Evolution of Magnetic Interactions in Sb-substituted MnBi2Te4

Abstract

The Mn(Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_4$ series is purported to span from antiferromagnetic (AF) topological insulator at x = 0 to a trivial AF insulator at x = 1. Here we report on neutron diffraction and inelastic neutron scattering studies of the magnetic interactions across this series. All compounds measured possess ferromagnetic (FM) triangular layers and we find a crossover from AF to FM interlayer coupling near x = 1 for our samples. The large spin gap at x = 0 closes rapidly and the average FM exchange interactions within the triangular layer increase with Sb substitution. Similar to a previous study of MnBi${}_2$Te${}_4$, we find severe spectral broadening which increases dramatically across the compositional series. In addition to broadening, we observe an additional sharp magnetic excitation in MnSb${}_2$Te${}_4$ that may indicate the development of local magnetic modes based on recent reports of antisite disorder between Mn and Sb sublattices. The results suggest that both substitutional and antisite disorder contribute substantially to the magnetism in Mn(Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_4$.

10 pages, 6 figures

References in corpus (5)

• Antiferromagnetic topological insulators
• Crystal growth and magnetic structure of MnBi2Te4
• Coexistence of Surface Ferromagnetism and Gapless Topological State in MnBi${}_2$Te${}_4$
• Interplay of Dirac electrons and magnetism in AMnBi2 (A=Ca, Sr)
• Determination of the exchange anisotropy in perovskite antiferromagnets using powder inelastic neutron scattering

Cited by in corpus (15)

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• Intrinsic magnetic topological insulators of the MnBi${}_2$Te${}_4$ family
• Ubiquitous order-disorder transition in the Mn antisite sublattice of the (MnBi${}_2$Te${}_4$)(Bi${}_2$Te${}_3$)${}_n$ magnetic topological insulators
• Ferroelectrically switchable magnetic multistates in MnBi${}_2$Te${}_4$(Bi${}_2$Te${}_3$)${}_n$ and MnSb${}_2$Te${}_4$(Sb${}_2$Te${}_3$)${}_n$ (n = 0, 1) thin films
• Role of Magnetic Defects and Defect-engineering of Magnetic Topological Insulators
• Magnon-magnon interaction in monolayer MnBi${}_2$Te${}_4$
• Magnetic-field-induced ab-plane rotation of the Eu magnetic moments in trigonal EuMg2Bi2 and EuMg2Sb2 single crystals below their Neel temperatures
• Quantum Effects at a Spin-Flop Transition in the Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$
• Infrared study of the layered, magnetic insulator Mn(Bi${}_{0.07}$Sb${}_{0.93}$)${}_2$Te${}_4$ at low temperatures
• Optical study of the charge dynamics evolution in the topological insulators MnBi${}_2$Te${}_4$ and Mn(Bi${}_{0.74}$Sb${}_{0.26}$)${}_2$Te${}_4$ under high pressure
• Realization of a three-dimensional quantum Hall effect in a Zeeman-induced second order topological insulator on a torus
• Evolution of the optical response of the magnetic topological insulators Mn(Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_4$ with Sb content
• Giant and Broadband Circular Dichroism from Particle-Hole Symmetry Breaking in Weyl Semimetals
• Hedgehog-like spin texture in Sb-doped MnBi${}_2$Te${}_4$
• Synthesis of intrinsic magnetic topological insulator MnBi2nTe3n+1 family by chemical vapor transport method with feedback regulation