Lee, Sunghun Ji, Sanghyun Kim, Jinsu Cuong, Do Duc Rhim, Sonny H. Hong, Soon Cheol Park, Yun Chang Lee, Young Haeng Park, Dae Keun Toyama, Takeshi Gu, Jiyeong Jung, Myung-Hwa 2024-01-19T13:02:35Z 2024-01-19T13:02:35Z 2022-01-10 2022-01 0925-8388 https://pubs.kist.re.kr/handle/201004/115904 High-temperature ferromagnetism in materials composed of non-magnetic constituents is one of the most intriguing aspects in condensed matter physics as well as materials science. Beyond oxide compounds where the ferromagnetism is mainly induced by dilute magnetic dopants, a variety of unusual ferromagnetic materials, mostly fabricated artificially to control the magnetic and electronic properties, have been investigated for spintronic device applications. The unexpected ferromagnetism, attributed to strain and structural defects or proximity and interfacial effects, is now extended to quantum materials, despite prevailing controversy on its physical origin. Recently, the ferromagnetism observed in topological materials with high mobility arising from the linear energy dispersion invokes new interest in the field of spintronics. Here, we report experimental verification of peculiar high-temperature ferromagnetism in beta-Ag2Se topological semimetal, composed of non-magnetic constituents. We have fabricated stoichiometric Ag2Se (S-Ag2Se) and Ag-vacant Ag2Se (V-Ag2Se) samples. Contrary to non-magnetic behavior of S-Ag2Se, VAg2Se shows distinct ferromagnetic response up to room temperatures. First-principles calculations demonstrate that the ferromagnetic ordering occurs only in V-Ag2Se if there is finite Hubbard U, which can be explained by self-trapped magnetic polaron model with strong p-d hybridization. High-temperature ferromagnetism, especially in topological materials, allows exploring a significant new direction in material engineering for spintronic applications. (C) 2021 Elsevier B.V. All rights reserved. English Elsevier BV Ferromagnetism in beta-Ag2Se topological semimetal Article 10.1016/j.jallcom.2021.162025 1 Journal of Alloys and Compounds, v.891 Journal of Alloys and Compounds 891 N scie scopus 000709467600004 2-s2.0-85115961911 Chemistry, Physical Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Chemistry Materials Science Metallurgy & Metallurgical Engineering Article TRAPPED MAGNETIC POLARON ROOM-TEMPERATURE PHASE-TRANSITION THIN-FILMS INSULATORS STATE BULK Topological semimetal Ferromagnetism