Synchrotron powder X-ray diffraction and structural analysis of Eu0.5La0.5FBiS2-xSex

TL;DR

This study investigates the crystal structure of Eu0.5La0.5FBiS2-xSex, revealing how in-plane chemical pressure and disorder influence the emergence of bulk superconductivity in this BiS2-based system.

Contribution

It provides detailed structural analysis of Eu0.5La0.5FBiS2-xSex using synchrotron diffraction and Rietveld refinement, linking structural parameters to superconductivity.

Findings

Bulk superconductivity is induced by increased in-plane chemical pressure.

Structural parameters show decreased in-plane disorder with Se doping.

Precise structural analysis correlates with superconducting properties.

Abstract

Eu0.5La0.5FBiS2-xSex is a new BiS2-based superconductor system. In Eu0.5La0.5FBiS2-xSex, electron carriers are doped to the BiS2 layer by the substitution of Eu by La. Bulk superconductivity in this system is induced by increasing the in-plane chemical pressure, which is controlled by the Se concentration (x). In this study, we have analysed the crystal structure of Eu0.5La0.5FBiS2-xSex using synchrotron powder diffraction and the Rietveld refinement. The precise determination of the structural parameters and thermal factors suggest that the emergence of bulk superconductivity in Eu0.5La0.5FBiS2-xSex is achieved by the enhanced in-plane chemical pressure and the decrease in in-plane disorder.