Evaluation of the thermoelectric potential of the type-I clathrate Ba8NiyZnxGe46−x−y
| Autor: | Peter Rogl, S Seichter, E. Bauer, Esmaeil Royanian, Matthias Falmbigl, A. Grytsiv, Navida Nasir, A Zavarsky |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Materials science
Acoustics and Ultrasonics Condensed matter physics Clathrate hydrate Analytical chemistry Condensed Matter Physics Thermoelectric materials Surfaces Coatings and Films Electronic Optical and Magnetic Materials Thermal conductivity Electrical resistivity and conductivity Seebeck coefficient Thermoelectric effect Figure of merit Ternary operation |
| Zdroj: | Journal of Physics D: Applied Physics. 45:215308 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/0022-3727/45/21/215308 |
| Popis: | A detailed investigation of the high-temperature thermoelectric properties of the ternary clathrate of type-I Ba8Zn x Ge46−x for the range 7.2 ⩽ x ⩽ 7.8 is presented. Electrical resistivity, Seebeck coefficient, thermal conductivity and Hall-effect measurements clearly demonstrate that the maximum ZT-value can be expected for the composition Ba8Zn7.7Ge38.3, which reaches ZT ∼ 0.46 at a temperature of 730 K. Furthermore, the influence on the thermoelectric properties was studied for partial substitution of Zn by one Ni-atom (Ba8Ni y Zn x Ge46−x−y with y nom = 1, and 6.5 ⩽ x ⩽ 7.2) or by three Ni-atoms per unit cell (Ba8Ni y Zn x Ge46−x−y with y nom = 3 and x = 1 to 3). Whereas a small amount of Ni increases the figure of merit ZT to 0.65 at 800 K, a higher Ni-content reduces the thermoelectric performance. Hall-effect measurements reveal that this improvement is essentially due to an increased charge carrier mobility. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|