Abstract
We report the growth of the intrinsic magnetic topological system MnTe(Bi2Te3)n by molecular beam epitaxy. By mapping the temperature and the Bi:Mn flux ratio, it is shown that there is a narrow growth window for the n=1 phase MnBi2Te4 with 2.0<Bi:Mn<2.6 at 225 °C. Here the films are stoichiometric and excess Bi and Te is not incorporated. At higher flux ratios (Bi:Mn≥4.5) it is found that the n=2MnBi4Te7 phase is stabilized. Transport measurements indicate that the MnBi2Te4 and MnBi4Te7 undergo magnetic transitions around 25 and 10 K, respectively, consistent with antiferromagnetic phases found in the bulk. Further, for Mn-rich conditions (Bi:Mn<2), ferromagnetism emerges that exhibits a clear hysteretic state in the Hall effect, which likely indicates Mn-doped MnBi2Te4. Understanding how to grow ternary chalcogenide phases is the key to synthesizing new materials and to interface magnetism and topology, which together are routes to realize and control exotic quantum phenomena.
| Original language | English |
|---|---|
| Article number | 111201 |
| Journal | Physical Review Materials |
| Volume | 4 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 11 2020 |
Funding
This work has been partially supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (MBE growth, transport, and x-ray diffraction), and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy (part of MBE growth). Ion-beam analysis was performed at the Ion Beam Materials Laboratory located at the University of Tennessee, Knoxville. Y.Z. acknowledges support from Energy Dissipation to Defect Evolution (EDDE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (RBS). We would like to thank Jiaqiang Yan for insightful discussions.