Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe4GeTe2 far above room temperature

Hangtian Wang; Haichang Lu; Zongxia Guo; Ang Li; Peichen Wu; Jing Li; Weiran Xie; Zhimei Sun; Peng Li; Héloïse Damas; Anna Maria Friedel; Sylvie Migot; Jaafar Ghanbaja; Luc Moreau; Yannick Fagot-Revurat; Sébastien Petit-Watelot; Thomas Hauet; John Robertson; Stéphane Mangin; Weisheng Zhao; Tianxiao Nie

doi:10.1038/s41467-023-37917-8

Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe₄GeTe₂ far above room temperature

Nat Commun. 2023 Apr 29;14(1):2483. doi: 10.1038/s41467-023-37917-8.

Authors

Hangtian Wang^#^{1

2}, Haichang Lu^#^{3

4}, Zongxia Guo^{1

2}, Ang Li¹, Peichen Wu¹, Jing Li¹, Weiran Xie¹, Zhimei Sun⁵, Peng Li⁶, Héloïse Damas², Anna Maria Friedel^{2

7}, Sylvie Migot², Jaafar Ghanbaja², Luc Moreau², Yannick Fagot-Revurat², Sébastien Petit-Watelot², Thomas Hauet², John Robertson⁸, Stéphane Mangin⁹, Weisheng Zhao¹⁰, Tianxiao Nie¹¹

Affiliations

¹ Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
² Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France.
³ Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China. HaichangLu@buaa.edu.cn.
⁴ Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK. HaichangLu@buaa.edu.cn.
⁵ School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
⁶ Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA.
⁷ Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663, Kaiserslautern, Germany.
⁸ Engineering Department, Cambridge University, Cambridge, CB2 1PZ, UK.
⁹ Universite de Lorraine, Institut Jean Lamour, UMR CNRS 7198, Nancy, France. stephane.mangin@univ-lorraine.fr.
¹⁰ Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China. weisheng.zhao@buaa.edu.cn.
¹¹ Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China. nietianxiao@buaa.edu.cn.

^# Contributed equally.

Abstract

Despite recent advances in exfoliated vdW ferromagnets, the widespread application of 2D magnetism requires a Curie temperature (T_c) above room temperature as well as a stable and controllable magnetic anisotropy. Here we demonstrate a large-scale iron-based vdW material Fe₄GeTe₂ with the T_c reaching ~530 K. We confirmed the high-temperature ferromagnetism by multiple characterizations. Theoretical calculations suggested that the interface-induced right shift of the localized states for unpaired Fe d electrons is the reason for the enhanced T_c, which was confirmed by ultraviolet photoelectron spectroscopy. Moreover, by precisely tailoring Fe concentration we achieved arbitrary control of magnetic anisotropy between out-of-plane and in-plane without inducing any phase disorders. Our finding sheds light on the high potential of Fe₄GeTe₂ in spintronics, which may open opportunities for room-temperature application of all-vdW spintronic devices.