An A-site-ordered AA'3B4O12-type quadruple perovskite oxide LaHg3Mn4O12 was prepared by using high-pressure and high-temperature methods. The compound crystallizes in cubic Im3̅ symmetry with a lattice parameter a = 7.5949(2) Å. The introduction of Hg2+ at the A' site leads to a significant increase in the Mn-O-Mn bond angle, up to 159.5°. A ferromagnetic phase transition is found to occur at the Curie temperature: TC ≈ 280 K, accompanied by a large saturation magnetic moment of 13.0 μB/f.u. A corresponding anomaly in the electrical resistivity is observed near TC. First-principles calculations reveal a half-metallic electronic band structure with a wide minority-spin energy gap of ∼2.0 eV, while the majority-spin states contribute to metallic electrical transport. The current sample, LaHg3Mn4O12 thus provides the first example of A'-site nonmagnetic quadruple perovskite oxide with half-metallic behavior. Moreover, compared with other isostructural RCu3Mn4O12 (R = rare earth and Bi) half-metals with magnetic Cu2+ at the A' site, LaHg3Mn4O12 exhibits significant enhancement in both the minority-spin energy gap and saturation magnetization, making it promising for potential spintronic applications.
Pi et al. (Wed,) studied this question.