AI 中文总结
本研究通过多种表征与计算，确定Fe$_{1+δ}$Sb为非共线非相对论自旋分裂反铁磁体，发现间隙Fe及Cr取代可调控其磁有序与性能，为相关研究提供新平台。
AI 中文摘要
非相对论自旋分裂（NRSS）反铁磁体是一类重要的磁性材料，结合了补偿磁性与动量依赖的自旋分裂，为自旋电子学应用提供了新机遇。本研究利用中子衍射、对分布函数、磁强计及密度泛函理论计算，对NiAs型Fe$_{1+δ}$Sb系列（δ=0.17-0.30）展开研究。中子衍射证实Fe$_{1+δ}$Sb采用非零传播矢量k=(1/3,1/3,0)的120°共面补偿磁有序；对分布函数精修显示，间隙Fe增加会抑制有序磁矩并诱发局域对称性降低。密度泛函理论预测其存在动量依赖的自旋分裂，以面外自旋极化为核心，具有奇宇称f波类对称性，确立该材料为非共线NRSS反铁磁体。鉴于Fe$_{1+δ}$Sb与已知变磁体CrSb结构相似，本研究进一步探究其固溶体，发现中等浓度Cr取代会产生铁磁分量与团簇自旋玻璃行为。这些结果确立Fe$_{1+δ}$Sb为非共线NRSS反铁磁性的新平台，证明金属间隙与取代是调控磁有序及性能的有效参数。
英文摘要
Non-relativistic spin-splitting (NRSS) antiferromagnets have recently emerged as an important class of magnetic materials that combine compensated magnetism with momentum-dependent spin splitting, offering new opportunities for spintronic applications. Here, we investigate a NiAs-type Fe$_{1+δ}$Sb series ($δ= 0.17$-0.30) using neutron diffraction, pair distribution function, magnetometry and density functional theory calculations. Neutron diffraction establishes that Fe$_{1+δ}$Sb adopts a $120^\circ$ coplanar compensated magnetic order with a non-zero propagation vector $\mathbf{k}=(1/3,\,1/3,\,0)$. Increasing interstitial Fe suppresses the ordered magnetic moment while inducing local symmetry lowering, as revealed by pair distribution function refinements. Density functional theory predicts momentum-dependent spin splitting, dominated by an out-of-plane spin polarization with an odd-parity f-wave-like symmetry, establishing the material as a non-collinear NRSS antiferromagnet. Motivated by the structural similarities between Fe$_{1+δ}$Sb and a known altermagnet CrSb, we further investigate their solid solution and find that Cr substitution at intermediate concentrations gives rise to a ferromagnetic component and a cluster spin-glass behavior. These results establish Fe$_{1+δ}$Sb as a new platform for non-collinear NRSS antiferromagnetism and demonstrate metal interstitial and substitution as effective parameters for tuning the magnetic order and properties.
