Above-Room-Temperature Ferromagnetism in Thin van der Waals Flakes of Cobalt-Substituted Fe5GeTe2
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2023-01-05 |
| Journal | ACS Applied Materials & Interfaces |
| Authors | Hang Chen, Shahidul Asif, Kapildeb Dolui, Y. Wang, Jeyson TƔmara-Isaza |
| Institutions | Universidad Nacional de Colombia, University of Delaware |
| Citations | 23 |
Abstract
Section titled āAbstractāTwo-dimensional (2D) magnetic van der Waals materials provide a powerful platform for studying the fundamental physics of low-dimensional magnetism, engineering novel magnetic phases, and enabling thin and highly tunable spintronic devices. To realize high-quality and practical devices for such applications, there is a critical need for robust 2D magnets with ordering temperatures above room temperature that can be created via exfoliation. Here, the study of exfoliated flakes of cobalt-substituted Fe<sub>5</sub>GeTe<sub>2</sub> (CFGT) exhibiting magnetism above room temperature is reported. Via quantum magnetic imaging with nitrogen-vacancy centers in diamond, ferromagnetism at room temperature was observed in CFGT flakes as thin as 16 nm corresponding to 16 layers. This result expands the portfolio of thin room-temperature 2D magnet flakes exfoliated from robust single crystals that reach a thickness regime relevant to practical spintronic applications. The Curie temperature <i>T</i><sub>c</sub> of CFGT ranges from 310 K in the thinnest flake studied to 328 K in the bulk. To investigate the prospect of high-temperature monolayer ferromagnetism, Monte Carlo calculations were performed, which predicted a high value of <i>T</i><sub>c</sub> of ā¼270 K in CFGT monolayers. Pathways toward further enhancing monolayer <i>T</i><sub>c</sub> are discussed. These results support CFGT as a promising platform for realizing high-quality room-temperature 2D magnet devices.