EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Since the discovery of magnetic skyrmions in the B20 compound MnSi [1], there has been a significant interest in the magnetic properties of this and other B20 compounds. Many experimental and theoretical studies addressed the effect of transition metal doping and one of the interesting observations was the emergence of skyrmions in an alloy of non-magnetic FeSi and CoSi [2].

In this work, we study the magnetic phases and the underlying magnetic interactions in these systems doped with 3d, 4d and 5d transition metals. State-of-the-art theoretical method [3-5] based on density functional theory and dynamical mean-field theory is used to calculate accurately the microscopic picture of magnetic interactions, including the anisotropic Dzyaloshinskii-Moriya (DM) exchange, which can stabilize skyrmionic phases. The calculations reveal that the DM interaction is enhanced in 4d- and 5d-doped systems compared to the 3d-doped (Fe,Co)Si system. Micromagnetic simulations based on the first-principles magnetic parameters are performed under external field and indicate the presence of non-collinear magnetic textures. The structural stability of the studied compounds has been confirmed by the convex-hull calculations and our recent synthesis experiments.

1. S. Mühlbauer et al., Science 323, 915 (2009).

2. W. Münzer et al., PRB 81, 041203 (2010).

3. J. M. Wills, M. Alouani, P. Andersson, A. Delin, O. Eriksson, A. Grechnev, "Full-Potential Electronic Structure Method, Energy and Force Calculations with Density Functional and Dynamical Mean Field Theory'' (Springer Series in Solid-State Sciences, Volume 167, 2010), DOI 10.1007/978-3-642-15144-6.

4. Y. O. Kvashnin et al., PRB 102, 115162 (2020).

5. V. Borisov et al., arXiv:2011.08209.

This work was supported by the Knut and Alice Wallenberg Foundation and the Swedish National Infrastructure for Computing.