Electrical/thermal transport and electronic structure of the binary cobalt pnictides CoPn{sub 2} (Pn = As and Sb)

Journal Article · Mon Jun 15 00:00:00 EDT 2015 · AIP Advances

DOI:https://doi.org/10.1063/1.4923087· OSTI ID:22493910

Goto, Yosuke; Miyao, Syuhei; Kamihara, Yoichi; Matoba, Masanori ^[1]

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1. Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan)

We demonstrate the electrical and thermal transport properties of polycrystalline CoPn{sub 2} (Pn = As and Sb) between 300 and 900 K. CoAs{sub 2} shows semiconducting electrical transport up to 900 K, while CoSb{sub 2} exhibits degenerate conduction. Sign inversion of the Seebeck coefficient is observed at ∼310 and ∼400 K for CoAs{sub 2} and CoSb{sub 2}, respectively. Thermal conductivity at 300 K is 11.7 Wm{sup −1}K{sup −1} for CoAs{sub 2} and 9.4 Wm{sup −1}K{sup −1} for CoSb{sub 2}. The thermoelectric power factor of CoAs{sub 2} is ∼10 μWcm{sup −1}K{sup −2}, although the dimensionless figure of merit is limited to ∼0.1 due to relatively high thermal conductivity. Using electronic structure calculations, the band gap value is calculated to be 0.55 eV for CoAs{sub 2} and 0.26 eV for CoSb{sub 2}.

• OSTI ID: 22493910
• Journal Information: AIP Advances, Vol. 5, Issue 6; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ANTIMONIDES
COBALT
COBALT ARSENIDES
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
ENERGY GAP
EV RANGE
PERFORMANCE
POLYCRYSTALS
SEEBECK EFFECT
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THERMAL CONDUCTIVITY
THERMOELECTRIC PROPERTIES