Seminar on Magnetism
Group of Magnetism at the Department of Condensed Matter Physics
of Charles University and MGML has a pleasure to invite you to attend the joint seminar
on 27th May 2026 at 14:10
at Faculty of Mathematics and Physics of Charles University, Ke Karlovu 5, 121 16 Praha 2
Lecture room F2
Hayato Muto
DCMP, Faculty of Mathematics and Physics, Charles University
Orbital magnetism in van der Waals Antiferromagnet VBr3
Hayato Muto » Orbital magnetism in van der Waals Antiferromagnet VBr3
DCMP, Faculty of Mathematics and Physics, Charles University
Online link: cesnet.zoom.us Ask R. Colman for password.
Location: Lecture room F2, first floor of Ke Karlovu 5, 121 16 Prague 2
Spin-orbit coupling (SOC) contributes critically to the magnetic anisotropy that stabilizes long-range 2D magnetic order in van der Waals (vdW) magnets. In the first monolayer vdW ferromagnet CrI3, SOC at the heavy halide I− transfers to orbitally quenched Cr3+ (3d3, L = 0) via anisotropic superexchange, which stabilizes 2D ferromagnetism below 45 K [1]. In contrast, the vdW ferromagnetic Mott insulator VI3 hosts octahedrally coordinated V3+ (3d2, L = 1), where partially occupied t2g levels generate an unquenched orbital degree of freedom [2], which has been suggested to underlie a large orbital moment [3], strong magnetoelastic coupling [4], and anisotropic magnon excitations [5].
The isostructural compound VBr3 undergoes a structural transition at Ts = 90 K, followed by an antiferromagnetic transition at TN = 26.5 K. This compound exhibits strong uniaxial magnetocrystalline anisotropy with an easy c-axis and a metamagnetic transition from the antiferromagnetic state to a spin-polarized paramagnetic state [6]. A saturation magnetization of 1.2 μB/V and strong magnetic anisotropy suggest a large orbital contribution in this compound. However, both the low-temperature crystal structure and antiferromagnetic spin arrangement [7,8] are still under debate, and the orbital ground state has not yet been established.
In this talk, the TX3 (T: transition metal, X: halogen) compounds are briefly introduced through a comparison of CrX3 and VX3. Subsequently, the most intensively studied compound VI3 is reviewed. Finally, our polarized X-ray absorption study on VBr3 is presented. The suggested ground state and orbital magnetism of VBr3 will be discussed.
References:
[1] Y. Choi et al., Appl. Phys. Lett. 117, 022411 (2020).
[2] R. Sant et al., J. Phys.: Cond. Matt. 35, 405601 (2023).
[3] D. Hovančík et al., Nano Lett. 23, 1175 (2023).
[4] J. Valenta et al., Phys. Rev. B 103, 054424 (2021).
[5] Y. Gu et al., Phys. Rev. Lett. 132, 246702 (2024).
[6] D. Hovančík et al., Phys. Rev. B 108, 104416 (2023).
[7] M. Klicpera et al., J. Alloys Compd. 1008, 176544 (2024).
[8] Y. Gu et al., Phys. Rev. B 110, 064403 (2024).
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