A new 3d–5d hybridization oxide, CaCu₃Mn₂Os₂O₁₂ (CCMOO), was prepared by high-pressure and high-temperature synthesis methods. The compound crystallizes to an A-site-ordered but B-site-disordered quadruple perovskite structure with a space group of Im3̅ (No. 204). The charge states of the transition metals are determined to be Cu²⁺/Mn^3.5+/Os^4.5+ by X-ray absorption spectroscopy. Although most B-site-disordered perovskites possess lower spin-ordering temperatures or even nonmagnetic transitions, the current CCMOO displays a long-range ferrimagnetic phase transition with a critical temperature as high as ∼280 K. Moreover, a large saturated magnetic moment is found to occur [7.8 μ_B/formula units (f.u.) at 2 K]. X-ray magnetic circular dichroism shows a Cu²⁺(↑)Mn^3.5+(↑)Os^4.5+(↓) ferrimagnetic coupling. The corner-sharing Mn/OsO₆ octahedra with mixed Mn and Os charge states make the compound metallic in electrical transport, in agreement with a specific heat fitting at low temperature. This work provides a rare example with high spin-ordering temperature and a large magnetic moment in B-site-disordered 3d–5d hybridization perovskite oxides.

中文翻译：

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B站点无序3d-5d杂化四方钙钛矿氧化物CaCu ₃ Mn ₂ Os ₂ O _12中的近室温铁磁有序

通过高压高温合成方法制备了一种新型的3d-5d杂化氧化物CaCu ₃ Mn ₂ Os ₂ O ₁₂（CCMOO）。该化合物结晶成A位有序但B位无序的四钙钛矿结构，其空间群为Im 3+（No. 204）。过渡金属的电荷态确定为Cu ²⁺ / Mn ^3.5+ / Os ^4.5+通过X射线吸收光谱法。尽管大多数B位置无序的钙钛矿具有较低的自旋序温度或什至非磁性跃迁，但当前的CCMOO表现出长范围的亚铁磁相变，其临界温度高达280K。此外，还发现了较大的饱和磁矩发生[7.8μ_乙以2 K /式单位（FU）]。X射线磁性圆二色性显示Cu ²⁺（↑）Mn ^3.5+（↑）Os ^4.5+（↓）亚铁磁耦合。拐角共享Mn / OsO ₆具有混合的Mn和Os电荷态的八面体使化合物在电传输中具有金属性，与低温下的特定热配合相符。这项工作提供了一个罕见的例子，该例子在B位无序3d-5d杂化钙钛矿氧化物中具有较高的自旋序温度和较大的磁矩。