Superconductivity and Magnetism in REFeAsO1-xFx (RE=Rare Earth Elements)

TL;DR

This study investigates fluoride-doped iron-based oxypnictides containing rare-earth elements, demonstrating high-temperature superconductivity and exploring how yttrium co-doping influences the critical temperature and magnetic properties.

Contribution

It reports the synthesis and characterization of GdFeAsO0.8F0.2 and Y-doped variants, revealing the effects of co-doping on superconducting transition temperature without altering crystal structure.

Findings

GdFeAsO0.8F0.2 exhibits superconductivity up to 43.9 K.

Yttrium co-doping lowers Tc by approximately 10 K.

Superconductivity and magnetic properties are affected by rare-earth element substitution.

Abstract

Fluoride-doped iron-based oxypnictides containing rare-earth gadolinium (GdFeAsO0.8F0.2) and co-doping with yttrium (Gd0.8Y0.2FeAsO0.8F0.2) have been prepared via conventional solid state reaction at ambient pressure. The non-yttrium substituted oxypnictide show superconducting transition as high as 43.9 K from temperature dependent resistance measurements with the Meissner effect observed at a lower temperature of 40.8 K from temperature dependent magnetization measurements. By replacing a small amount of gadolinium with yttrium Tc was observed to be lowered by 10 K which might be caused by a change in the electronic or magnetic structures since the crystal structure was not altered.