Abstract
The effects of Nb substitution on the solubility range, lattice parameters, and thermoelectric properties of CrSi2with a C40-type structure have been investigated. Polycrystalline samples of Nb-substituted Cr1-xNbxSi2(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 Cr1-xNbxSi2is 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 Cr1-xNbxSi2(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 ZTmaxincreases from 0.16 (x = 0) at 600 K to 0.20 (x = 0.05) at 700 K.
Original language | English |
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Pages (from-to) | 37-41 |
Number of pages | 5 |
Journal | Journal of Alloys and Compounds |
Volume | 687 |
DOIs | |
Publication status | Published - 2016 Jan 1 |
Keywords
- Carrier concentration
- Nb substitution
- Thermal conductivity
- Thermoelectric properties
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry