CrSBr is a van der Waals magnetic semiconductor exhibiting antiferromagnetic order below 140 K. It has emerged as a promising platform for engineering 2D magnetism because its intertwined electronic, optical, and magnetic properties can be profoundly modified via external stimuli such as electrical gating or magnetic fields. However, other strategies for tuning magnetism in layered materials, such as molecular intercalation, remain largely unexplored for CrSBr. Here, we demonstrate that the intercalation of tetramethylammonium (TMA) and tetrapropylammonium (TPA) ions into CrSBr induces a transition from antiferromagnetic to ferromagnetic order, while significantly enhancing the magnetic transition temperature to 190 K (TMA) and 230 K (TPA). The resulting intercalates are air-stable and exhibit large, hysteretic magnetoresistance exceeding 60% at 50 K in the TPA case. Besides, intercalation introduces symmetry-breaking structural changes in each CrSBr plane, revealed by Raman microscopy and corroborated by density functional theory (DFT) calculations. These findings highlight molecular intercalation as a powerful and versatile route to tailor the magnetic properties of CrSBr and unlock its potential to fabricate robust, high-temperature 2D magnetic devices.
@article{arxiv.2602.20940,
title = {Ferromagnetism above 200 K in organic-ion intercalated CrSBr},
author = {Sofia Ferreira-Teixeira and Daniel Tezze and Maria Ramos and Covadonga Álvarez-García and Bertuğ Bayındır and Junhyeon Jo and Beatriz Martín-García and Maider Ormaza and Fèlix Casanova and Samuel Mañas-Valero and Eugenio Coronado and Hasan Sahin and Luis E. Hueso and Marco Gobbi},
journal= {arXiv preprint arXiv:2602.20940},
year = {2026}
}
Comments
19 pages, 5 figures. This version is the original submitted manuscript (pre-peer-review) of the article published in ACS Nano (2025), DOI: 10.1021/acsnano.5c08747. Data underlying the main-manuscript figures of the published article are available at Zenodo, DOI: 10.5281/zenodo.18751202