Search for the magnetic structure of a distorted Kagome CrNiAs

Kagome metals, with a frustrated sub-lattice, are ideal hosts for many exquisite quantum phenomena. Taking the kagome-metal Co3Sn2S2 for example, the nodal ring transforms into Weyl nodes under strong spin-orbit coupling (SOC), with intrinsic Berry curvature and ferromagnetic order contributing to a giant anomalous Hall effect. We recently synthesized a distorted Kagome single crystal CrNiAs with an anomalous Hall effect, similar to the Co3Sn2S2 compound. The ternary arsenide CrNiAs is a ferromagnet with the Curie temperature, Tc, reported to be 171.9 K, and the magnetic moment per formula unit reported to be 2.42 μB in powder. The hyperfine magnetic moment field at 61Ni nuclei implies that the Ni atoms carry a magnetic moment of 0.15(3) μB, and the moment carried by the Cr atoms is 0.95(6) μB. From powder neutron diffraction experiments, the compound is ferromagnetic mainly from the Cr moment of 1.25(5) μB in the 110-182 K. Below 110 K, it reveals typical satellite reflections whose propagation vector is 0.228 c*. The behavior of the anomalous Hall effect with temperature is the same as that of the moment. So measuring the magnetic structure of CrNiAs is crucial to explain its anomalous Hall effect. We have already prepared large crystals sized up to 3 mm. We propose to do neutron Laue diffraction at 4 K 100 K, and 200 K (reference point) using the top-loading CCR at the single crystal diffractometer SXD. The measurements will take about 5 days.

笼目金属（Kagome）具有受挫子晶格，是诸多精妙量子现象的理想载体。以笼目金属Co₃Sn₂S₂为例，在强自旋轨道耦合（spin-orbit coupling, SOC）作用下，其节点环会转变为外尔节点，本征贝里曲率（Berry curvature）与铁磁序共同催生了巨反常霍尔效应。我们近期合成了一种兼具反常霍尔效应的畸变笼目单晶CrNiAs，其性质与Co₃Sn₂S₂类似。该三元砷化物CrNiAs为铁磁体，其居里温度（Curie temperature, Tc）据报道为171.9 K，粉体中每化学式单元的磁矩为2.42 μ_B。61Ni原子核处的超精细磁矩场表明，Ni原子的磁矩为0.15(3) μ_B，Cr原子的磁矩为0.95(6) μ_B。通过粉末中子衍射实验可知，在110~182 K温区，该化合物的铁磁性主要来源于Cr原子的1.25(5) μ_B磁矩；在110 K以下时，会出现典型的卫星反射，其传播矢量为0.228 c*。反常霍尔效应随温度的变化规律与磁矩的变化规律完全一致，因此解析CrNiAs的磁结构对于解释其反常霍尔效应至关重要。我们已制备出尺寸可达3 mm的大尺寸单晶，计划利用单晶衍射仪SXD的顶装式闭式循环制冷器（top-loading CCR），分别在4 K、100 K与200 K（参考点）下开展中子劳厄衍射实验，整个实验周期约为5天。

搜集汇总

背景与挑战

背景概述

该数据集包含在ISIS中子与μ子源进行的实验数据，旨在研究扭曲Kagome结构CrNiAs的磁结构，以解释其反常霍尔效应。实验使用SXD单晶衍射仪进行中子劳厄衍射，测量温度涵盖4 K、100 K和200 K，数据格式为RAW/Nexus，计划于2028年2月26日发布。