Issue 9, 2021

Polytypism and superconductivity in the NbS2 system


We report on the phase formation and the superconducting properties in the NbS2 system. Specifically, we have performed a series of standardized solid-state syntheses in this system, which allow us to establish a comprehensive synthesis map for the formation of the two polytypes 2H-NbS2 and 3R-NbS2, respectively. We show that the identification of two polytypes by means of X-ray diffraction is not always unambiguous. Our physical property measurements on a phase-pure sample of 3R-NbS2, on a phase-pure sample of 2H-NbS2, and a mixed phase sample confirm earlier reports that 2H-NbS2 is a bulk superconductor and that 3R-NbS2 is not a superconductor above T = 1.75 K. Our results clearly show that specific heat measurements, as true bulk measurements, are crucial for the identification of superconducting materials in this and related systems. Our results indicate that for the investigation of van der Waals materials great care has to be taken on choosing the synthesis conditions for obtaining phase pure samples.

Graphical abstract: Polytypism and superconductivity in the NbS2 system

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Article information

Article type
20 Oct 2020
08 Feb 2021
First published
12 Feb 2021
This article is Open Access
Creative Commons BY license

Dalton Trans., 2021,50, 3216-3223

Polytypism and superconductivity in the NbS2 system

C. Witteveen, K. Górnicka, J. Chang, M. Månsson, T. Klimczuk and F. O. von Rohr, Dalton Trans., 2021, 50, 3216 DOI: 10.1039/D0DT03636F

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