoSb3can be explained through the softening of the Sb-Sb bond along with the cleavage of the Co-Sb bond in the interface. The failure mechanism of the CoSb3/TiCoSb interface is similar to that of bulk CoSb3, but the ideal tensile strength and failure strain of the CoSb3/TiCoSb interface are much lower than those of bulk CoSb3. This can be attributed to the weakened stiffness of the Co-Sb framework because of structural rearrangement near the interfacial region.
authors: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.|Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors: Guodong
authors: G
authors: Li
authors: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors: Shiqiang
authors: S
authors: Hao
authors: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors: Umut
authors: U
authors: Aydemir
authors: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors: Max
authors: M
authors: Wood
authors: Materials and Process Simulation Center, California Institute of Technology , Pasadena, California 91125, United States.
authors: William A
authors: WA
authors: Goddard
authors: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.
authors: Pengcheng
authors: P
authors: Zhai
authors: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.
authors: Qingjie
authors: Q
authors: Zhang
authors: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|ITMO University , St. Petersburg, 197101 Russia.
authors: G Jeffrey
authors: GJ
authors: Snyder
keywords: bond breakage; ideal strength; interfacial structure; tensile failure mode; thermoelectric