Presentation Information
[8a-E207-4]Competing Magnetic Interactions and Emergent Topological Transport in β-Mn-Type Co7Zn7Mn6 Chiral Magnet
〇(DC)Sneha Yadav1, Satoshi Sugimoto2, Shinya Kasai2, Sandip Chatterjee1 (1.Indian Institute of Technology (BHU) Varanasi, 2.National Institute for Materials Science, Japan)
Keywords:
Chiral magnet,Skyrmions,Magnetic Frustration
Magnetic skyrmions are topologically protected spin textures that exhibit nanoscale dimensions, high mobility under low current densities, and remarkable stability, making them promising candidates for next-generation spintronic devices. In chiral magnets, skyrmions emerge from the competition between symmetric exchange interaction and antisymmetric Dzyaloshinskii-Moriya interaction (DMI) arising from broken inversion symmetry. In β-Mn-type Co-Zn-Mn alloys, magnetic frustration introduced by Mn moments further enriches the magnetic phase diagram and influences skyrmion stability. However, stabilization of skyrmions at elevated temperatures remains a major challenge for practical applications. In this work, Ni substitution for Zn enhances the helimagnetic transition temperature (~265 K), suggesting strengthened magnetic interactions. As a consequence, the stability region of the skyrmion phase expands toward higher temperatures, 249-261K. The system exhibits a reentrant spin-glass state at low temperatures, which suggests the presence of multiple competing magnetic interactions. Such competition plays a crucial role in stabilizing nontrivial spin textures over an extended temperature range. The system shows bad-metallic behavior and pronounced negative magnetoresistance, reflecting suppression of spin-disorder scattering under applied magnetic fields. Hall-effect measurements reveal a finite topological Hall contribution associated with noncoplanar spin textures and emergent real-space Berry curvature. The observed transport anomalies correlate closely with the evolution of magnetic phases and demonstrate the influence of frustrated magnetism on charge-carrying electrons. These findings provide a viable strategy for engineering topological spin textures in chiral magnets and contribute to the development of skyrmion-based spintronic devices operating at technologically relevant temperatures.