Large Thermal Conductivity Reduction Induced by La/O Vacancies in the Thermoelectric LaCoO3 System

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• 作者：Yang Wang ; Fang Li ; Luxiang Xu ; Yu Sui ; Xianjie Wang ; Wenhui Su ; Xiaoyang Liu
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：May 16, 2011
• 年：2011
• 卷：50
• 期：10
• 页码：4412-4416
• 全文大小：802K
• 年卷期：v.50,no.10(May 16, 2011)
• ISSN：1520-510X

文摘

A series of compact La/O-vacant La_1鈥?i>xCoO_3鈥?i>y compounds were prepared by a cold high-pressure procedure, and their thermoelectric (TE) properties were investigated. Compared with the ion-substituted hole-type LaCoO₃ systems (e.g., La_1鈥?i>xSr_xCoO₃), the thermal conduction of La_1鈥?i>xCoO_3鈥?i>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鈥?i>xCoO_3鈥?i>y can be rationalized as a partially filled solid solution: La_1鈥?i>xxCoO_3鈥?i>yy, where denotes a vacancy. Such intrinsic thermal conductivity suppression provides an effective pathway for the design of better TE materials.