From ferromagnetic semiconductor to antiferromagnetic metal in epitaxial Cr x Te y monolayers

Abstract Chromium ditelluride, CrTe2, is an attractive candidate van der Waals material for hosting 2D magnetism. However, how the room-temperature ferromagnetism of the bulk evolves as the sample is thinned to the single-layer limit has proved controversial. This, in part, reflects its metastable n...

Full description

Saved in:
Bibliographic Details
Main Authors: Naina Kushwaha, Olivia Armitage, Brendan Edwards, Liam Trzaska, Jennifer Rigden, Peter Bencok, Deepnarayan Biswas, Tien-Lin Lee, Charlotte Sanders, Gerrit van der Laan, Peter Wahl, Phil D. C. King, Akhil Rajan
Format: Article
Language:English
Published: Nature Portfolio 2025-05-01
Series:npj Quantum Materials
Online Access:https://doi.org/10.1038/s41535-025-00772-5
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Chromium ditelluride, CrTe2, is an attractive candidate van der Waals material for hosting 2D magnetism. However, how the room-temperature ferromagnetism of the bulk evolves as the sample is thinned to the single-layer limit has proved controversial. This, in part, reflects its metastable nature, vs. a series of more stable self-intercalation compounds with higher relative Cr:Te stoichiometry. Here, exploiting a recently developed method for enhancing nucleation in molecular-beam epitaxy growth of transition-metal chalcogenides, we demonstrate the selective stabilisation of high-coverage CrTe2 and Cr2+ε Te3 epitaxial monolayers. Combining X-ray magnetic circular dichroism, scanning tunnelling microscopy, and temperature-dependent angle-resolved photoemission, we demonstrate that both compounds order magnetically with a similar T C. We find, however, that monolayer CrTe2 forms as an antiferromagnetic metal, while monolayer Cr2+ε Te3 hosts an intrinsic ferromagnetic semiconducting state. This work thus demonstrates that control over the self-intercalation of metastable Cr-based chalcogenides provides a powerful route for tuning both their metallicity and magnetic structure, establishing the CrxTey system as a flexible materials class for future 2D spintronics.
ISSN:2397-4648