title: Large thermal conductivity reduction induced by La/O vacancies in the thermoelectric LaCoO3 system.
abstract: A series of compact La/O-vacant La(1-x)CoO(3-y) compounds were prepared by a cold high-pressure procedure, and their thermoelectric (TE) properties were investigated. Compared with the ion-substituted hole-type LaCoO(3) systems (e.g., La(1-x)Sr(x)CoO(3)), the thermal conduction of La(1-x)CoO(3-y) is noticeably reduced by the La/O vacancies, whereas the electric transport is less influenced, which results in an efficient ZT enhancement. We demonstrate that the large thermal conductivity reduction originates from the strong point-defect scattering, and La(1-x)CoO(3-y) can be rationalized as a partially filled solid solution: La(1-x)◻(x)CoO(3-y)◻(y), where ◻ denotes a vacancy. Such intrinsic thermal conductivity suppression provides an effective pathway for the design of better TE materials.
authors.affiliation: Center for Condensed Matter Science and Technology (CCMST), Department of Physics, Harbin Institute of Technology, Harbin 150001, China. wang_yang@ntu.edu.sg
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Luxiang
authors.initials: L
authors.lastname: Xu
authors.forename: Yu
authors.initials: Y
authors.lastname: Sui
authors.forename: Xianjie
authors.initials: X
authors.lastname: Wang
authors.forename: Wenhui
authors.initials: W
authors.lastname: Su
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Liu