Intrinsic 2D Ferromagnetism in V5Se8 Epitaxial Thin Films

• DOI: 10.1021/acs.nanolett.9b03614
• Publication Date: 2019-11-12T16:51:26Z
• Authors: Masaki Nakano; Yue Wang; Satoshi Yoshida; Hideki Matsuoka; Yuki Majima; Keisuke Ikeda; Yasuyuki Hirata; Yukiharu Takeda; Hiroki Wadati; Yoshimitsu Kohama; Yuta Ohigashi; Masato Sakano; Kyoko Ishizaka; Yoshihiro Iwasa
• Keywords: Condensed Matter - Materials Science; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 02 engineering and technology; 0210 nano-technology

The discoveries of intrinsic ferromagnetism in atomically-thin van der Waals crystals have opened up a new research field enabling fundamental studies on magnetism at two-dimensional (2D) limit as well as development of magnetic van der Waals heterostructures. To date, a variety of 2D ferromagnetism has been explored mainly by mechanically exfoliating 'originally ferromagnetic (FM)' van der Waals crystals, while bottom-up approach by thin film growth technique has demonstrated emergent 2D ferromagnetism in a variety of 'originally non-FM' van der Waals materials. Here we demonstrate that V5Se8 epitaxial thin films grown by molecular-beam epitaxy (MBE) exhibit emergent 2D ferromagnetism with intrinsic spin polarization of the V 3d electrons despite that the bulk counterpart is 'originally antiferromagnetic (AFM)'. Moreover, thickness-dependence measurements reveal that this newly-developed 2D ferromagnet could be classified as an itinerant 2D Heisenberg ferromagnet with weak magnetic anisotropy, broadening a lineup of 2D magnets to those potentially beneficial for future spintronics applications.