Effects of Nb substitution on thermoelectric properties of CrSi2
| Autor: | Yoshihiko Iijima, Hiroki Nagai, Kei Hayashi, Yuzuru Miyazaki, Tomohisa Takamatsu |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Condensed matter physics Mechanical Engineering Metals and Alloys Analytical chemistry Spark plasma sintering 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Thermal conductivity Mechanics of Materials Electrical resistivity and conductivity Seebeck coefficient 0103 physical sciences Thermoelectric effect Materials Chemistry Crystallite 0210 nano-technology Dimensionless quantity |
| Zdroj: | Journal of Alloys and Compounds. 687:37-41 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2016.06.047 |
| Popis: | The effects of Nb substitution on the solubility range, lattice parameters, and thermoelectric properties of CrSi 2 with a C40-type structure have been investigated. Polycrystalline samples of Nb-substituted Cr 1− x Nb x Si 2 (0 ≤ x ≤ 0.15) have been prepared by a two-step arc-melting process, followed by spark plasma sintering. XRD patterns confirm that single-phase Cr 1− x Nb x Si 2 is obtained in the composition range 0 ≤ x ≤ 0.10. As x increases from 0 to 0.10, the a - and c -axis lengths increase linearly. For x > 0.10, the a - and c -axis lengths do not obey Vegard’s rule. The electrical conductivity of Cr 1− x Nb x Si 2 (0 ≤ x ≤ 0.10) increases with increasing x , although the Seebeck coefficient gradually decreases with increasing x over the entire temperature range. In addition, the total thermal conductivity decreases with increasing x , owing to the reduction in lattice thermal conductivity. As a consequence, the dimensionless figure-of-merit ZT max increases from 0.16 ( x = 0) at 600 K to 0.20 ( x = 0.05) at 700 K. |
| Databáze: | OpenAIRE |
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