Proximity Induced Magnetic Anisotropy and Trefoil Fermiology in Monolayer FeCl 2 /Bi(111)
Authors:
- Shigemi TerakawaShigemi Terakawa
- Frank SchindlerFrank Schindler
- Titus NeupertTitus Neupert
- Jing‐Rong JiJJJing‐Rong Ji
- Gabriele DomaineGDGabriele Domaine
- Emily C. McFarlaneEMEmily C. McFarlane
- Daiyu GengDGDaiyu Geng
- Jiabao YangJYJiabao Yang
- Fadi ChoueikaniFadi Choueikani
- Philippe OhresserPhilippe Ohresser
- Manuel ValvidaresManuel Valvidares
Open Access
- 19 February 2026
- journal article
- Published by Wiley in Advanced Materials
- Vol. 38 (16) , e21534
Abstract
Interfaces between magnetic and non‐magnetic materials play a crucial role in various magnetic heterostructures. The emergence of 2D van der Waals (vdW) magnets has introduced new opportunities for exploring proximity effects in vdW heterostructures. While the influence of magnetic layers on nearby non‐magnetic materials has been widely studied, it remains unclear whether non‐magnetic substrates can similarly modulate the intrinsic magnetic properties of 2D magnets, particularly their magnetic anisotropy. In this work, by analyzing X‐ray magnetic circular dichroism spectra of an epitaxially grown FeCl 2 monolayer on a Bi(111) surface, a reorientation of magnetic anisotropy is observed – from its natural out‐of‐plane to a predominantly in‐plane alignment. This effect vanishes in bilayer FeCl 2 /Bi(111), where the magnetic anisotropy reverts to its intrinsic out‐of‐plane orientation, consistent with the layered antiferromagnetic order of bulk FeCl 2 . Angle‐resolved photoelectron spectroscopy reveals the presence of metallic interface states derived from the Bi surface states, accompanied by charge transfer and emergence of a moiré potential that gives rise to a distinctive trefoil‐shaped Fermi surface. These results demonstrate that non‐magnetic substrates can exert strong proximity influence on the magnetic and electronic behavior of 2D vdW magnets, offering new strategies for engineering magnetic anisotropy and electronic structure in spintronic heterostructures.Keywords
Funding Information
- Japan Society for the Promotion of Science (24K23032)
- Generalitat Valenciana (CIDEGENT/2021/005)
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (TMCG‐2213805)
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (215040)
- Deutsche Forschungsgemeinschaft (314790414)
- European Research Council (101117424)
This publication has 66 references indexed in Scilit:
- Ferromagnetic Order in 2D Layers of Transition Metal DichloridesAdvanced Materials, 2024
- Atomic‐Scale Visualization of Multiferroicity in Monolayer NiI2Advanced Materials, 2024
- An insulating and easy magnetization-plane magnet: The DFT + U and constrained electron population study of 1 T-FeCl2Computational Materials Science, 2023
- Epitaxial Monolayers of the Magnetic 2D Semiconductor FeBr2 Grown on Au(111)Chemistry of Materials, 2023
- Prospects and Opportunities of 2D van der Waals Magnetic SystemsAnnalen der Physik, 2020
- Two‐Dimensional Magnets: Forgotten History and Recent Progress towards Spintronic ApplicationsAdvanced Functional Materials, 2019
- Enhancing the perpendicular magnetic anisotropy of 1T-FeCl2 monolayer by applying strain: first-principles studyJournal of Magnetism and Magnetic Materials, 2017
- The iron L edges: Fe 2p X-ray absorption and electron energy loss spectroscopyJournal of Electron Spectroscopy and Related Phenomena, 2013
- Surface pre-melting and surface flattening of Bi nanofilms on Si(111)-7×7Surface Science, 2003
- The structure of FeCl2 at high pressuresJournal of Physics and Chemistry of Solids, 1975