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

ABSTRACT

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 [Formula see text]-type perovskite structure with space group Im-3, where the Ca and Cu are 13 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.