標題: Heterostructured ferromagnet-topological insulator with dual-phase magnetic properties
作者: Chang, Shu-Jui
Chuang, Pei-Yu
Chong, Cheong-Wei
Chen, Yu-Jung
Huang, Jung-Chun Andrew
Chen, Po-Wen
Tseng, Yuan-Chieh
材料科學與工程學系
Department of Materials Science and Engineering
公開日期: 1-一月-2018
摘要: The introduction of ferromagnetism at the surface of a topological insulator (TI) produces fascinating spin-charge phenomena. It has been assumed that these fascinating effects are associated with a homogeneous ferromagnetic (FM) layer possessing a single type of magnetic phase. However, we obtained phase separation within the FM layer of a Ni80Fe20/Bi2Se3 heterostructure. This phase separation was caused by the diffusion of Ni into Bi2Se3, forming a ternary magnetic phase of Ni:Bi2Se3. The inward diffusion of Ni led to the formation of an FeSe phase outward, transforming the original Ni80Fe20/Bi2Se3 into a sandwich structure comprising FeSe/Ni:Bi2Se3/Bi2Se3 with dual-phase magnetic characteristics similar to that driven by the proximity effect. Such a phenomenon might have been overlooked in previous studies with a strong focus on the proximity effect. X-ray magnetic spectroscopy revealed that FeSe and Ni:Bi2Se3 possess horizontal and perpendicular magnetic anisotropy, respectively. The overall magnetic order of the heterostructure can be easily tuned by adjusting the thickness of the Bi2Se3 as it compromises the magnetic orders of the two magnetic phases. This discovery is essential to the quantification of spin-charge phenomena in similar material combinations where the FM layer is composed of multiple elements.
URI: http://dx.doi.org/10.1039/c8ra00068a
http://hdl.handle.net/11536/144559
ISSN: 2046-2069
DOI: 10.1039/c8ra00068a
期刊: RSC ADVANCES
Volume: 8
起始頁: 7785
結束頁: 7791
顯示於類別:期刊論文