The Hard Ferromagnetism in FePS3 Induced by Non-Magnetic Molecular Intercalation (Adv. Phys. Res. 2/2025)

Abstract

Anisotropic ferromagnetism within antiferromagnetic crystals

The cover feature showcases the emergence of hard anisotropic ferromagnetism following the intercalation of nonmagnetic pyridinium ions into antiferromagnetic FePS₃ single crystals. In article number 202400101, Yunbo Ou, Feng Liu, Seth Ariel Tongay, and colleagues report the transition from antiferromagnetism to ferromagnetism in pyridinium-intercalated FePS₃, thereby highlighting both the energetically stable B-phase and metastable P-phase. These phases exhibit remarkable properties, including giant coercive fields exceeding 7 T and high Curie temperatures (72–87 K). As revealed by X-ray photoelectron spectroscopy and supported by first-principles calculations and atomistic spin dynamics simulations, electron transfer from the pyridinium ions to FePS₃ plays a key role in driving this transition. This work offers crucial insights into hard magnetism in intercalated van der Waals materials, thus paving the way for advances in 2D magnet-based technologies.