Superconductivity in the Nb2SnC compound

TL;DR

This study demonstrates that Nb2SnC, a lamellar hexagonal compound, exhibits superconductivity with a critical temperature of 7.8K when synthesized under specific high-pressure and temperature conditions, marking the highest Tc reported for its phase.

Contribution

It is the first report of superconductivity in Nb2SnC, showing synthesis conditions critically influence its superconducting properties.

Findings

Superconductivity observed in Nb2SnC with Tc ~7.8K.

Optimal superconducting properties achieved at 2.5 GPa and 523°C.

Highest Tc reported for an H-phase compound to date.

Abstract

Nb2SnC is a member of the large family of lamellar materials that crystallize in the hexagonal structure with space group P63/mmc which are isomorphs with Cr2AlC, also named H-phase. In spite of the great number of compounds which belong to this family, the superconductivity has been reported only for two cases: Mo2GaC and Nb2SC. In this work we show that superconductivity can be observed in Nb2SnC depending on the synthesis method used. The quality of the superconductor is strongly dependent of the synthesis method and the optimal results were reached for samples synthesized at 2.5 GPa and 523 +/- 50oC. This sample showed a critical temperature close to 7.8K, revealed from magnetization and transport measurement, the highest critical temperature reported up to now for an H-phase.