TY - JOUR AU - Chen, Lebing AU - Chung, Jae-Ho AU - Chen, Tong AU - Duan, Chunruo AU - Schneidewind, Astrid AU - Radelytskyi, Igor AU - Voneshen, David J. AU - Ewings, Russell A. AU - Stone, Matthew B. AU - Kolesnikov, Alexander I. AU - Winn, Barry AU - Chi, Songxue AU - Mole, R. A. AU - Yu, D. H. AU - Gao, Bin AU - Dai, Pengcheng TI - Magnetic anisotropy in ferromagnetic CrI 3 JO - Physical review / B VL - 101 IS - 13 SN - 2469-9950 CY - Woodbury, NY PB - Inst. M1 - FZJ-2020-02490 SP - 134418 PY - 2020 AB - We use neutron scattering to show that ferromagnetic (FM) phase transition in the two-dimensional (2D)honeycomb lattice CrI3 is a weakly first order transition and controlled by spin-orbit coupling (SOC) inducedmagnetic anisotropy, instead of magnetic exchange coupling as in a conventional ferromagnet. With increasingtemperature, the magnitude of magnetic anisotropy, seen as a spin gap at the Brillouin zone center, decreasesin a power law fashion and vanishes at TC, while the in-plane and c-axis spin-wave stiffnesses associated withmagnetic exchange couplings remain robust at TC.We also compare parameter regimes where spin waves in CrI3can be described by a Heisenberg Hamiltonian with Dzyaloshinskii-Moriya interaction or a Heisenberg-KitaevHamiltonian. These results suggest that the SOC induced magnetic anisotropy plays a dominant role in stabilizingthe FM order in single layer 2D van der Waals ferromagnets. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000525840300002 DO - DOI:10.1103/PhysRevB.101.134418 UR - https://juser.fz-juelich.de/record/877883 ER -