Synthesizing and subsequent annealing of Si-based thermoelectric material Ba8AuxSi46-x clathrates

Bin Liu, Makoto Saisho, Yuya Nagatomo, Mikihito Tajiri, Yusuke Nakakohara, Osamu Furukimi, Ryo Teranishi, Shinji Munetoh

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    We prepared the type-I Ba8AuxSi46-x (x=5.5, 5.4 and 5.33) clathrates with p-type conduction by arc-melting and subsequent annealing. The Seebeck coefficients of all as-synthesized samples were negative. After annealing, in the case of x=5.4 and 5.5, the Seebeck coefficients changed to positive, and in the case of x=5.33, this value was negative for the annealed sample. The chemical composition revealed that Au content in the Ba8AuxSi46-x clathrates increased after the annealing process. The backscattered electron images showed that there were many Au-excess regions which were not clathrate structure in the as-synthesized samples, and these regions decreased and even disappeared after the annealing process. The disappearing of Au-excess regions can be explained by the diffusion of Au atoms from the Au-excess regions into the clathrates. Based on these results, annealing treatment can be used to tune the carrier conduction by controlling the content of Au for type-I Ba8Au xSi46-x clathrates.

    Original languageEnglish
    Title of host publicationNanoscale Thermoelectrics 2012 - Materials and Transport Phenomena
    Number of pages5
    Publication statusPublished - 2012
    Event2012 MRS Spring Meeting - San Francisco, CA, United States
    Duration: Apr 9 2012Apr 13 2012

    Publication series

    NameMaterials Research Society Symposium Proceedings
    ISSN (Print)0272-9172


    Other2012 MRS Spring Meeting
    Country/TerritoryUnited States
    CitySan Francisco, CA

    All Science Journal Classification (ASJC) codes

    • General Materials Science
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering


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