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DOE OSTI · 1615985

Magnetic anisotropy in ferromagnetic CrI 3

Chen, Lebing·Chung, Jae-Ho·Chen, Tong·Duan, Chunruo·Schneidewind, Astrid·Radelytskyi, Igor·Voneshen, David J.·Ewings, Russell A.·Stone, Matthew B.·Kolesnikov, Alexander I.·Winn, Barry L.·Chi, Songxue·Mole, R. A.·Yu, D. H.·Gao, Bin·Dai, Pengcheng
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Abstract

We use neutron scattering to show that ferromagnetic (FM) phase transition in the two-dimensional (2D) honeycomb lattice CrI 3 is a weakly first order transition and controlled by spin-orbit coupling (SOC) induced magnetic anisotropy, instead of magnetic exchange coupling as in a conventional ferromagnet. With increasing temperature, the magnitude of magnetic anisotropy, seen as a spin gap at the Brillouin zone center, decreases in a power law fashion and vanishes at T C , while the in-plane and c-axis spin-wave stiffnesses associated with magnetic exchange couplings remain robust at T C . We also compare parameter regimes where spin waves in CrI 3 can be described by a Heisenberg Hamiltonian with Dzyaloshinskii-Moriya interaction or a Heisenberg-Kitaev Hamiltonian. These results suggest that the SOC induced magnetic anisotropy plays a dominant role in stabilizing the FM order in single layer 2D van der Waals ferromagnets.

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Chen, Lebing, Chung, Jae-Ho, Chen, Tong, Duan, Chunruo, Schneidewind, Astrid, Radelytskyi, Igor, Voneshen, David J., Ewings, Russell A., Stone, Matthew B., Kolesnikov, Alexander I., Winn, Barry L., Chi, Songxue, Mole, R. A., Yu, D. H., Gao, Bin, Dai, Pengcheng. 2020-04-15. Magnetic anisotropy in ferromagnetic CrI 3. https://doi.org/10.1103/physrevb.101.134418

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