Thermoelectric properties of partly Sb- and Zn-substituted Ba(8)Ga(16)Ge(30) clathrates
2010 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 108, no 11, 113711- p.Article in journal (Refereed) Published
The effects on the thermoelectric properties of n-Ba(8)Ga(16)Ge(30) when substituting small amounts of the Ga or Ge with Sb or Zn have been investigated. A number of syntheses were prepared in quaternary systems of Ba(8)Ga(16)Ge(30) substituted with either Sb or Zn but only three samples were found to yield single phase products with nominal compositions of Ba(8)Ga(15)Sb(1)Ge(30), Ba(8)Ga(15)Zn(1)Ge(30) and Ba(8)Ga(16)Ge(28)Zn(2), respectively. When Ge was substituted for Zn the resulting sample remained n-type and an increase in thermopower and a decrease in thermal conductivity were achieved. These positive effects were accompanied with an increased electrical resistivity and thus the ZT was only somewhat improved up to about 400 degrees C. When substituting Ga with either Sb or Zn samples remained n-type but showed decreased thermopower and increased electrical resistivity and thermal conductivity. It is thus concluded that substitution of Ga with Zn or Sb is detrimental for the thermoelectric properties of Ba(8)Ga(16)Ge(30), whereas substitution of Ge with Zn appears a potent method for improving its performance.
Place, publisher, year, edition, pages
2010. Vol. 108, no 11, 113711- p.
IdentifiersURN: urn:nbn:se:su:diva-66230DOI: 10.1063/1.3518043ISI: 000285474100071OAI: oai:DiVA.org:su-66230DiVA: diva2:467628
authorCount :32011-12-192011-12-192011-12-19Bibliographically approved