Luo Jiangfan, Tong Qiwei, Jiang Zhicheng, Bai Hui, Wu Jinsong, Liu Xiaolin, Xie Sen, Ge Haoran, Zhao Yan, Liu Yong, Hong Min, Shen Dawei, Zhang Qingjie, Liu Wei, Tang Xinfeng
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China.
ACS Nano. 2023 Oct 10;17(19):19022-19032. doi: 10.1021/acsnano.3c04626. Epub 2023 Sep 21.
The discovery of MnBiTe-based intrinsic magnetic topological insulators has fueled tremendous interest in condensed matter physics, owing to their potential as an ideal platform for exploring the quantum anomalous Hall effect and other magnetism-topology interactions. However, the fabrication of single-phase MnBiTe films remains a common challenge in the research field. Herein, we present an effective and simple approach for fabricating high-quality, near-stoichiometric MnBiTe films by directly matching the growth rates of intermediate BiTe and MnTe. Through systematic experimental studies and thermodynamic calculations, we demonstrate that binary phases of BiTe and MnTe are easily formed during film growth, and the reaction of BiTe + MnTe → MnBiTe represents the rate-limiting step among all possible reaction paths, which could result in the presence of BiTe and MnTe impurity phases in the grown MnBiTe films. Moreover, BiTe and MnTe impurities introduce negative and positive anomalous Hall (AH) components, respectively, in the AH signals of MnBiTe films. Our work suggests that further manipulation of growth parameters should be the essential route for fabricating phase-pure MnBiTe films.
基于MnBiTe的本征磁性拓扑绝缘体的发现激发了凝聚态物理领域的巨大兴趣，这归因于它们作为探索量子反常霍尔效应及其他磁拓扑相互作用的理想平台的潜力。然而，单相MnBiTe薄膜的制备仍然是该研究领域的一个常见挑战。在此，我们提出一种有效且简单的方法，通过直接匹配中间相BiTe和MnTe的生长速率来制备高质量、接近化学计量比的MnBiTe薄膜。通过系统的实验研究和热力学计算，我们证明在薄膜生长过程中BiTe和MnTe的二元相很容易形成，并且BiTe + MnTe → MnBiTe反应是所有可能反应路径中的速率限制步骤，这可能导致在生长的MnBiTe薄膜中存在BiTe和MnTe杂质相。此外，BiTe和MnTe杂质分别在MnBiTe薄膜的反常霍尔（AH）信号中引入负的和正的反常霍尔分量。我们的工作表明，进一步控制生长参数应该是制备纯相MnBiTe薄膜的关键途径。
