The exploration of the non-collinear antiferromagnetic (AFM) phase holds promise for the discovery of zero thermal expansion (ZTE) materials, which is of great significance to resist the temperature effect in aerospace and precision engineering fields. Currently, there is still a lack of effective approaches to regulate this special AFM phase. In this work, a non-collinear AFM phase has been obtained in the anti-perovskite compound Mn₃Fe_0.2Co_0.2Ni_0.2Mn_0.2Cu_0.2N proposed by high-entropy engineering. Utilizing neutron powder diffraction (NPD) analysis, the magnetic structure is resolved to be a triangular AFM phase with a k = [0, 0, 0] and a ferromagnetic (FM) component located at the corner of the cubic structure, which belongs to the R-3 space group. Particularly, it presents ZTE behavior in a wide temperature range from 10 to 180 K. In-situ NPD analysis reveals that the negative thermal expansion attributed to magnetic evolution almost offsets the normal positive thermal expansion quantified by the Debye formula. Further first principles calculations reveal that the specific AFM phase derives from the AFM-type nearest neighboring magnetic exchange interactions and the easy-axis-type magnetic anisotropy. This demonstration offers an efficient strategy for designing magnetic structures and achieving ZTE over a wide temperature range.

中文翻译：

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高熵反钙钛矿 Mn3Fe0.2Co0.2Ni0.2Mn0.2Cu0.2N 中的零热膨胀行为


对非共线反铁磁 （AFM） 相的探索有望发现零热膨胀 （ZTE） 材料，这对于航空航天和精密工程领域的抵抗温度效应具有重要意义。目前，仍然缺乏有效的方法来调节这个特殊的 AFM 阶段。在本工作中，通过高熵工程提出的反钙钛矿化合物 Mn₃Fe_0.2Co_0.2Ni_0.2Mn_0.2Cu_0.2N 获得了非共线 AFM 相。利用中子粉末衍射 （NPD） 分析，磁性结构被解析为具有 k = [0， 0， 0] 的三角形 AFM 相，铁磁 （FM） 分量位于立方结构的拐角处，属于 R-3 空间群。特别是，它在 10 至 180 K 的宽温度范围内呈现 ZTE 的行为。原位 NPD 分析表明，归因于磁演化的负热膨胀几乎抵消了由德拜公式量化的正常正热膨胀。进一步的第一性原理计算表明，特定的 AFM 相位来自 AFM 型最近邻磁交换相互作用和易轴型磁各向异性。该演示为设计磁性结构和在宽温度范围内实现 ZTE 提供了一种有效的策略。