Publication Date

9-1-2019

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Physics and Astronomy, Ames Laboratory

OSTI ID+

1561643

Report Number

IS-J 10040

DOI

10.1103/PhysRevB.100.104409

Journal Title

Physical Review B

Volume Number

100

Issue Number

10

First Page

104409

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.

DOE Contract Number(s)

AC05-00OR22725; AC0500OR22725; AC02-07CH11358

Language

en

Department of Energy Subject Categories

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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