### 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 |
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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)