A novel ferrimagnetic irido-cuprate: IrSr2GdCu2O8

摘要

We have performed all investigation of the structural, microstructural and magnetic properties of the new compound IrSr2GdCu2O8. The sample was prepared under high temperature (similar to 1393 K) and high-pressure conditions (similar to 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) x a(p) x 3a(p) which is supported by XRD, through a "diagonal" one, similar to root 2a(p) x root 2a(p) x 3a(p) 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. (C) 2006 Elsevier Inc. All rights reserved.