Tuning strategy for Curie-temperature enhancement in the van der Waals magnet Mn1+xSb2−xTe4

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • M. Sahoo - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • M. C. Rahn - , Chair of Physics of Quantum Materials (Author)
  • E. Kochetkova - , Leibniz Institute for Solid State and Materials Research Dresden, University of Amsterdam (Author)
  • O. Renier - , University of Amsterdam (Author)
  • L. C. Folkers - , Junior Professorship in Synthesis and Crystal Growth of Quantum Materials (Author)
  • A. Tcakaev - , Würzburg-Dresden Cluster of Excellence ct.qmat, University of Würzburg (Author)
  • M. L. Amigó - , Leibniz Institute for Solid State and Materials Research Dresden, Comisión Nacional de Energía Atómica (Author)
  • F. M. Stier - , Chair of Physics of Quantum Materials (Author)
  • V. Pomjakushin - , Paul Scherrer Institute (Author)
  • K. Srowik - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • V. B. Zabolotnyy - , University of Würzburg (Author)
  • E. Weschke - , Helmholtz Centre Berlin for Materials and Energy (Author)
  • V. Hinkov - , Würzburg-Dresden Cluster of Excellence ct.qmat, University of Würzburg (Author)
  • A. Alfonsov - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • V. Kataev - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • B. Büchner - , Clusters of Excellence ct.qmat: Complexity and Topology in Quantum Matter, Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • A. U.B. Wolter - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • J. I. Facio - , Comisión Nacional de Energía Atómica (Author)
  • L. T. Corredor - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • A. Isaeva - , Leibniz Institute for Solid State and Materials Research Dresden, University of Amsterdam (Author)

Abstract

The van-der-Waals antiferromagnetic topological insulator MnBi2Te4 is one of the few materials that realize the sought-after quantum anomalous Hall (QAH) state and quantized surface charge transport. To assess the relevance of its isostructural analog MnSb2Te4 as a potential QAH candidate, the roles of Mn/Sb site mixing and cationic vacancies need to be clarified. Recent findings have shown that non-stoichiometry in Mn1±xSb2∓xTe4 is an efficient tuning knob to achieve a net spin-polarized state and to raise the magnetic ordering temperature well above that of MnBi2Te4. Here, we report the crystal structure, the bulk and the surface magnetism of two new Mn1+xSb2−xTe4 samples: Mn1.08Sb1.92Te4(x ≈ 0.1) with TC = 44 K, and Mn2.01Sb1.19Te4(x ≈ 1.0) with the record TC = 58 K. We quantify the site mixing comprehensively by combining various structural probes on powders and single crystals, and then employ bulk, local (electron spin resonance), and spectroscopic (x-ray magnetic circular dichroism) probes to connect these insights to the magnetism of these materials. We demonstrate that Mn over-stoichiometry up to x = 1.0, in combination with a particular Mn/Sb intermixing pattern and the increasingly three-dimensional character of the magnetic order, push the TC upwards. The tendency towards more robust ferromagnetism mediated by stronger interlayer exchange in Mn1+xSb2−xTe4 upon increasing x is confirmed by bulk magnetometry and by a series of density-functional-theory calculations of model structures with varying intermixing.

Details

Original languageEnglish
Article number101265
JournalMaterials today physics
Volume38
Publication statusPublished - Nov 2023
Peer-reviewedYes