title: Concerted Rattling in CsAg5 Te3 Leading to Ultralow Thermal Conductivity and High Thermoelectric Performance.
abstract: Thermoelectric (TE) materials convert heat energy directly into electricity, and introducing new materials with high conversion efficiency is a great challenge because of the rare combination of interdependent electrical and thermal transport properties required to be present in a single material. The TE efficiency is defined by the figure of merit ZT=(S(2) σ) T/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the total thermal conductivity, and T is the absolute temperature. A new p-type thermoelectric material, CsAg5 Te3 , is presented that exhibits ultralow lattice thermal conductivity (ca. 0.18 Wm(-1)  K(-1) ) and a high figure of merit of about 1.5 at 727 K. The lattice thermal conductivity is the lowest among state-of-the-art thermoelectrics; it is attributed to a previously unrecognized phonon scattering mechanism that involves the concerted rattling of a group of Ag ions that strongly raises the Grüneisen parameters of the material.
authors: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China.
authors: Hua
authors: H
authors: Lin
authors: Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
authors: Gangjian
authors: 0000-0002-9087-4048
authors: G
authors: Tan
authors: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China.
authors: Jin-Ni
authors: JN
authors: Shen
authors: Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.
authors: Shiqiang
authors: S
authors: Hao
authors: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China. liming_wu@fjirsm.ac.cn.
authors: Li-Ming
authors: LM
authors: Wu
authors: Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA.|Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.
authors: Nicholas
authors: N
authors: Calta
authors: Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA.
authors: Christos
authors: C
authors: Malliakas
authors: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.|Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA.
authors: Si
authors: S
authors: Wang
authors: Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA.
authors: Ctirad
authors: C
authors: Uher
authors: Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.
authors: Christopher
authors: C
authors: Wolverton
authors: Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA. m-kanatzidis@northwestern.edu.
authors: Mercouri G
authors: MG
authors: Kanatzidis
keywords: CsAg5Te3; concerted rattling; thermoelectric materials; tunnel structure; ultralow thermal conductivity