AI 中文总结
研究CeZn$_{2 - x}$Ga$_{2 + x}$单晶的结构和磁性，通过粉末中子衍射数据的反向蒙特卡罗分析，揭示磁性Ce位点局部晶体学无序，表明位置无序驱动相关竞争，导致自旋玻璃行为等，为在特定结构中设计受挫磁态提供了方法。
AI 中文摘要
四方BaAl$_4$（$I4/mmm$）母结构支撑着一类展现新奇现象的材料家族，包括向列超导、拓扑半金属性和重费米子行为。近期三元R-Zn-Ga化合物的生长探索了该家族中一些呈现稀土磁性的成员。本文报道了CeZn$_{2 - x}$Ga$_{2 + x}$（CeZn$_2$Ga$_2$的富Ga类似物）单晶的结构和磁性。其样品展现出与之前报道的CeZn$_2$Ga$_2$顺磁行为不同的磁性，观察到约4K的磁转变、低温下明显的变磁状态和强磁各向异性。虽批次间有差异表明对局部结构缺陷敏感，但晶体中始终存在磁转变和变磁状态。通过对收集的粉末中子衍射数据进行反向蒙特卡罗分析，揭示了磁性Ce位点存在显著局部晶体学无序。结果表明位置无序驱动了铁磁和反铁磁相关性竞争，导致观察到的自旋玻璃行为和复杂各向异性磁性。该研究表明调整局部晶体学无序可在BaAl$_4$型及类似金属间化合物结构中设计受挫磁态。
英文摘要
The tetragonal BaAl$_4$ ($I4/mmm$) parent structure underpins a diverse family of materials exhibiting novel phenomena, including nematic superconductivity, topological semimetallicity, and heavy fermion behavior. The recent growth of ternary R-Zn-Ga compounds, such as the previously reported CeZn$_2$Ga$_2$, has explored some of the members exhibiting rare-earth magnetism within this family. In this paper, we report on the structural and magnetic properties of single crystals of CeZn$_{2-x}$Ga$_{2+x}$, a Ga-rich analogue of CeZn$_2$Ga$_2$. Our CeZn$_{2-x}$Ga$_{2+x}$ samples exhibit magnetic properties distinct from the paramagnetic behavior previously reported for CeZn$_2$Ga$_2$. We observe a magnetic transition around 4 K, pronounced metamagnetic states at low temperatures, and strong magnetic anisotropy. Though there are batch-to-batch variations that suggest a strong sensitivity to local structural imperfections, we consistently see the presence of magnetic transitions and metamagnetic states in our crystals. To investigate the local structural sensitivity hypothesis, we performed Reverse Monte Carlo analysis of collected powder neutron diffraction data, revealing the presence of significant local crystallographic disorder of the magnetic Ce site. Our findings demonstrate that the positional disorder drives competing ferromagnetic and antiferromagnetic correlations that lead to the observed spin glass behavior and complex anisotropic magnetism. This study illustrates that tuning the local crystallographic disorder enables engineering frustrated magnetic states in BaAl$_4$-type and similar intermetallic structures.
Comments16 pages, 9 figures
