Coexistence of ferromagnetism and superconductivity in the hybrid ruthenate-cuprate compound RuSr_2GdCu_2O_8 studied by muon spin rotation (\mu SR) and DC-magnetization

TL;DR

This study reveals that the hybrid ruthenate-cuprate compound RuSr₂GdCu₂O₈ exhibits coexisting ferromagnetism below 133 K and superconductivity below 16 K, with magnetic order remaining stable across the superconducting transition.

Contribution

It provides experimental evidence of microscopic coexistence of ferromagnetism and superconductivity in RuSr₂GdCu₂O₈ using muon spin rotation and magnetization techniques.

Findings

Ferromagnetic order of Ru moments below 133 K

Superconductivity appears at 16 K

Magnetic order remains unchanged at superconducting transition

Abstract

We have investigated the magnetic and the superconducting properties of the hybrid ruthenate-cuprate compound RuSr_{2}GdCu_{2}O_{8} by means of zero-field muon spin rotation- (ZF-$\mu $SR) and DC magnetization measurements. The DC-magnetisation data establish that this material exhibits ferromagnetic order of the Ru-moments ($\mu (Ru) \approx 1 \mu_{B}$) below T_{Curie} = 133 K and becomes superconducting at a much lower temperature T_c = 16 K. The ZF-$\mu $SR experiments indicate that the ferromagnetic phase is homogeneous on a microscopic scale and accounts for most of the sample volume. They also suggest that the magnetic order is not significantly modified at the onset of superconductivity.