Superconductivity induced by doping Platinum in BaFe2As2

TL;DR

This study demonstrates that doping platinum into BaFe2As2 induces superconductivity with a maximum Tc of about 25 K, showing that Pt substitution effectively suppresses magnetic order and structural transitions in this iron-based superconductor.

Contribution

The paper reports the successful synthesis of BaFe2-xPtxAs2 superconductors and establishes their phase diagram, highlighting platinum doping as an effective method to induce superconductivity in the FeAs family.

Findings

Superconductivity appears at x=0.02 doping level.

Maximum Tc of about 25 K at x=0.1.

Superconductivity can be induced by Pt doping similarly to Ni, Co, Rh, and Ir.

Abstract

By substituting Fe with the 5d-transition metal Pt in BaFe2As2, we have successfully synthesized the superconductors BaFe2-xPtxAs2. The systematic evolution of the lattice constants indicates that the Fe ions were successfully replaced by Pt ions. By increasing the doping content of Pt, the antiferromagnetic order and structural transition of the parent phase is suppressed and superconductivity emerges at a doping level of about x = 0.02. At a doping level of x = 0.1, we get a maximum transition temperature Tc of about 25 K. The synchrotron powder x-ray diffraction shows that the resistivity anomaly is in good agreement with the structural transition. The superconducting transitions at different magnetic fields were also measured at the doping level of about x = 0.1, yielding a slope of -dHc2/dT = 5.4 T/K near Tc. A phase diagram was established for the Pt doped 122 system. Our results suggest that superconductivity can also be easily induced in the FeAs family by substituting the Fe with Pt, with almost the similar maximum transition temperatures as doping Ni, Co, Rh and Ir.