Abstract
MnBi2Te4 (MBT) materials are promising antiferromagnetic topological insulators in which field-driven ferromagnetism is predicted to cause a transition between axion insulator and Weyl semimetallic states. However, the presence of antiferromagnetic coupling between Mn/Bi antisite defects and the main Mn layer can reduce the low-field magnetization, and it has been shown that such defects are more prevalent in the structurally identical magnetic insulator MnSb2Te4 (MST). We use high-field magnetization measurements to show that the magnetization of MBT and MST occur in stages and full saturation requires fields of ∼60 T. As a consequence, the low-field magnetization plateau state in MBT, where many determinations of the quantum anomalous Hall state are studied, actually consists of ferrimagnetic septuple blocks containing both uniform and staggered magnetization components.
| Original language | English |
|---|---|
| Article number | 184429 |
| Journal | Physical Review B |
| Volume | 103 |
| Issue number | 18 |
| DOIs | |
| State | Published - May 28 2021 |
Funding
We thank Dr. J. Palmstrom, Dr. L. Stritzinger, and Dr. J. Singleton for their assistance with the measurement in the Pulsed Field Facility at LANL, and we appreciate the comments and discussions that Dr. J. Singleton provided that greatly improved the manuscript. This work was supported by the Center for the Advancement of Topological Semimetals, an Energy Frontier Research Center funded by the Department of Energy, Basic Energy Sciences, under Contract No. DE-AC02-07CH11358. L.K. acknowledges the support from the U.S. DOE Early Career Research Program. A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1644779 and the state of Florida. Research performed at ORNL is supported by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.