Issue 28, 2019

Structural stability and thermoelectric performance of high quality synthetic and natural pyrites (FeS2)

Abstract

Synthetic bulk and natural pyrite from the hydrothermal mine in Schönbrunn (Saxony, Germany) are confirmed to be stoichiometric FeS2 compounds and stable (for thermoelectric applications) up to ∼600 K by combined thermal, chemical, spectroscopic and X-ray diffraction analyses. Natural pyrite with a small amount (<0.6 wt%) of well-defined transition metal carbonates revealed characteristics of a nondegenerate semiconductor and is suitable as a model system for the investigation of thermoelectric performance. In the temperature range 50–600 K both natural and synthetic high quality bulk FeS2 samples show electrical resistivity and Seebeck coefficients varying within 220–5 × 10−3 Ω m and 4 – (−450) μV K−1, respectively. The large thermal conductivity (∼40 W m−1 K−1 at 300 K) is exclusively due to phononic contribution, showing a well pronounced maximum centered at ∼75 K for natural pyrite (grain size ≤5 mm). It becomes almost completely suppressed in the sintered bulk samples due to the increase of point defect concentration and additional scattering on the grain boundaries (grain size ≤100 μm). The thermoelectric performance of pure pyrite with ZT ∼ 10−6 at 600 K is indeed by a factor of ∼1000 worse than those reported earlier for some minerals and synthetic samples.

Graphical abstract: Structural stability and thermoelectric performance of high quality synthetic and natural pyrites (FeS2)

Supplementary files

Article information

Article type
Paper
Submitted
07 May 2019
Accepted
16 Jun 2019
First published
27 Jun 2019

Dalton Trans., 2019,48, 10703-10713

Structural stability and thermoelectric performance of high quality synthetic and natural pyrites (FeS2)

E. Zuñiga-Puelles, R. Cardoso-Gil, M. Bobnar, I. Veremchuk, C. Himcinschi, C. Hennig, J. Kortus, G. Heide and R. Gumeniuk, Dalton Trans., 2019, 48, 10703 DOI: 10.1039/C9DT01902B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements