A novel ferrimagnetic irido-cuprate: IrSr2GdCu2O8

We have performed an investigation of the structural, microstructural and magnetic properties of the new compound IrSr₂GdCu₂O₈. The sample was prepared under high temperature (∼1393 K) and high-pressure conditions (∼60 Kbars) in a Belt type apparatus. X-ray diffraction (XRD) analysis shows that this irido-cuprate is isostructural with the corresponding Ru-1212 phase. Structurally, this material shows an interesting hierarchy of ordering phenomena, whose observation actually depends on the technique used to analyze the material: from a “simple” cell a_p×a_p×3a_p which is supported by XRD, through a “diagonal” one, as seen by SAED, to a microdomain texture of this last one cell supported by HREM. A ferrimagnetic Ir^IV-Gd^III spin ordering is observed below 15 K. The iridium oxidation state seems to be +4.