Superconductivity at 14K in the Co-doped SmFe0.9Co0.1AsO

TL;DR

This study demonstrates that Co doping in SmFeAsO induces superconductivity at 14K by suppressing magnetic order, with detailed magnetic and superconducting properties characterized.

Contribution

First report of superconductivity at 14K in Co-doped SmFeAsO using a simple solid-state synthesis method.

Findings

Superconductivity at 14K confirmed by magnetization measurements.

Co doping suppresses SDW magnetic order in SmFeAsO.

Bulk superconductivity evidenced by diamagnetic loops at 2 and 5K.

Abstract

We report superconductivity in the SmFe0.9Co0.1AsO system being prepared by most easy and versatile single step solid-state reaction route. The parent compound SmFeAsO is non-superconducting but shows the spin density wave (SDW) like antiferromagnetic ordering at around 140K. To destroy the antiferromagnetic ordering and to induce the superconductivity in the parent system, the Fe2+ is substituted partially by Co3+. Superconductivity appears in SmFe0.9Co0.1AsO system at around 14K. The Co doping suppresses the SDW anomaly in the parent compound and induces the superconductivity. Magnetization measurements show clearly the onset of superconductivity with Tcdia at 14K. The isothermal magnetization measurements exhibit the lower critical fields (Hc1) to be around 200Oe at 2 K. The bulk superconductivity of the studied SmFe0.9Co0.1AsO sample is further established by open diamagnetic M(H) loops at 2, and 5K. Normal state (above Tc) linear isothermal magnetization M(H) plots excluded presence of any ordered magnetic impurity in the studied compound.