High-Pressure Synthesis and Magnetic Property of a Novel Ferrimagnetic Quadruple Perovskite YMn₃Co₄O₁₂

Abstract

A novel quadruple perovskite oxide YMn₃Co₄O₁₂ has been synthesized in high-pressure and high-temperature conditions of 16 GPa and 1473 K, respectively. Rietveld refinement of synchrotron X-ray powder diffraction data reveals that this oxide crystallizes in a cubic quadruple perovskite structure in a space group of Im3 (No. 204) with a 1:3-type atomic ordering of Y and Mn at A-sites, and the bond valence analysis suggests the valence state of YMn³⁺₃Co³⁺₄O₁₂. A ferromagnetic-like transition is observed at ∼125 K and the magnetization value reaches up to ∼3 μ_B per formula unit at 5 K. The low-temperature magnetic state can be interpreted as ferrimagnetism with antiparallel alignment of A′-site Mn³⁺ (S = 2) and B-site Co³⁺ (high-spin, S = 2), which is in contrast to the antiferromagnetism in other A′-Mn-containing quadruple perovskite oxides. This finding proposes that the coexistence of A′-Mn³⁺ and B-Co³⁺ leading to ferrimagnetic state is realized in the specific structure with distinct crystallographic sites.

Fig. 1 Schematic of crystal structure of the quadruple perovskite YMn₃Co₄O₁₂. The metal-oxygen polyhedra, Mn ion at A′-site with pseudo-square coordination (purple) and Co ion at B-site with octahedral coordination (blue), are illustrated