发表机构
National Institute of Technology Andhra Pradesh; Indian Institute of Technology Delhi; Indian Institute of Technology Hyderabad; UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC Campus; Indian Institute of Science Education and Research, Berhampur（安得拉邦国立技术学院; 德里印度理工学院; 海德拉巴印度理工学院; UGC-DAE科学研究联盟孟买中心BARC校区; 贝赫拉姆普尔科学教育与研究印度学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合实验与理论，探究四元赫斯勒合金FeRuMnGe的无序对磁基态的调控作用，揭示无序驱动其磁态转变并关联竞争性磁相互作用与玻璃态磁行为。
AI 中文摘要
本项结合实验与理论的研究，探讨了无序在调控四元赫斯勒合金FeRuMnGe磁基态中的作用。在FeRuMnZ（Z=Ga、Si）系列中，化学取代会改变原子有序度与电子结构，进而产生不同的磁基态。受此启发，我们将该系列扩展至FeRuMnGe。X射线衍射结果显示，样品存在B2型反位无序，即Fe与Ru、Mn与Ge发生原子互混。理论计算表明，此类无序会改变交换相互作用，引发竞争性铁磁与反铁磁耦合，并使系统从半金属态转变为金属态。磁测量结果显示，竞争性相互作用会产生团簇玻璃态，与长程磁有序共存。在冻结温度Tf处未观测到热力学特征，结合交流磁化率与弛豫测量结果，证实了短程磁相互作用与玻璃态磁的存在。该化合物在约161K以下呈现增强的磁响应，在5T磁场下的最大磁化强度约为1.64μB/每化学式单位。总体而言，本研究建立了四元赫斯勒合金中反位无序、竞争性交换相互作用与玻璃态磁性之间的直接关联。结合实验结果与理论计算还揭示，无序驱动该系统从FeRuMnSi中的反铁磁主导态转变为FeRuMnGe中的铁磁主导态，为理解无序程度在调控四元赫斯勒合金（QHAs）磁性能中的作用提供了更深入的见解。
英文摘要
In this combined experimental and theoretical study, we investigate the role of disorder in governing the magnetic ground state of the quaternary Heusler alloy FeRuMnGe. In the FeRuMnZ (Z = Ga, Si) series, chemical substitution modifies atomic ordering and electronic structure, resulting in distinct magnetic ground states. Motivated by this, we extend the series to FeRuMnGe. X-ray diffraction reveals B2-type antisite disorder, where Fe--Ru and Mn--Ge intermix. Theoretical calculations show that such disorder modifies exchange interactions, leading to competing ferromagnetic and antiferromagnetic couplings, and drives the system from half-metallic to metallic. Magnetic measurements reveal competing interactions, giving rise to a cluster-glass state coexisting with long-range magnetic order. The absence of a thermodynamic signature at $T_f$, together with ac susceptibility and relaxation measurements, supports the presence of short-range magnetic interactions and a glassy magnetic state. The compound exhibits an enhanced magnetic response below $\sim 161$ K and a maximum magnetization of $\sim 1.64~μ_B$/f.u. at 5 T. Overall, this work establishes a direct correlation between antisite disorder, competing exchange interactions, and glassy magnetism in quaternary Heusler alloys. Combined experimental results and theoretical calculations reveal that disorder drives the system from an AFM-dominated state in FeRuMnSi to an FM-dominated state in FeRuMnGe, providing deeper insight into the role of the extent of disorder in governing the magnetic properties of QHAs.
Comments21 pages, 13 figures, regular article
