High-Pressure Synthesis of Quadruple Perovskite Oxide CaCu₃Cr₂Re₂O₁₂ with a High Ferrimagnetic Curie Temperature

An AA’₃B₂B’₂O₁₂-type quadruple perovskite oxide of CaCu₃Cr₂Re₂O₁₂ was synthesized at 18 GPa and 1373 K. Both an A- and B-site ordered quadruple perovskite crystal structure was observed, with the space group Pn-3. The valence states are verified to be CaCu₃²⁺Cr₂³⁺Re₂⁵⁺O₁₂ by bond valence sum calculations and synchrotron X-ray absorption spectroscopy. The spin interaction among Cu²⁺, Cr³⁺, and Re⁵⁺ generates a ferrimagnetic transition with the Curie temperature (T_C) at about 360 K. Moreover, electric transport properties and specific heat data suggest the presence of a half-metallic feature for this compound. The present study provides a promising quadruple perovskite oxide with above-room-temperature ferrimagnetism and possible half-metallic properties, which shows potential in the usage of spintronic devices.