TEP Seminar - Christoph Brüne

I will present our recent results on the epitaxial growth of antiferromagnetic thin films via molecular beam epitaxy. We have successfully developed the thin film growth for the antiferromagnetic Kagome materials FeSn and Mn₃Sn and for the antiferromagnetic semiconductor CuFeS₂.
Both FeSn and MnSn are antiferromagnets with a non-collinear spin structure arranging in the Kagome lattice. Kagome materials are of particular interest due to their frustrated spin texture and unconventional topological band structures and their non-trivial Magnon spectra. They are therefore candidate materials for Weyl nodes and host Dirac states in the band structure as well as in their magnon dispersion. Additionally, the magnetic properties support skyrmions up to elevated temperatures in these materials.
I will present our film growth and show that we have achieved single crystalline layer growth of both materials.

In addition to the Kagome materials we have also recently successfully synthesized single crystalline layers of the antiferromagnetic semiconductor CuFeS₂. CuFeS₂ has a high Néel temperature of approx. 820K and a lattice constant and lattice structure close to that of Si, making it an interesting material for spintronics applications. Moreover, the material crystallizes in the tetragonal  l-42d space group and is therefore a candidate d-wave altermagnet and additionally a potential host for antiferromagnetic skyrmions. We have successfully synthesized thin films on 001 Si substrates. I will show our current status for the molecular beam epitaxy growth of this material and it’s characterization.