Evolution of superconductivity and ferromagnetism in Eu(Fe_1−xRu_x)₂As₂

Abstract

Eu(Fe1−xRux)2As2 crystals were studied by resistivity and magnetization measurements. It is found that the SDW transition is gradually suppressed with the Ru doping and superconductivity with Tsc ~22 K emerges when x ≥0.2. The magnetic order of the Eu sublattice changes from A-type antiferromagnetic to ferromagnetic within x ≤0.2, making superconductivity and ferromagnetism coexist in a broad regime of 0.2 < x < 0.55.