Coexistence of Superconductivity and (Anti-)Ferromagnetism in RuSr₂YCu₂O₈

抄録

The coexistence of antiferromagnetism and superconductivity in the hybrid ruthenate-cuprate RuSr₂YCu₂O₈ synthesized under high pressure has been confirmed by means of powder neutron diffraction and resistivity measurements. The Ru moments are antiferromagnetically ordered at about 149 K and Ru spins can be aligned by applying a magnetic field, suggesting that the system gradually changes from antiferromagnetism to ferromagnetism. However, the superconductivity in the compound persists even at H=9 T. This indicates the coexistence of ferromagnetism and superconductivity under a high magnetic field.