Superconductivity in Se-doped new materials EuSr2Bi2S4F4 and Eu2SrBi2S4F4

TL;DR

This study reports the discovery of superconductivity in Se-doped EuSr2Bi2S4F4 and Eu2SrBi2S4F4 materials, with critical temperatures around 2.3 to 2.9 K, highlighting the effects of Se substitution.

Contribution

First demonstration of superconductivity in Se-doped EuSr2Bi2S4F4 and Eu2SrBi2S4F4, expanding the family of 3244 type superconductors with new Eu/Sr substitutions.

Findings

Superconductivity observed at Tc 2.9 K in EuSr2Bi2S4-xSexF4 (x=2)

Superconductivity at Tc 2.6-2.75 K in Eu2SrBi2S4-xSexF4 (x=1.5 and 2)

Se substitution induces superconductivity in these new materials.

Abstract

From our powder x ray diffraction pattern, electrical transport and magnetic studies we report the effect of isovalent Se substitution at S sites in the newly discovered systems EuSr2Bi2S4F4 and Eu2SrBi2S4F4. We have synthesized two new variants of 3244 type superconductor with Eu replaced by Sr which is reported elsewhere [Z. Haque et. al.]. We observe superconductivity at Tc 2.9 K (resistivity) and 2.3 K (susceptibility) in EuSr2Bi2S4-xSexF4 series for x = 2. In the other series Eu2SrBi2S4-xSexF4, two materials (x= 1.5; Tc = 2.6 K and x = 2; Tc = 2.75 K) exhibit superconductivity.