Van der Waals magnet VI3 demonstrates intriguing magnetic properties that render it great for use in various applications. However, its microscopic magnetic structure has not been determined yet. Here, we report neutron diffraction and susceptibility measurements in VI3 that revealed a ferromagnetic order with the moment direction tilted from the c-axis by ~36{\deg} at 4 K. A spin reorientation accompanied by a structure distortion within the honeycomb plane is observed at a temperature of ~27 K, before the magnetic order completely disappears at TC = 50 K. The refined magnetic moment of ~1.3 μB at 4 K is considerably lower than the fully ordered spin moment of 2 μB/ V3+, suggesting the presence of a considerable orbital moment antiparallel to the spin moment and strong spin-orbit coupling in VI3. This results in strong magnetoelastic interactions that make the magnetic properties of VI3 easily tunable via strain and pressure.
@article{arxiv.2107.06443,
title = {Magnetic order and its interplay with structure phase transition in van der Waals ferromagnet VI$_3$},
author = {Yiqing Hao and Yiqing Gu and Yimeng Gu and Erxi Feng and Huibo Cao and Songxue Chi and Hua Wu and Jun Zhao},
journal= {arXiv preprint arXiv:2107.06443},
year = {2021}
}