Tunable Magnetism in Atomically Thin Itinerant Antiferromagnet with Room-Temperature Ferromagnetic Order
Longyu Lu, Qing Wang, Hengli Duan, Kejia Zhu, Tao Hu, Yupeng Ma, Shengchun Shen, Yuran Niu, Jiatu Liu, Jianlin Wang, Sandy Adhitia Ekahana, Jan Dreiser, Yeong‐Ah Soh, Wensheng Yan, Guopeng Wang, Yimin Xiong, Ning Hao, Yalin Lu, Mingliang Tian
Abstract
Addressing the need for modulated spin configurations is crucial, as they serve as the foundational building blocks for next-generation spintronics, particularly in atomically thin structures and at room temperature. In this work, we realize intrinsic ferromagnetism in monolayer flakes and tunable ferro-/antiferromagnetism in (Fe 0.56 Co 0.44 ) 5 GeTe 2 antiferromagnets. Remarkably, the ferromagnetic ordering (≥1 L) and antiferromagnetic ordering (≥4 L) remain discernible up to room temperature. The T C (∼310 K) of the monolayer flakes sets a record high for known exfoliated monolayer van der Waals magnets. Within the framework of A-type antiferromagnetism, a notable odd–even layer-number effect at elevated temperatures ( T = 150 K) is observed. Of particular interest is the strong ferromagnetic order in even-layer flakes at low temperatures. The intricate interplay among magnetic field strength, layer number, and temperature gives rise to a diverse array of phenomena, holding promise not only for new physics but also for practical applications.