Intrinsic 2D Ferromagnetism in V5Se8 Epitaxial Thin Films

• Published in: Nano letters Vol. 19; no. 12; pp. 8806 - 8810
• Main Authors: Nakano, Masaki, Wang, Yue, Yoshida, Satoshi, Matsuoka, Hideki, Majima, Yuki, Ikeda, Keisuke, Hirata, Yasuyuki, Takeda, Yukiharu, Wadati, Hiroki, Kohama, Yoshimitsu, Ohigashi, Yuta, Sakano, Masato, Ishizaka, Kyoko, Iwasa, Yoshihiro
• Format: Journal Article
• Language: English
• Published: American Chemical Society 11.12.2019
• Subjects: anomalous Hall effect; X-ray magnetic circular dichroism; molecular-beam epitaxy; 2D magnet; vanadium selenide
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.9b03614

The discoveries of intrinsic ferromagnetism in atomically thin van der Waals crystals have opened a new research field enabling fundamental studies on magnetism at two-dimensional (2D) limit as well as development of magnetic van der Waals heterostructures. Currently, a variety of 2D ferromagnetism has been explored mainly by mechanically exfoliating “originally ferromagnetic (FM)” van der Waals crystals, while a 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 exhibit emergent 2D ferromagnetism with intrinsic spin polarization of the V 3d electrons despite that the bulk counterpart is “originally antiferromagnetic”. 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.