Abstract
Here we report the evolution of structural, magnetic, and transport properties in MnBi2-xSbxTe4(0≤x≤2) single crystals. MnSb2Te4, isostructural to MnBi2Te4, is successfully synthesized in single-crystal form. Magnetic measurements suggest an antiferromagnetic order below TN=19K for MnSb2Te4 with the magnetic moments aligned along the crystallographic c axis. With increasing Sb content in MnBi2-xSbxTe4, the a-lattice parameter decreases linearly following Vegard's law, while the c-lattice parameter shows little compositional dependence. The contraction along a is caused by the reduction of the Mn-Te-Mn bond angle, while the Mn-Te bond length remains nearly constant. The antiferromagnetic ordering temperature slightly decreases from 24 K for MnBi2Te4 to 19 K for MnSb2Te4. More dramatic change was observed for the critical magnetic fields required for the spin-flop transition and the moment saturation. Both critical fields decrease with increasing Sb content for x≤1.72; a spin-flip transition occurs in MnSb2Te4 at a small field of 3 kOe applied along the c axis. In high magnetic fields, the saturation moment at 2 K shows significant suppression from 3.56μB/Mn for MnBi2Te4 to 1.57μB/Mn for MnSb2Te4. Analysis of the magnetization data suggests that both the interlayer magnetic interaction and single-ion anisotropy decrease with increasing Sb content for x≤1.72. The partial substitution of Bi by Sb also dramatically affects the transport properties. A crossover from n-type to p-type conducting behavior is observed around x≈0.63. Our results show close correlation between structural, magnetic, and transport properties in MnBi2-xSbxTe4 and that partial substitution of Bi by Sb is an effective approach to fine tuning both the magnetism and transport properties of MnBi2-xSbxTe4.
| Original language | English |
|---|---|
| Article number | 104409 |
| Journal | Physical Review B |
| Volume | 100 |
| Issue number | 10 |
| DOIs | |
| State | Published - Sep 4 2019 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. This manuscript has been co-authored by employees of UT-Battelle, LLC under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Iowa State University | |
| Division of Materials Sciences and Engineering |