Charge carrier mediation and ferromagnetism induced in MnBi 6 Te 10 magnetic topological insulators by antimony doping

• Published in: Journal of physics. D, Applied physics Applied physics, 2022-03, Vol.55 (10), p.104002
• Main Authors: Xie, Hangkai, Fei, Fucong, Fang, Fenzhen, Chen, Bo, Guo, Jingwen, Du, Yu, Qi, Wuyi, Pei, Yufan, Wang, Tianqi, Naveed, Muhammad, Zhang, Shuai, Zhang, Minhao, Wang, Xuefeng, Song, Fengqi
• Format: Article
• Language: English
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/1361-6463/ac3790

A new kind of intrinsic magnetic topological insulator (MTI) MnBi 2 Te 4 family has shed light on the observation of novel topological quantum effects such as the quantum anomalous Hall effect (QAHE). However, strong anti-ferromagnetic (AFM) coupling and high carrier concentration in the bulk hinder practical applications. In closely related materials MnBi 4 Te 7 and MnBi 6 Te 10 , the interlayer magnetic coupling is greatly suppressed by Bi 2 Te 3 layer intercalation. However, AFM is still the ground state in these compounds. Here, by magnetic and transport measurements, we demonstrate that a Sb substitutional dopant plays a dual role in MnBi 6 Te 10 , which can not only adjust the charge carrier type and concentration, but also induces the solid into a ferromagnetic (FM) ground state. The AFM ground state region, which is also close to the charge neutral point, can be found in the phase diagram of Mn(Sb x Bi 1− x ) 6 Te 10 when x ∼ 0.25. An intrinsic FM-MTI candidate is thus demonstrated, which may take us a step closer to realizing a high-quality and high-temperature QAHE and related topological quantum effects in the future.