We present the synthesis of a novel binary metal oxide material: Ba₇Mn₄O₁₅. The crystal structure has been investigated by high-resolution powder synchrotron X-ray diffraction in the temperature range of 100–300 K as well as by powder neutron diffraction at 10 and 80 K. This material represents an isostructural barium-substituted analogue of the layered material Sr₇Mn₄O₁₅ that forms its own structural class. However, we find that Ba₇Mn₄O₁₅ adopts a distinct magnetic ordering, resulting in a magnetoelectric ground state below 50 K. The likely magnetoelectric coupling mechanisms have been inferred from performing a careful symmetry-adapted refinement against the powder neutron diffraction experiments, as well as by making a comparison with the nonmagnetoelectric ground state of Sr₇Mn₄O₁₅.

中文翻译：

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磁电Ba7Mn4O15的合成与表征

我们提出了一种新型二元金属氧化物材料的合成：Ba ₇ Mn ₄ O ₁₅。晶体结构已通过 100–300 K 温度范围内的高分辨率粉末同步加速器 X 射线衍射以及 10 和 80 K 温度范围内的粉末中子衍射进行了研究。该材料代表了层状结构的等结构钡取代类似物材料 Sr ₇ Mn ₄ O ₁₅形成自己的结构类别。然而，我们发现 Ba ₇ Mn ₄ O ₁₅采用不同的磁序，导致磁电基态低于 50 K。可能的磁电耦合机制已通过对粉末中子衍射实验进行仔细的对称调整改进以及与非磁电基进行比较来推断Sr ₇ Mn ₄ O ₁₅的状态。