Unraveling the electronic structure and magnetic transition evolution across monolayer, bilayer, and multilayer ferromagnetic Fe3GeTe2
Date
2024-09-30
Authors
Roemer, Ryan
Lee, Dong Hyun David
Smit, Steef
Zhang, Xiyue
Godin, Simon
Hamza, V
Jian, Tianyi
Larkin, Josiah
Shin, H
Liu, Chong
Journal Title
Journal ISSN
Volume Title
Publisher
npj 2D Materials and Applications volume
ORCID
Type
Article
Degree Level
Abstract
Two-dimensional (2D) van der Waals (vdW) magnets have sparked widespread attention due to their potential in spintronic applications as well as in fundamental physics. Ferromagnetic vdW compound Fe3GeTe2 (FGT) and its Ga variants have garnered significant interest due to their itinerant magnetism, correlated states, and high magnetic transition temperature. Experimental studies have demonstrated the tunability of FGT’s Curie temperature, TC, through adjustments in quintuple layer numbers (QL) and carrier concentrations, n. However, the underlying mechanism remains elusive. In this study, we employ molecular beam epitaxy (MBE) to synthesize 2D FGT films down to 1 QL with precise layer control, facilitating an exploration of the band structure and the evolution of itinerant carrier density. Angle-resolved photoemission spectroscopy (ARPES) reveals significant band structure changes at the ultra-thin limit, while first-principles calculations elucidate the band evolution from 1 QL to bulk, largely governed by interlayer coupling. Additionally, we find that n is intrinsically linked to the number of QL and temperature, with a critical value triggering the magnetic phase transition. Our findings underscore the pivotal role of band structure and itinerant electrons in governing magnetic phase transitions in such 2D vdW magnetic materials.
Description
Keywords
magnets, angle-resolved photoemission spectroscopy, quintuple layer numbers
Citation
Degree
Department
Program
Advisor
Committee
Part Of
item.page.relation.ispartofseries
DOI
https://doi.org/10.1038/s41699-024-00499-0