New insights into the structure, chemistry, and properties of Cu4SnS4

DOI

10.1016/j.jssc.2017.05.033

Authors

Amitava Choudhury, Missouri University of Science and Technology
Sudip Mohapatra, Missouri University of Science and Technology
Hooman Yaghoobnejad Asl, Missouri University of Science and Technology
Seng Huat Lee, Missouri University of Science and Technology
Yew San Hor, Missouri University of Science and Technology
Julia E. Medvedeva, Missouri University of Science and Technology
Devon L. McClane, Missouri University of Science and Technology
Gregory E. Hilmas, Missouri University of Science and Technology
Michael A. McGuire, Oak Ridge National Laboratory
Andrew F. May, Oak Ridge National Laboratory
Hsin Wang, Oak Ridge National Laboratory
Shreeram Dash, University of Cincinnati
Aaron Welton, University of Cincinnati
Punit Boolchand, University of Cincinnati
Kasey P. Devlin, Duquesne University
Jennifer Aitken, Duquesne University
Regine Herbst-Irmer, Georg-August-Universität Göttingen
Váčlav Petříček, Institute of Physics of the Czech Academy of Sciences

Document Type

Journal Article

Publication Date

9-1-2017

Publication Title

Journal of Solid State Chemistry

Volume

253

First Page

192

Last Page

201

ISSN

224596

Keywords

119-Sn Mössbauer, Band structure, Crystal structure, Cu SnS 4 4, Electronic properties, Phase transition, Thermoelectrics

Abstract

The ambient temperature structure of Cu4SnS4 has been revisited and the recently reported low temperature structure has been confirmed from single-crystal X-ray diffraction data. A structural phase transition from a large monoclinic unit cell at low temperature to a smaller orthorhombic unit cell at high temperature has been observed. The room temperature phase exhibited disorder in the two copper sites, which is a different finding from earlier reports. The low temperature monoclinic form crystallizes in P21/c space group, which is isostructural with Cu4GeS4. The phase transition has also been studied with variable temperature powder X-ray diffraction and 119Sn Mössbauer spectroscopy. The Seebeck coefficients and electrical resistivity of polycrystalline Cu4SnS4 are reported from 16 to 400 K on hot pressed pellets. Thermal conductivity measurements at high temperatures, 350 – 750 K exhibited very low thermal conductivities in the range 0.28 – 0.35 W K–1 m–1. In all the transport measurements the phase transition has been observed at around 232 K. Resistivity decreases, while Seebeck coefficient increases after the phase transition during warming up from low to high temperatures. This change in resistivity has been correlated with the results of first-principles electronic band structure calculations using highly-accurate screened-exchange local density approximation. It was found that both the low hole effective mass of 0.63 me for the Γ→Y crystallographic direction and small band gap, 0.49 eV, are likely to contribute to the observed higher conductivity of the orthorhombic phase. Cu4SnS4 is also electrochemically active and shows reversible reaction with lithium between 1.7 and 3.5 volts.

Open Access

Green Accepted

Preprint

Link to Author Manuscript

Repository Citation

Choudhury, A., Mohapatra, S., Yaghoobnejad Asl, H., Lee, S., Hor, Y., Medvedeva, J., McClane, D., Hilmas, G., McGuire, M., May, A., Wang, H., Dash, S., Welton, A., Boolchand, P., Devlin, K., Aitken, J., Herbst-Irmer, R., & Petříček, V. (2017). New insights into the structure, chemistry, and properties of Cu4SnS4. Journal of Solid State Chemistry, 253, 192-201. https://doi.org/10.1016/j.jssc.2017.05.033