Magnetism and topological Hall effect in antiferromagnetic Ru2MnSn-based Heusler compounds

• Published in: Journal of magnetism and magnetic materials Vol. 537; no. C; p. 168104
• Main Authors: Zhang, Wenyong, Balasubramanian, Balamurugan, Sun, Yang, Ullah, Ahsan, Skomski, Ralph, Pahari, Rabindra, Valloppilly, Shah R., Li, Xing-Zhong, Wang, Cai-Zhuang, Ho, Kai-Ming, Sellmyer, David J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2021; Elsevier BV; Elsevier
• Subjects: Alloys; Antiferromagnetism; Electromagnetism; Electron spin; Electron transport; Hall effect; Heusler compounds; Magnetic properties; Magnetism; Room temperature; Spin structure; Topological Hall effect; Topology; Transport phenomena; Antiferromagnetism; Topological Hall effect; Heusler compounds
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2021.168104

•Antiferromagnetic Ru2MnSn Heusler alloys with TN = 361 K.•Drastic changes in magnetic and electron-transport properties by varying the atomic Mn:Sn composition.•A diluted antiferromagnetic spin structure for Ru2Mn0.8Sn1.2 in which there are localized regions of uncompensated Mn spins.•Berry curvature in Ru2Mn0.8Sn1.2 due to a noncoplanar antiferromagnetic scissor mode.•Significant topological Hall effect originating from noncoplanar spin structure. Heusler compounds and alloys based on them are of great recent interest because they exhibit a wide variety of spin structures, magnetic properties, and electron-transport phenomena. Their properties are tunable by alloying and we have investigated L21-orderd compound Ru2MnSn and its alloys by varying the atomic Mn:Sn composition. While antiferromagnetic ordering with a Néel temperature of 361 K was observed in Ru2MnSn, the Mn-poor Ru2Mn0.8Sn1.2 alloy exhibits properties of a diluted antiferromagnet in which there are localized regions of uncompensated Mn spins. Furthermore, a noncoplanar spin structure, evident from a topological Hall-effect contribution to the room-temperature Hall resistivity, is realized in Ru2Mn0.8Sn1.2. Our combined experimental and theoretical analysis shows that in the Ru2Mn0.8Sn1.2 alloy, the magnetic properties can be explained in terms of a noncoplanar antiferromagnetic scissor mode, which creates a small net magnetization in a magnetic field and subsequently yields a Berry curvature with a strong topological Hall effect.