New Insights into the Structure, Chemistry, and Properties of Cu₄SnS₄

Author

Amitava Choudhury, Missouri University of Science and TechnologyFollow
Sudip Mohapatra
Hooman Yaghoobnejad Asl
Senghuat Lee
Yew San Hor, Missouri University of Science and TechnologyFollow
Julia E. Medvedeva, Missouri University of Science and TechnologyFollow
Devon L. McClane
Greg Hilmas, Missouri University of Science and TechnologyFollow
Michael A. McGuire
Andrew May
Hsin Wang
Shreeram Dash
Aaron Welton
Punit Boolchand
Kasey P. Devlin
Jennifer A. Aitken
Regine Herbst-Irmer
Vaclav Petricek

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 m_e 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.

Recommended Citation

A. Choudhury and S. Mohapatra and H. Yaghoobnejad Asl and S. Lee and Y. S. Hor and J. E. Medvedeva and D. L. McClane and G. Hilmas and M. A. McGuire and A. May and H. Wang and S. Dash and A. Welton and P. Boolchand and K. P. Devlin and J. A. Aitken and R. Herbst-Irmer and V. Petricek, "New Insights into the Structure, Chemistry, and Properties of Cu₄SnS₄," Journal of Solid State Chemistry, vol. 253, pp. 192 - 201, Academic Press Inc., Sep 2017.

The definitive version is available at https://doi.org/10.1016/j.jssc.2017.05.033

Department(s)

Chemistry

Second Department

Physics

Third Department

Materials Science and Engineering

Keywords and Phrases

119-Sn Mossbauer; Band structure; Crystal structure; Cu4SnS4; Electronic properties; Phase transition; Thermoelectrics; Calculations; Energy gap; Local density approximation; Seebeck coefficient; Single crystals; Temperature; X ray diffraction

International Standard Serial Number (ISSN)

0022-4596

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Academic Press Inc., All rights reserved.

Publication Date

01 Sep 2017