English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  DetailsSummary

Released
Journal Article

Enhanced thermoelectric properties of the Zintl phase BaGa2Sb2 via doping with Na or K

MPS-Authors
/persons/resource/persons189216

Zevalkink,  Alex
Max Planck Institute for Chemical Physics of Solids, Max Planck Society;

/persons/resource/persons126787

Ormeci,  Alim
Max Planck Institute for Chemical Physics of Solids, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Aydemir, U., Zevalkink, A., Ormeci, A., Bux, S., & Snyder, G. J. (2016). Enhanced thermoelectric properties of the Zintl phase BaGa2Sb2 via doping with Na or K. Journal of Materials Chemistry A, 4(5), 1867-1875. doi:10.1039/c5ta07612a.


Cite as: https://hdl.handle.net/11858/00-001M-0000-0029-BC2A-7
Abstract
Na- or K-doped samples of Ba1-x(Na, K)(x)Ga2Sb2 were prepared by ball-milling followed by hot-pressing. The topological analysis of the electron density of BaGa2Sb2 implies a polar covalent nature of the Sb-Ga bonds in which the Sb atoms receive the electrons transferred from Ba rather than the Ga atoms. Successful doping of BaGa2Sb2 with Na or K was confirmed with combined microprobe and X-ray diffraction analysis. Alkali metal doping of BaGa2Sb2 increased the p-type charge carrier concentration to almost the predicted optimum values (similar to 10(20) h(+) cm(-3)) needed to achieve high thermoelectric performance. With increasing alkali metal concentration, electronic transport was shifted from non-degenerate semiconducting behaviour observed for BaGa2Sb2 to degenerate one for Na- or K-doped compounds. Overall, the thermoelectric figure of merit, zT, values reached up to similar to 0.65 at 750 K, considerably higher than the undoped sample (zT similar to 0.1 at 600 K), and a slight improvement relative to previously reported Zn-doped samples (similar to 0.6 at 800 K).