Superconductivity of F-substituted LnOBiS2 (Ln = La, Ce, Pr, Nd, Yb) compounds

TL;DR

This study reports the synthesis and characterization of F-substituted LnOBiS2 compounds, revealing superconductivity in La, Ce, Pr, Nd, and Yb variants, with some exhibiting coexistence of superconductivity and magnetic order.

Contribution

It is the first to demonstrate superconductivity in Ce, Pr, and Yb-based LnOBiS2 compounds and explores their structural, electrical, and magnetic properties.

Findings

Superconductivity observed at 1.9-5.4 K in all compounds.

YbO0.5F0.5BiS2 shows magnetic order at ~2.7 K.

Coexistence of superconductivity and magnetic order in Yb compound.

Abstract

Polycrystalline samples of F-substituted LnOBiS2 (Ln = La, Ce, Pr, Nd, Yb) compounds were synthesized by solid-state reaction. The samples were characterized by x-ray diffraction measurements and found to have the ZrCuSiAs crystal structure. Electrical resistivity and magnetic susceptibility measurements were performed on all of the samples and specific heat measurements were made on those with Ln = La, Ce, and Yb. All of these compounds exhibit superconductivity in the range 1.9 K - 5.4 K, which has not previously been reported for the compounds based on Ce, Pr, and Yb. The YbO0.5F0.5BiS2 compounds was also found to exhibit magnetic order at ~2.7 K that apparently coexists with superconductivity below 5.4 K.