Polytypism and superconductivity in the NbS2 system. Issue 9 (12th February 2021)

• Record Type: Journal Article
• Authors: Witteveen, Catherine; Górnicka, Karolina; Chang, Johan; Månsson, Martin; Klimczuk, Tomasz; von Rohr, Fabian O.
• Is Part Of: Dalton transactions. Volume 50:Issue 9(2021)
• Page Start: 3216
• Page End: 3223
• Publication Date: 2021-02-12
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt03636f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : This work maps out the structure–property relations in the unique metallic van der Waals system of NbS2. Abstract : 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.