Rise and Fall of the Ferromagnetism in CrSBr Flakes by Non‐Magnetic Ion Irradiation

The magnetic phase transition is explored in CrSBr flakes through non‐magnetic ion irradiation, revealing a novel method for magnetic control in two‐dimensional (2D) materials. The rise and fall of the ferromagnetic phase is observed in antiferromagnetic CrSBr with increasing the irradiation fluence. The irradiated CrSBr shows ferromagnetic critical temperature ranging from 110 to 84 K, well above liquid N 2 temperature. Raman spectroscopy reveals phonon softening, suggesting the formation of defects. These findings not only highlight CrSBr's potential in spintronics, but also present ion irradiation as an effective tool for tuning magnetic properties in 2D materials, opening new avenues for the development of spintronic devices based on air‐stable van der Waals semiconductors.