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arXiv · 2308.14349

Anisotropic magnetism and band evolution induced by ferromagnetic phase transition in titanium-based kagome ferromagnet SmTi3Bi4

Zhe Zheng·Long Chen·Xuecong Ji·Ying Zhou·Gexing Qu·Mingzhe Hu·Yaobo Huang·Hongming Weng·Tian Qian·Gang Wang
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Abstract

Kagome magnets with diverse topological quantum responses are crucial for next-generation topological engineering. The anisotropic magnetism and band evolution induced by ferromagnetic phase transition (FMPT) is reported in a newly discovered titanium-based kagome ferromagnet S mTi3 Bi4, which features a distorted Ti kagome lattice and S m atomic zig-zag chains. Temperature-dependent resistivity, heat capacity, and magnetic susceptibility reveal a ferromagnetic ordering temperature Tc of 23.2 K. A large magnetic anisotropy, observed by applying the magnetic field along three crystallographic axes, identifies the b axis as the easy axis. Angle-resolved photoemission spectroscopy with first-principles calculations unveils the characteristic kagome motif, including the Dirac point at the Fermi level and multiple van Hove singularities. Notably, a band splitting and gap closing attributed to FMPT is observed, originating from the exchange coupling between S m 4 f local moments and itinerant electrons of the kagome Ti atoms, as well as the time-reversal symmetry breaking induced by the long-range ferromagnetic order. Considering the large in-plane magnetization and the evolution of electronic structure under the influence of ferromagnetic ordering, such materials promise to be a new platform for exploring the intricate electronic properties and magnetic phases based on the kagome lattice.

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Zhe Zheng, Long Chen, Xuecong Ji, Ying Zhou, Gexing Qu, Mingzhe Hu, Yaobo Huang, Hongming Weng, Tian Qian, Gang Wang. 2024-02-07. Anisotropic magnetism and band evolution induced by ferromagnetic phase transition in titanium-based kagome ferromagnet SmTi3Bi4. https://doi.org/10.1007/s11433-023-2344-6

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