%0 Journal Article %1 SAHOO2023101265 %A Sahoo, M. %A Rahn, M.C. %A Kochetkova, E. %A Renier, O. %A Folkers, L.C. %A Tcakaev, A. %A Amigó, M.L. %A Stier, F.M. %A Pomjakushin, V. %A Srowik, K. %A Zabolotnyy, V.B. %A Weschke, E. %A Hinkov, V. %A Alfonsov, A. %A Kataev, V. %A Büchner, B. %A Wolter, A.U.B. %A Facio, J.I. %A Corredor, L.T. %A Isaeva, A. %D 2023 %J Mater. Today Phys. %K b %P 101265 %R https://doi.org/10.1016/j.mtphys.2023.101265 %T Tuning strategy for Curie-temperature enhancement in the van der Waals magnet Mn$_1+x$Sb$_2-x$Te$_4$ %U https://www.sciencedirect.com/science/article/pii/S2542529323003012 %V 38 %X 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.

@article{SAHOO2023101265, 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.}, added-at = {2023-11-16T18:31:55.000+0100}, author = {Sahoo, M. and Rahn, M.C. and Kochetkova, E. and Renier, O. and Folkers, L.C. and Tcakaev, A. and Amigó, M.L. and Stier, F.M. and Pomjakushin, V. and Srowik, K. and Zabolotnyy, V.B. and Weschke, E. and Hinkov, V. and Alfonsov, A. and Kataev, V. and Büchner, B. and Wolter, A.U.B. and Facio, J.I. and Corredor, L.T. and Isaeva, A.}, biburl = {https://www.bibsonomy.org/bibtex/278241e6875a0c986ceb975e5a5f3bd67/ctqmat}, day = 13, doi = {https://doi.org/10.1016/j.mtphys.2023.101265}, interhash = {6effc46d4798718b036a3b88739314ec}, intrahash = {78241e6875a0c986ceb975e5a5f3bd67}, issn = {2542-5293}, journal = {Mater. Today Phys.}, keywords = {b}, month = {11}, pages = 101265, timestamp = {2023-11-20T15:54:40.000+0100}, title = {Tuning strategy for Curie-temperature enhancement in the van der Waals magnet Mn$_{\mathbf{1+x}}$Sb$_{\mathbf{2-x}}$Te$_{\mathbf{4}}$}, url = {https://www.sciencedirect.com/science/article/pii/S2542529323003012}, volume = 38, year = 2023 }