### Abstract

We demonstrate the electrical and thermal transport properties of polycrystalline CoPn<inf>2</inf> (Pn = As and Sb) between 300 and 900 K. CoAs<inf>2</inf> shows semiconducting electrical transport up to 900 K, while CoSb<inf>2</inf> exhibits degenerate conduction. Sign inversion of the Seebeck coefficient is observed at ∼310 and ∼400 K for CoAs<inf>2</inf> and CoSb<inf>2</inf>, respectively. Thermal conductivity at 300 K is 11.7 Wm<sup>-1</sup>K<sup>-1</sup> for CoAs<inf>2</inf> and 9.4 Wm<sup>-1</sup>K<sup>-1</sup> for CoSb<inf>2</inf>. The thermoelectric power factor of CoAs<inf>2</inf> is ∼10 μWcm<sup>-1</sup>K<sup>-2</sup>, 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<inf>2</inf> and 0.26 eV for CoSb<inf>2</inf>.

Original language | English |
---|---|

Article number | 067147 |

Journal | AIP Advances |

Volume | 5 |

Issue number | 6 |

DOIs | |

Publication status | Published - 2015 Jun 1 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

**Electrical/thermal transport and electronic structure of the binary cobalt pnictides Co Pn <inf>2</inf> (Pn = As and Sb).** / Goto, Yosuke; Miyao, Syuhei; Kamihara, Yoichi; Matoba, Masanori.

Research output: Contribution to journal › Article

*AIP Advances*, vol. 5, no. 6, 067147. https://doi.org/10.1063/1.4923087

}

TY - JOUR

T1 - Electrical/thermal transport and electronic structure of the binary cobalt pnictides Co Pn 2 (Pn = As and Sb)

AU - Goto, Yosuke

AU - Miyao, Syuhei

AU - Kamihara, Yoichi

AU - Matoba, Masanori

PY - 2015/6/1

Y1 - 2015/6/1

N2 - We demonstrate the electrical and thermal transport properties of polycrystalline CoPn2 (Pn = As and Sb) between 300 and 900 K. CoAs2 shows semiconducting electrical transport up to 900 K, while CoSb2 exhibits degenerate conduction. Sign inversion of the Seebeck coefficient is observed at ∼310 and ∼400 K for CoAs2 and CoSb2, respectively. Thermal conductivity at 300 K is 11.7 Wm-1K-1 for CoAs2 and 9.4 Wm-1K-1 for CoSb2. The thermoelectric power factor of CoAs2 is ∼10 μWcm-1K-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 CoAs2 and 0.26 eV for CoSb2.

AB - We demonstrate the electrical and thermal transport properties of polycrystalline CoPn2 (Pn = As and Sb) between 300 and 900 K. CoAs2 shows semiconducting electrical transport up to 900 K, while CoSb2 exhibits degenerate conduction. Sign inversion of the Seebeck coefficient is observed at ∼310 and ∼400 K for CoAs2 and CoSb2, respectively. Thermal conductivity at 300 K is 11.7 Wm-1K-1 for CoAs2 and 9.4 Wm-1K-1 for CoSb2. The thermoelectric power factor of CoAs2 is ∼10 μWcm-1K-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 CoAs2 and 0.26 eV for CoSb2.

UR - http://www.scopus.com/inward/record.url?scp=84933057038&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84933057038&partnerID=8YFLogxK

U2 - 10.1063/1.4923087

DO - 10.1063/1.4923087

M3 - Article

AN - SCOPUS:84933057038

VL - 5

JO - AIP Advances

JF - AIP Advances

SN - 2158-3226

IS - 6

M1 - 067147

ER -