Abstract
In this paper, the effect of hole doping on the thermoelectric properties of the binary narrow-gap semiconducting intermetallic compound Ga 2Ru in the temperature range from 373 K to 973 K was investigated. We synthesized sintered pellets by spark plasma sintering (SPS) after arc-melting and succeeded in preparing crack-free samples. The maximum dimensionless figure of merit ZT max was 0.50 at 773 K for the sintered Ga 2Ru alloy. The temperature dependence of the electrical resistivity and its magnitude at 373 K dramatically changed from negative (∼11,000 μΩcm) to positive (∼200 μΩcm) upon hole doping by the substitution of Re for Ru atoms. Also, the Seebeck coefficient at 373 K changed from 300 μV/K to 75 μV/K. These changes were identified by the increase in carrier concentrations observed by Hall- effect measurements. In particular, large power factors (2.0 mW/m K 2 to 3.0 mW/m K 2) were obtained over a wide temperature range from 373 K to 973 K upon Re substitution. The lattice thermal conductivity beneficially decreased with increasing Re concentration as a result of an alloying effect.
Original language | English |
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Pages (from-to) | 1067-1072 |
Number of pages | 6 |
Journal | Journal of Electronic Materials |
Volume | 40 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2011 May 1 |
Externally published | Yes |
Keywords
- Nowotny chimney ladder
- Thermoelectric properties
- narrow-band-gap semiconductor
- ruthenium gallide
- spark plasma sintering
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry