Center for Condensed Matter and Materials Physics, Department of Physics, Beihang University, Beijing 100191, PR China.
Inorg Chem. 2012 Jul 2;51(13):7232-6. doi: 10.1021/ic300978x. Epub 2012 Jun 21.
The antiperovskite Mn(3)ZnN is studied by neutron diffraction at temperatures between 50 and 295 K. Mn(3)ZnN crystallizes to form a cubic structure at room temperature (C1 phase). Upon cooling, another cubic structure (C2 phase) appears at around 177 K. Interestingly, the C2 phase disappears below 140 K. The maximum mass concentration of the C2 phase is approximately 85% (at 160 K). The coexistence of C1 and C2 phase in the temperature interval of 140-177 K implies that phase separation occurs. Although the C1 and C2 phases share their composition and lattice symmetry, the C2 phase has a slightly larger lattice parameter (Δa ≈ 0.53%) and a different magnetic structure. The C2 phase is further investigated by neutron diffraction under high-pressure conditions (up to 270 MPa). The results show that the unusual appearance and disappearance of the C2 phase is accompanied by magnetic ordering. Mn(3)ZnN is thus a valuable subject for study of the magneto-lattice effect and phase separation behavior because this is rarely observed in nonoxide materials.
反钙钛矿结构 Mn(3)ZnN 的中子衍射研究在 50 至 295 K 温度范围内进行。室温下 Mn(3)ZnN 结晶形成立方结构（C1 相）。冷却时，在 177 K 左右出现另一种立方结构（C2 相）。有趣的是，C2 相在 140 K 以下消失。C2 相的最大质量浓度约为 85%（在 160 K 时）。在 140-177 K 的温度区间内 C1 和 C2 相共存表明发生了相分离。尽管 C1 和 C2 相具有相同的组成和晶格对称性，但 C2 相的晶格参数略有增大（Δa ≈ 0.53%），且具有不同的磁结构。进一步在高压条件（高达 270 MPa）下通过中子衍射对 C2 相进行研究。结果表明，C2 相的异常出现和消失伴随着磁有序。由于在非氧化物材料中很少观察到这种现象，因此 Mn(3)ZnN 是研究磁晶格效应和相分离行为的重要对象。
