Interfacial engineering of ferromagnetism in wafer-scale van der Waals Fe4GeTe2 far above room temperature
Hangtian Wang, Haichang Lu, Zongxia Guo, Ang Li, Pei-Chen Wu, Jing Li, Weiran Xie, Zhimei Sun, Peng Li, Héloïse Damas, Anna Maria Friedel, Sylvie Migot, Jaâfar Ghanbaja, Luc Moreau, Y. Fagot‐Révurat, S. Petit, Thomas Hauet, John Robertson, S. Mangin, Weisheng Zhao, Tianxiao Nie
Abstract
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 Fe 4 GeTe 2 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 Fe 4 GeTe 2 in spintronics, which may open opportunities for room-temperature application of all-vdW spintronic devices.