SEMPA investigation of the Dzyaloshinskii-Moriya interaction in the single, ideally grown Co/Pt(111) interface

Corredor, Edna C.; Kuhrau, Susanne; Kloodt-Twesten, Fabian; Frömter, Robert; Oepen, Hans Peter

doi:10.1103/physrevb.96.060410

Cited by 39 publications

(25 citation statements)

References 54 publications

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“…Using the above definitions, we find reasonable agreement between the different theoretical descriptions, and all parameters fall into the range where a ferromagnetic ground state is expected based on the experimental investigations in Ref. [45]. Figure 1 shows the calculated isotropic exchange constants J ij between the Co atoms as a function of interatomic distance for the different overlayers and for the uncapped system (no CL).…”

Section: Effective Interaction Parameterssupporting

confidence: 71%

Magnetism of a Co monolayer on Pt(111) capped by overlayers of 5d elements: A spin-model study

et al. 2018

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Using first-principles calculations, we study the magnetic properties of a Co monolayer on a Pt(111) surface with a capping monolayer of selected 5d elements (Re, Os, Ir, Pt and Au). First we determine the tensorial exchange interactions and magnetic anisotropies characterizing the Co monolayer for all considered systems. We find a close relationship between the magnetic moment of the Co atoms and the nearest-neighbor isotropic exchange interaction, which is attributed to the electronic hybridization between the Co and the capping layers, in spirit of the Stoner picture of ferromagnetism. The Dzyaloshinskii-Moriya interaction is decreased for all overlayers compared to the uncapped Co/Pt(111) system, while even the sign of the Dzyaloshinskii-Moriya interaction changes in case of the Ir overlayer. We conclude that the variation of the Dzyaloshinskii-Moriya interaction is well correlated with the change of the magnetic anisotropy energy and of the orbital moment anisotropy. The unique influence of the Ir overlayer on the Dzyaloshinskii-Moriya interaction is traced by scaling the strength of the spin-orbit coupling of the Ir atoms in Ir/Co/Pt(111) and by changing the Ir concentration in the Au1−xIrx/Co/Pt(111) system. Our spin dynamics simulations indicate that the magnetic ground state of Re/Co/Pt(111) thin film is a spin spiral with a tilted normal vector, while the other systems are ferromagnetic. arXiv:1801.09426v1 [cond-mat.mtrl-sci]

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Section: Effective Interaction Parameterssupporting

confidence: 71%

Magnetism of a Co monolayer on Pt(111) capped by overlayers of 5d elements: A spin-model study

et al. 2018

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“…Our calculated domain-wall width is in perfect agreement with the experimental value of about 4 nm in monolayer Co/Pt(111) as measured by spin-polarized scanning-tunneling microscopy (SP-STM) at low temperatures 64 . Very recently, a domainwall width of 17.2 nm in slightly thicker (1.4 nm) epitaxial Co layers on Pt(111) has been measured by SEMPA at room temperature 27 .…”

Section: Discussionmentioning

confidence: 99%

Comparison of first-principles methods to extract magnetic parameters in ultrathin films: Co/Pt(111)

et al. 2019

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We compare three distinct computational approaches based on first-principles calculations within density functional theory to explore the magnetic exchange and the Dzyaloshinskii-Moriya interactions (DMI) of a Co monolayer on Pt(111), namely (i) the method of infinitesimal rotations of magnetic moments based on the Korringa-Kohn-Rostoker (KKR) Green function method, (ii) the generalized Bloch theorem applied to spiraling magnetic structures and (iii) supercell calculations with non-collinear magnetic moments, the latter two being based on the full-potential linearized augmented plane wave (FLAPW) method. In particular, we show that the magnetic interaction parameters entering micromagnetic models describing the long-wavelength deviations from the ferromagnetic state might be different from those calculated for fast rotating magnetic structures, as they are obtained by using (necessarily rather small) supercell or large spin-spiral wave-vectors. In the micromagnetic limit, which we motivate to use by an analysis of the Fourier components of the domain-wall profile, we obtain consistent results for the spin stiffness and DMI spiralization using methods (i) and (ii). The calculated spin stiffness and Curie temperature determined by subsequent Monte Carlo simulations are considerably higher than estimated from the bulk properties of Co, a consequence of a significantly increased nearest-neighbor exchange interaction in the Co-monolayer (+50%). The calculated results are carefully compared with the literature.arXiv:1904.06954v1 [cond-mat.mtrl-sci]

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“…Following Ref. 27, we fit the domain-wall profile with a Gaussian distribution. This then allows us to estimate ∆ top when we have a value for the intrinsic SEMPA asymmetry A.…”

Section: Domain-wall Widthmentioning

confidence: 99%

Tuning Magnetic Chirality by Dipolar Interactions

et al. 2019

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The role of chirality is becoming more important for new applications in spintronics, especially in ultrathin magnetic films. [1][2][3][4][5][6] In magnetic racetrack applications for example, the chirality directly determines how magnetic domain walls and skyrmions interact with the spin-orbit torques. 2,3,7-10 It is therefore important to investigate the key contributing factors to this chirality. The underlying interaction that is believed to stabilize the chirality is the Dzyaloshinskii-Moriya interaction (DMI). As shown by a wealth of theoretical and experimental reports this interaction requires the breaking of inversion symmetry and originates from the interface between a heavy metal and a ferromagnet for the thin film systems investigated in this paper. 4,11 The DMI also helps to stabilize skyrmions because it favours non-collinear spin configurations, 12 which are envisaged to be used in areas ranging from magnetic racetrack memory and logic applications, to radio frequency devices and neuromorphic computing. 5,6Very recently, however, it was realized that DMI is not the only interaction that can stabilize a specific chirality. [8][9][10][13][14][15] Actually, already 40 years ago it was shown that the presence of dipolar fields leads to the formation of chiral Néel caps. 16,17 Here, the stray fields originating from magnetic domains align the spins inside the domain walls at the top of the film to form clockwise (CW) Néel walls and and at the bottom of the film to form counterclockwise (CCW) Néel walls, providing an optimized flux closure state. Dipolar interactions can often be ignored for the thin-film systems used for domain-wall studies.Because of the increase in magnetic volume and reduced coupling across the non-magnetic spacer layers this is no longer the case for the multilayer repeat systems often used to stabilize room-temperature magnetic skyrmions. [15][16][17][18][19] Both theoretical 8-10 and experimental work 8,13,14 suggests that in these multilayer repeat systems the DMI is in direct competition with the dipolar fields. Without DMI, the dipolar interactions introduce Néel caps. Including DMI, however, leads to a larger fraction of the layers being occupied by the Néel cap of the chirality favoured by the DMI. The other cap will be reduced in size and occupy fewer layers. This happens until the DMI is so large that it is no longer energetically favourable to accommodate a Néel cap not favoured by the DMI.The energetics and dynamics of both skyrmions and domain walls are affected by this competition because it determines the net chirality of the magnetic textures, which in turn influences the interaction with, for example, spin-orbit torques. 8-10 A fundamental understanding of this competition is therefore needed to properly tailor the interactions such that

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SEMPA investigation of the Dzyaloshinskii-Moriya interaction in the single, ideally grown Co/Pt(111) interface

Cited by 39 publications

References 54 publications

Magnetism of a Co monolayer on Pt(111) capped by overlayers of 5d elements: A spin-model study

Magnetism of a Co monolayer on Pt(111) capped by overlayers of 5d elements: A spin-model study

Comparison of first-principles methods to extract magnetic parameters in ultrathin films: Co/Pt(111)

Tuning Magnetic Chirality by Dipolar Interactions

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