Evolution of magnetism in binary Fe-based semimetals: synthesis, low temperature properties and nuclear magnetic resonance studies

Selected Fe based semimetalic compounds like FeSi, FeSb2 and FeGa3 earned great attention because of their non magnetic ground state (driven by strong correlations) and their very good thermoelectric performance. The pure semimetals are already at the verge of magnetism and show signs of magnetic correlations at low temperatures [1,2]. Furthermore new materials like β-FeSi2 and CrSi2 are discussed in this context [3]. Metallic behavior and Fe-based magnetism could be introduced by controlled substitutions on the Fe or the framework site. The project combines the experience of the CPFS Chemical Metals Science department in the synthesis of highly pure single- and polycrystalline samples with the expertise of low temperature physics in the Quantum Material  department. Samples are characterized by thermal (specific heat), electronic (resistivity) and magnetic (susceptibility) bulk measurements in the temperature range from 0.35 K to 400 K and in fields up to 14 T. The bulk measurements are combined with nuclear magnetic resonance (above 2 K) on selected nuclei to probe the magnetism on a microscopic scale. NMR is a very powerful technique to sense magnetic correlations and it helps to disentangle between ferro- and anti- ferromagnetic contributions. For the applicant an experience on sample synthesis is not mandatory but skills in low temperature physics and solid state physics in general are recommended.


[1] A. A. Gippius et al. Appl. Magn. Reson. 45, 1237 (2014)

[2] A. A. Gippius et al. Phys. Rev. B 89, 104426 (2014)

[3] D. J. Singh, D. Parker, Sci. Rep. 3, 3517; DOI:10.1038/srep03517 (2013)

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