Skip to Main content Skip to Navigation
Journal articles

Transport and Thermoelectric Coefficients of the Co 9 S 8 Metal: A Comparison with the Spin Polarized CoS 2

Abstract : A Co9S8 dense ceramic sintered by spark plasma sintering has been characterized by X-ray powder diffraction and transmission electron microscopy (diffraction and high resolution). This allowed magnetic, electronic, and thermal transport measurements to be made for a cubic (a = 9.927(2)Å) Co9S8 sample free of impurities and structural defects. The magnetic susceptibility and magnetic field dependence of the magnetization point toward an antiferromagnetic state, whereas the four-probe resistivity reveals a very metallic behavior with ρ300 K = 80 μΩ.cm described by a classical electron phonon model. When compared to CoS2, even if Co9S8 exhibits lower ρ values associated with the lack of ferromagnetic fluctuations existing in the former, the Co9S8 thermoelectric power factor, negative as in CoS2, is smaller, nonetheless leading to a power factor (PF) reaching PF ≈ 0.5 mW m–1 K–2 at 300 K. In Co9S8, with its low ρ going with a very high electronic part of the thermal conductivity κ, the lattice part of κ is smaller than that of CoS2 (∼2 W m–1 K–1 for Co9S8 at 300 K) suggesting that the more complex structure of Co9S8, with two different types of CoSn polyhedra, plays an important role.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-03451768
Contributor : Valerie Pralong Connect in order to contact the contributor
Submitted on : Friday, November 26, 2021 - 4:04:53 PM
Last modification on : Saturday, June 25, 2022 - 9:57:21 AM

Identifiers

Citation

Sylvie Hébert, Tristan Barbier, David Berthebaud, Oleg Lebedev, Valérie Pralong, et al.. Transport and Thermoelectric Coefficients of the Co 9 S 8 Metal: A Comparison with the Spin Polarized CoS 2. Journal of Physical Chemistry C, American Chemical Society, 2021, D. D. Sarma Festschrift, 125 (9), pp.5386-5391. ⟨10.1021/acs.jpcc.0c11601⟩. ⟨hal-03451768⟩

Share

Metrics

Record views

7