From Stoner to Local Moment Magnetism in Atomically Thin Cr2Te3

TL;DR

This study reveals a transition from Stoner to local moment magnetism in atomically thin Cr2Te3, demonstrating how dimensionality influences 2D ferromagnetic properties through comprehensive spectroscopic and theoretical analysis.

Contribution

It provides the first detailed spectroscopic investigation of the electronic structure evolution in 2D Cr2Te3, highlighting the transition from itinerant to localized ferromagnetism with decreasing thickness.

Findings

Observation of a Stoner to Heisenberg-type ferromagnetic transition in 2D Cr2Te3

Monolayer retains ferromagnetism with reduced Curie temperature

Dimensionality effectively tunes the magnetic properties of 2D Cr2Te3

Abstract

The field of two-dimensional (2D) ferromagnetism has been proliferating over the past few years, with ongoing interests in basic science and potential applications in spintronic technology. However, a high-resolution spectroscopic study of the 2D ferromagnet is still lacking due to the small size and air sensitivity of the exfoliated nanoflakes. Here, we report a thickness-dependent ferromagnetism in epitaxially grown Cr2Te3 thin films and investigate the evolution of the underlying electronic structure by synergistic angle-resolved photoemission spectroscopy, scanning tunneling microscopy, x-ray absorption spectroscopy, and first-principle calculations. A conspicuous ferromagnetic transition from Stoner to Heisenberg-type is directly observed in the atomically thin limit, indicating that dimensionality is a powerful tuning knob to manipulate the novel properties of 2D magnetism. Monolayer Cr2Te3 retains robust ferromagnetism, but with a suppressed Curie temperature, due to the drastic drop in the density of states near the Fermi level. Our results establish atomically thin Cr2Te3 as an excellent platform to explore the dual nature of localized and itinerant ferromagnetism in 2D magnets.