Ab initio analysis of magnetic properties of prototype B20 chiral magnet FeGe

Abstract

FeGe in the B20 phase is an experimentally well-studied prototypical chiral magnet exhibiting helical spirals, skyrmion lattices and individual skyrmions with a robust length of 70~nm. While the helical spiral ground state can be verified by first-principles calculations based on density functional theory, this feature size could not be reproduced even approximately. To develop a coherent picture of the discrepancy between experiment and theory, we investigate in this work the magnetic properties of FeGe from first-principles using different electronic-structure methods. We study atomistic as well as micromagnetic parameters describing exchange and Dzyaloshinskii-Moriya interactions, and discuss their subtle dependence on computational, structural, and correlation parameters. In particular, we quantify how these magnetic properties are affected by changes of the lattice parameter, different atomic arrangements, exchange and correlation effects, finite Fermi-function broadening, and momentum-space sampling. In addition, we use the obtained atomistic parameters to determine the corresponding Curie temperature, which agrees well with experiments. Our results indicate that the well-known and well-accepted relation between the micromagnetic parameters and the period of the helical structure, is not valid for FeGe. This calls for new experiments exploring the relation by measuring independently the spin stiffness, the spiralization and the period of the helical spin spiral.

arXiv comment13 pages, 8 figures

References in corpus (39)

• Skyrmion Lattice in a Chiral Magnet
• Skyrmion Lattice in a Doped Semiconductor
• Unusual Hall Effect Anomaly in MnSi Under Pressure
• Experimental observation of magnetic bobbers for a new concept of magnetic solid-state memory
• Precursor phenomena at the magnetic ordering of the cubic helimagnet FeGe
• Skyrmions with varying size and helicity in composition-spread helimagnetic alloys
• Exchange interactions and temperature dependence of the magnetization in half--metallic Heusler alloys
• Antiskyrmions stabilized at interfaces by anisotropic Dzyaloshinskii-Moriya interaction
• New type of stable particle like states in chiral magnets (Chiral bobbers)
• Chiral skyrmions in cubic helimagnet films: the role of uniaxial anisotropy
• Real-space observation of short-period cubic lattice of skyrmions in MnGe
• Berry phase theory of Dzyaloshinskii-Moriya interaction and spin-orbit torques
• Exchange interaction parameters and adiabatic spin-wave spectra of ferromagnets: A "renormalized magnetic force theorem"
• Giant generic topological Hall resistivity of MnSi under pressure
• Doppler shift picture of the Dzyaloshinskii--Moriya interaction
• Dzyaloshinskii-Moriya interaction and Hall effects in the skyrmion phase of MnFeGe alloys
• First-principles prediction of high Curie temperature for ferromagnetic bcc-Co and bcc-FeCo alloys and its relevance to tunneling magnetoresistance
• Implications of the B20 Crystal Structure for the Magneto-electronic Structure of MnSi
• Scattering mechanisms in textured FeGe thin films: magnetoresistance and the anomalous Hall effect
• Chiral Bobbers and Skyrmions in Epitaxial FeGe/Si(111) Films
• Role of Dzyaloshinskii-Moriya interaction for magnetism in transition-metal chains at Pt step-edges
• Generic aspects of skyrmion lattices in chiral magnets
• Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe
• Helical magnetic structure and the anomalous and topological Hall effects in epitaxial B20 Fe${}_{1-y}$Co${}_y$Ge films
• Temperature and magnetic field dependence of the internal and lattice structures of skyrmions by off-axis electron holography
• First-order transition between a small-gap semiconductor and a ferromagnetic metal in the isoelectronic alloys FeSi${}_{1-x}$Ge${}_x$
• Mixed Weyl semimetals and dissipationless magnetization control in insulators by spin-orbit torques
• Dzyaloshinskii-Moriya interaction at disordered interfaces from ab initio theory: robustness against intermixing and tunability through dusting
• Exchange interactions and local moment fluctuation corrections in ferromagnets at finite temperatures based on non-collinear density-functional calculations
• First-Principles Evaluation of the Dzyaloshinskii--Moriya Interaction
• Weak antiferromagnetic ordering and pure magnetic reflections induced by Dzyaloshinskii-Moriya interaction in MnSi-type crystals
• Frustrated magnetic helices in MnSi-type crystals
• Hidden quantum phase transition in Mn${}_{1-x}$Fe${}_x$Ge: evidence brought by small-angle neutron scattering
• Exchange coupling in transition-metal nano-clusters on Cu(001) and Cu(111) surfaces
• Spin-wave dynamics in FeGe helimagnet: studied by small-angle neutron scattering
• Engineering Dzyaloshinskii-Moriya interaction in B20 thin film chiral magnets
• Higher-dimensional Wannier interpolation for the modern theory of the Dzyaloshinskii-Moriya interaction: Application to Co-based trilayers
• Composition-dependent magnetic response properties of Mn${}_{1-x}$Fe${}_x$Ge alloys
• Higher dimensional Wannier functions of multi-parameter Hamiltonians

Cited by in corpus (17)

• Topological-chiral magnetic interactions driven by emergent orbital magnetism
• Magnetic hedgehog lattices in noncentrosymmetric metals
• Curved Magnetism in CrI${}_3$
• Heisenberg and anisotropic exchange interactions in magnetic materials with correlated electronic structure and significant spin-orbit coupling
• Short period magnetization texture of B20-MnGe explained by thermally fluctuating local moments
• Microscopic Theory of Ultrafast Skyrmion Excitation by Light
• Micromagnetic description of twisted spin spirals in the B20 chiral magnet FeGe from first principles
• Robust metastable skyrmions with tunable size in the chiral magnet FePtMo${}_3$N
• Electronic and dynamical properties of cobalt monogermanide CoGe phases under pressure
• Tuning magnetic exchange interactions in 2D magnets: the case of CrGeX${}_3$ (X = Se, Te) and Janus Cr${}_2$Ge${}_2$(Se,Te)${}_3$ monolayers
• Experimental determination of the spin Hamiltonian of the cubic chiral magnet MnSi
• Helical spin dynamics in Cu${}_2$OSeO${}_3$ as measured with small-angle neutron scattering
• The influence of antiferromagnetic spin cantings on the magnetic helix pitch in cubic helimagnets
• Magnetoelectricity of Topological Solitons in 2D Magnets
• Origin of the suppression of magnetic order in MnSi under hydrostatic pressure
• General spin models from noncollinear spin density functional theory and spin-cluster expansion
• Non-collinear magnetism contra frustration: Magnetic order and anisotropy in hexagonal MnPtGa