Synthesis of Intrinsic Magnetic Topological Insulator MnBi 2n Te 3n+1 Family by Chemical Vapor Transport Method with Feedback Regulation

Abstract MnBi 2n Te 3n+1 is a representative family of intrinsic magnetic topological insulators, in which numerous exotic phenomena such as the quantum anomalous Hall effect are expected. The high‐quality crystal growth and magnetism manipulation are the most essential processes. Here a modified chemical vapor transport method using a feedback‐regulated strategy is developed, which provides the closed‐loop control of growth temperature within ± 0.1 °C. Single crystals of MnBi 2 Te 4 , MnBi 4 Te 7 , and MnBi 6 Te 10 are obtained under different temperature intervals respectively, and show variable tunability on magnetism by finely tuning the growth temperatures. Specifically, the cold‐end temperatures not only vary the strength of antiferromagnetic coupling in MnBi 2 Te 4 , but also induce magnetic ground state transitions from antiferromagnetism to ferromagnetism in MnBi 4 Te 7 and MnBi 6 Te 10 . In MnBi 2 Te 4 with optimized magnetism, quantized transport with Chern insulator state can be easily replicated. These results provide a systematic picture for the crystal growth and the rich magnetic tunability of MnBi 2n Te 3n+1 family, providing richer platforms for the related researches combining magnetism and topological physics.