Berlin 2018 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 4: Skyrmions I (joint session MA/KFM/TT)

KFM 4.11: Vortrag

Montag, 12. März 2018, 18:00–18:15, EB 301

Giant structural response of Dzyaloshinskii-Moriya interaction in MnGe B20 compounds — •Sergii Grytsiuk, Marcel Bornemann, Markus Hoffmann, Bernd Zimmermann, Phivos Mavropoulos, Gustav Bihlmayer, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Non-centrosymmetric cubic B20 materials are currently under intensive investigation. An important feature of these materials is the competition between the antisymmetric Dzyaloshinskii-Moriya interaction (DMI) and the symmetric exchange interaction resulting in a rich variety of magnetic phases with respect to temperature, magnetic fields, material compositions and geometries. The possibility of engineering chiral structures and the effective switching between different magnetic phases requires the investigation of possible factors that influence the strength of the magnetic interactions. In this work, we show by first-principles calculations based on DFT that under pressure magnetic and structural properties of MnGe reveal a hysteretic behavior near the state where energies of high and low spin states coincide. We observe that pressure strongly enhances the DMI (by a factor 5), while the spin-stiffness gets smaller. In order to understand such giant enhancement of the micromagnetic DMI we computed atomistic DMI vectors. Surprisingly, the absolute value of the DMI vectors do not depend significantly on the lattice parameter and the enhancement of micromagnetic DMI stems mainly from the change of the DMI vectors’ orientation with respect to bonds between Mn atoms.