Effects of Ga- and In-doping on the thermoelectric properties in Ba-Ge clathrate compounds

Norihiko Okamoto, Haruyuki Inui

Research output: Contribution to journalConference articlepeer-review


The crystal structures and thermoelectric properties of Ba-Ge type-I clathrate compounds (Ba8GaXGe46-X and Ba 8Ga16-YInYGe30) have been investigated as a function of Ga and In contents. Ba8Ga XGe46-X alloys have a crystal structure that contains an ordered arrangement of Ge vacancies, forming a superstructure based on the normal type-I structure until X reaches 3, whereas they have the normal type-I structure when X exceeds 3. The dimensionless thermoelectric figure of merit (ZT) increases with the increase in the Ga content, exhibiting the highest value of 0.49 for Ba8Ga16Ge30. The power factor for Ba8Ga10In6Ge30 is 1.5 times that for Ba8Ga16Ge30 so that the In containing alloy exhibits a ZT value as high as 1.03 at 700°C.

Original languageEnglish
Article numberS4.8
Pages (from-to)419-424
Number of pages6
JournalMaterials Research Society Symposium Proceedings
Publication statusPublished - 2005 Aug 26
Externally publishedYes
Event2004 MRS Fall Meeting - Boston, MA, United States
Duration: 2004 Nov 292004 Dec 2

ASJC Scopus subject areas

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


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