Abstract
Millimeter-sized MnBi2Te4 single crystals are grown out of a Bi-Te flux and characterized using magnetic, transport, scanning tunneling microscopy, and spectroscopy measurements. The magnetic structure of MnBi2Te4 below TN is determined by powder and single-crystal neutron diffraction measurements. Below TN = 24 K, Mn2+ moments order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is 4.04(13)μB/Mn at 10 K and aligned along the crystallographic c axis in an A-type antiferromagnetic order. Below TN, the electrical resistivity drops upon cooling or when going across the metamagnetic transition in increasing magnetic fields. A critical scattering effect is observed in the vicinity of TN in the temperature dependence of thermal conductivity, indicating strong spin-lattice coupling in this compound. However, no anomaly is observed in the temperature dependence of thermopower around TN. Fine tuning of the magnetism and/or electronic band structure is needed for the proposed topological properties of this compound. The growth protocol reported in this work might be applied to grow high-quality crystals where the electronic band structure and magnetism can be finely tuned by chemical substitutions.
| Original language | English |
|---|---|
| Article number | 064202 |
| Journal | Physical Review Materials |
| Volume | 3 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 7 2019 |
Funding
Work at ORNL and Ames Laboratory was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Ames Laboratory is operated for the US Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. The STM/STS work is supported by NSF Grant No. DMR-1506618. A portion of this research used resources at Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. J.-G.C. is supported by the MOST, NSFC, and CAS (Grants No. 2018YFA0305700, No. 11574377, No. XDB25000000, and No. QYZDBSSW-SLH013). Work at ORNL and Ames Laboratory was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Ames Laboratory is operated for the US Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. The STM/STS work is supported by NSF Grant No. DMR-1506618. A portion of this research used resources at Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. J.-G.C. is supported by the MOST, NSFC, and CAS (Grants No. 2018YFA0305700, No. 11574377, No. XDB25000000, and No. QYZDBSSW-SLH013).
| Funders | Funder number |
|---|---|
| US Department of Energy | |
| National Science Foundation | 1506618 |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Iowa State University | |
| Division of Materials Sciences and Engineering | |
| College of Arts and Sciences, University of Nebraska-Lincoln | 2018YFA0305700, XDB25000000, 11574377 |
| National Natural Science Foundation of China | QYZDBSSW-SLH013 |
| Ministry of Science and Technology | |
| Norsk Sykepleierforbund | DMR-1506618 |