Superconductivity induced by phosphorus doping and its coexistence with ferromagnetism in EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$

TL;DR

This study reports the discovery of superconductivity at 26 K in EuFe₂(As₀.₇P₀.₃)₂ induced by phosphorus doping, which coexists with ferromagnetism of Eu²⁺ moments, demonstrating a rare coexistence in the ferro-arsenide family.

Contribution

First observation of superconductivity stabilized by internal chemical pressure in EuFe₂(As₀.₇P₀.₃)₂ with coexistence of ferromagnetism.

Findings

Superconductivity at 26 K induced by P doping.

Ferromagnetic ordering of Eu²⁺ moments at 20 K.

Coexistence of superconductivity and ferromagnetism.

Abstract

We have studied EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ by the measurements of x-ray diffraction, electrical resistivity, thermopower, magnetic susceptibility, magnetoresistance and specific heat. Partial substitution of As with P results in the shrinkage of lattice, which generates chemical pressure to the system. It is found that EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$ undergoes a superconducting transition at 26 K, followed by ferromagnetic ordering of Eu$^{2+}$ moments at 20 K. This finding is the first observation of superconductivity stabilized by internal chemical pressure, and supplies a rare example showing coexistence of superconductivity and ferromagnetism in the ferro-arsenide family.