Appearance of bulk superconductivity under hydrostatic pressure in Sr0.5RE0.5FBiS2 (RE = Ce, Nd, Pr, and Sm) compounds

Abstract

We report the appearance of superconductivity under hydrostatic pressure (0–2.5 GPa) in Sr0.5RE0.5FBiS2 with RE = Ce, Nd, Pr, and Sm. The studied compounds, being synthesized by solid state reaction route, are crystallized in tetragonal P4/nmm space group. At ambient pressure, though the RE = Ce exhibits the onset of superconductivity below 2.7 K, the Nd, Pr, and Sm samples are not superconducting down to 2 K. With application of hydrostatic pressure (up to 2.5 GPa), superconducting transition temperature (Tc) is increased to around 10 K for all the studied samples. The magneto-resistivity measurements are carried out on all the samples under 2.5 GPa pressure and their upper critical fields (Hc2) are determined. The superconductivity of these compounds appears to be quite robust against magnetic field. Summarily, the Sr0.5RE0.5FBiS2 compounds with RE = Ce, Nd, Pr, and Sm are successfully synthesized and superconductivity is induced in them under hydrostatic pressure.