High-pressure synthesis and spin glass behavior of a Mn/Ir disordered quadruple perovskite CaCu₃Mn₂Ir₂O₁₂

A new 3d-5d hybridized quadruple perovskite oxide, CaCu₃Mn₂Ir₂O₁₂, was synthesized by high-pressure and high-temperature methods. The Rietveld structure analysis reveals that the compound crystallizes in an -type perovskite structure with space group Im-3, where the Ca and Cu are 1:3 ordered at fixed atomic positions. At the B site the 3d Mn and the 5d Ir ions are disorderly distributed due to the rare equal  +4 charge states for both of them as determined by x-ray absorption spectroscopy. The competing antiferromagnetic and ferromagnetic interactions among Cu²⁺, Mn⁴⁺, and Ir⁴⁺ ions give rise to spin glass behavior, which follows a conventional dynamical slowing down model. (paper)