Orbital magnetism in transition metal systems: The role of local correlation effects

Chadov, Stanislav; Minář, J.; Katsnelson, M. I.; Ebert, H.; Ködderitzsch, D.; Lichtenstein, A. I.

doi:10.1209/0295-5075/82/37001

Cited by 65 publications

(82 citation statements)

References 33 publications

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“…For Fe, the adopted U value is within the experimental value U ∼ 1 eV 32 and a value U ∼ 2 eV derived from theoretical studies. 68,69 In the case of Co and Ni the U values are in agreement with previous theoretical and experimental investigations. 24 Because the screening of the exchange interaction is usually small, the averaged on-site interaction J is generally accepted to coincide with its atomic value which is approximately equal to J ∼ 0.9 eV for all 3d elements and can be directly calculated.…”

Section: Resultssupporting

confidence: 90%

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Sánchez-Barriga

Braun²,

Minář³

et al. 2012

Phys. Rev. B

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We have investigated the spin-dependent quasiparticle lifetimes and the strength of electron correlation effects in the ferromagnetic 3d transition metals Fe, Co, and Ni by means of spin-and angle-resolved photoemission spectroscopy. The experimental data are accompanied by state-of-the-art many-body calculations within the dynamical mean-field theory and the three-body scattering approximation, including fully relativistic calculations of the photoemission process within the one-step model. Our quantitative analysis reveals that inclusion of local many-body Coulomb interactions are of ultimate importance for a realistic description of correlation effects in ferromagnetic 3d transition metals. However, we found that more sophisticated many-body calculations with larger modifications in the case of Fe and Co are still needed to improve the quantitative agreement between experiment and theory. In general, it turned out that not only the dispersion behavior of energetic structures should be affected by nonlocal correlations but also the line widths of most of the photoemission peaks are underestimated by the current theoretical approaches. The increasing values of the on-site Coulomb interaction parameter U and the band narrowing of majority spin states obtained when moving from Fe to Ni indicate that the effect of nonlocal correlations becomes weaker with increasing atomic number, whereas correlation effects tend to be stronger.

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Section: Resultssupporting

confidence: 90%

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Sánchez-Barriga

Braun²,

Minář³

et al. 2012

Phys. Rev. B

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“…The Hubbard U was set to 1.5 eV and 2.5 eV for Fe 2 B and Co 2 B, respectively, and the Hund's exchange J to 0.8 eV and 0.9 eV, respectively. These values of U are chosen since values in the range 1-3 eV are commonly used for metallic Fe and Co while using a somewhat larger value for Co than for Fe has been shown to yield a good description of the orbital magnetism in these elements [65]. The around mean field approximation was used for the double-counting correction.…”

Section: Electron Correlations In Fe 2 B and Co 2 B Within Dmftmentioning

confidence: 99%

Magnetic properties of(Fe1−xCox)2Balloys and the effect of doping by
Edström¹,
Werwiński²,
Iuşan³
et al. 2015
Phys. Rev. B

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We have explored, computationally and experimentally, the magnetic properties of (Fe 1−x Co x ) 2 B alloys. Calculations provide a good agreement with experiment in terms of the saturation magnetization and the magnetocrystalline anisotropy energy with some difficulty in describing Co 2 B, for which it is found that both full potential effects and electron correlations treated within dynamical mean field theory are of importance for a correct description. The material exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations between x = 0.1 and x = 0.5. A simple model for the temperature dependence of magnetic anisotropy suggests that the complicated nonmonotonic behavior is mainly due to variations in the band structure as the exchange splitting is reduced by temperature. Using density functional theory based calculations we have explored the effect of substitutionally doping the transition metal sublattice by the whole range of 5d transition metals and found that doping by Re or W elements should significantly enhance the magnetocrystalline anisotropy energy. Experimentally, W doping did not succeed in enhancing the magnetic anisotropy due to formation of other phases. On the other hand, doping by Ir and Re was successful and resulted in magnetic anisotropies that are in agreement with theoretical predictions. In particular, doping by 2.5 at. % of Re on the Fe/Co site shows a magnetocrystalline anisotropy energy which is increased by 50% compared to its parent (Fe 0.7 Co 0.3 ) 2 B compound, making this system interesting, for example, in the context of permanent magnet replacement materials or in other areas where a large magnetic anisotropy is of importance.

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“…Nevertheless, the variation should be small, i.e., see Ref. [33] for cobalt, thus, we do not expect that this difference influences our results significantly. The on-site uniaxial magnetic anisotropies used in this work are k u (Co) = 3.73 × 10 −23 J/atom and k u (Tb) = 2.16 × 10 −22 J/atom.…”

Section: Modelmentioning

confidence: 78%

“…To model the properties of TbCo we have used the following material parameters: damping constant λ = 0.05 for both materials, and magnetic moments μ Co = 1.61μ B [33] and μ Tb = 9.34μ B [34]. The selected magnetic moment values for our simulations are the corresponding bulk values for Co and Tb.…”

Section: Modelmentioning

confidence: 99%

Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo

et al. 2017

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Orbital magnetism in transition metal systems: The role of local correlation effects

Cited by 65 publications

References 33 publications

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Magnetic properties of(Fe1−xCox)2Balloys and the effect of doping by
Edström¹,
Werwiński²,
Iuşan³
et al. 2015
Phys. Rev. B

Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo

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Orbital magnetism in transition metal systems: The role of local correlation effects

Cited by 65 publications

References 33 publications

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Effects of spin-dependent quasiparticle renormalization in Fe, Co, and Ni photoemission spectra:An experimental and theoretical study

Magnetic properties of(Fe1−xCox)2Balloys and the effect of doping byEdström1, Werwiński2, Iuşan3 et al. 2015Phys. Rev. B

Conditions for thermally induced all-optical switching in ferrimagnetic alloys: Modeling of TbCo

Contact Info

Product

Resources

About

Magnetic properties of(Fe1−xCox)2Balloys and the effect of doping by
Edström¹,
Werwiński²,
Iuşan³
et al. 2015
Phys. Rev. B