Van der Waals magnets appeared in 2017 [1] in the form of monolayers and since then, are stimulating a lot of experimental and theoretical efforts to understand and describe their properties to finally integrate them into spintronic or magnonic devices [2].

In this talk, I will describe the properties of an orthorhombic frustrated van der Waals magnet, CrOCl, that shows a wide variety of B field-induced magnetic phases characterized by magnetic cells much larger than the crystallographic cell. Together with a strong magneto-elastic coupling, this leads to pronounced zone folding effects in the phonon spectrum that provide a unique possibility to describe the B-field induced phases using Raman scattering techniques. I will describe the cascade of magnetic phases that bulk CrOCl exhibits when it is subjected to an external magnetic field, before the spin saturation at B=30T [3].

Finally, taking advantage of the weak van der Waals interlayer interaction, we can thin down these materials and I will describe from the view point of magneto-Raman scattering spectroscopy, the properties of thin layers of CrOCl, down to the monolayer limit.

[1] B. Huang et al., Nature 546, 270, (2017)

[2] J.F. Sierra et al., Nat. Nanotechnol.16, 856 (2021)

[3] A. Pawbake et al., ACS Nano 19, 23693, (2025)