Superconductivity at 11.3 K induced by cobalt doping in CeOFeAs

TL;DR

This study reports the synthesis of a new cobalt-doped CeOFeAs superconductor exhibiting superconductivity at 11.3 K, with detailed structural characterization and analysis of doping effects on transition temperature.

Contribution

It introduces a new cobalt-doped CeOFeAs superconductor and provides detailed synthesis, structural, and superconducting property analysis, highlighting the doping dependence of Tc.

Findings

Superconductivity at 11.3 K in CeOFe0.9Co0.1As

Layered tetragonal ZrCuSiAs structure confirmed

Superconducting transition temperature decreases with increased cobalt doping

Abstract

Pure phases of a new oxyarsenide superconductor of the nominal composition CeOFe0.9Co0.1As was successfully synthesized by solid state reaction in sealed silica ampoules at 1180 C. It crystallizes in the layered tetragonal ZrCuSiAs type structure (sp gp P4/nmm) with lattice parameter of a = 3.9918(5) angstrom and c = 8.603(1) angstrom. A sharp superconducting transition is observed at 11.31 K with an upper critical field of 45.22 T at ambient pressure. The superconducting transition temperature is drastically lowered (~ 4.5, 4.9 K) on increasing the concentration (x = 0.15, 0.2) of cobalt.