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

Abstract

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
Pages39-43
Number of pages5
DOIs
Publication statusPublished - Dec 1 2012
Event2012 MRS Spring Meeting - San Francisco, CA, United States
Duration: Apr 9 2012Apr 13 2012

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1456
ISSN (Print)0272-9172

Other

Other2012 MRS Spring Meeting
CountryUnited States
CitySan Francisco, CA
Period4/9/124/13/12

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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    Liu, B., Saisho, M., Nagatomo, Y., Tajiri, M., Nakakohara, Y., Furukimi, O., Teranishi, R., & Munetoh, S. (2012). Synthesizing and subsequent annealing of Si-based thermoelectric material Ba8AuxSi46-x clathrates. In Nanoscale Thermoelectrics 2012 - Materials and Transport Phenomena (pp. 39-43). (Materials Research Society Symposium Proceedings; Vol. 1456). https://doi.org/10.1557/opl.2012.1512