Relation between<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>,</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>XMCD and the magnetic ground-state properties for the early<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>3</mml:mn><mml:mi>d</mml:mi></mml:math>element V

We present a detailed study on the morphology and magnetic properties of Co nanostructures deposited onto oxidized Si substrates by femtosecond pulsed laser deposition. Generally, Co disks of nanometric dimensions are obtained just above the ablation threshold, with a size distribution characterized by an increasingly larger number of disks as their size diminishes, and with a maximum disk size that depends on the laser power density. In Au/Co/Au structures, in-plane magnetic anisotropy is observed in all cases, with no indication of superparamagnetism regardless of the amount of material or the laser power density. Magnetic force microscopy observations show coexistence of single-domain and vortex states for the magnetic domain structure of the disks. Superconducting quantum interference device magnetometry and x-ray magnetic circular dichroism measurements point to saturation magnetization values lower than the bulk, probably due to partial oxidation of the Co resulting from incomplete coverage by the Au capping layer.

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“…Theoretical results 49 indicate that 7T z / S Ͻ 0.1, hence giving an error in S of up to 10% by neglecting T z .…”

Section: Xmcdmentioning

confidence: 99%

Growth and magnetic characterization of Co nanoparticles obtained by femtosecond pulsed laser deposition

Cebollada

Martin²,

Clavero³

et al. 2009

Phys. Rev. B

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“…Theoretical results 63 indicate that 7T z / S Ͻ 0.1, so that neglecting T z gives an error in S up to 10%. Here, we have extracted the Co magnetic moments by assuming that T z =0 and that the mixing of the 2p 3/2 and 2p 1/2 core levels as well as transitions to the sp valence band states can be neglected in the L 2,3 XMCD spectrum.…”

Section: Atomic Magnetic Moments: Effect Of V Atomic Volumementioning

confidence: 99%

Interface effects, magnetic, and magneto-optical properties ofAl∕Co∕V∕MgO(100)structures

Huttel

Clavero²,

Laan

et al. 2008

Phys. Rev. B

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The magnetic and magneto-optical properties of Al/ Co/ V / MgO͑100͒ structures and the influence of the Co/ V interface for different thicknesses of the Co and V layers have been studied experimentally. From the element-specific hysteresis loops obtained by x-ray magnetic circular dichroism ͑XMCD͒ at the Co and V L 3 edges we find that the V layers are magnetically polarized antiparallel to the Co layers and that magnetization reversal occurs at the same magnetic field in both layers. The effect of the V atomic volume and the relative thicknesses of V and Co layers on the magnetic moments of the V and Co atoms are also studied. Contrary to what might be expected, the atomic magnetic moments of the V and Co atoms do not depend on the V atomic volume, however they depend strongly on the thicknesses of the V and Co layers. From the trend in the Co and V atomic magnetic moments as a function of Co and V thicknesses and the absence of any spectroscopic evidence for the formation of a VCo alloy, a long-range spin polarization of the V atoms is proposed. The extracted magneto-optical ͑MO͒ constants of V and Co as a function of photon energy clearly evidence a large amount of polarization in the V films in agreement with the XMCD results, which is indicative of the magnetic coupling between Co and V. The experimental MO results and simulations also show the strong influence of these polarized V layers in the MO properties of the complete system. These results, given the absence of spectroscopic evidence for the formation of a VCo alloy, support a long-range magnetization of the V atoms and a reduction of the Co atomic magnetic moments.

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“…For CrO 2 the analysis of the XMCD spectra of the L 2 and L 3 edges of the Cr atom ͑corresponding to the 2p 1/2 →3d and 2p 3/2 →3d transitions͒ is more difficult because the spin-orbit coupling of the Cr 2p electrons is relatively weak so that the 2p 1/2 and 2 p 3/2 levels are not well separated. 15 The subdivision of the XMCD spectra into the L 2 and L 3 contributions ͑which is required for an application of the spin sum rule͒ is therefore highly problematic due to a possible quantum-mechanical mixture of the 2p 1/2 and 2p 3/2 levels and/or due to a strong overlap of the two contributions on the energy scale. In their original analysis Goering et al 3 neglected the quantummechanical mixture.…”

mentioning

confidence: 99%

Anisotropy of orbital moments and magnetic dipole termTzinCrO2:An
Komelj
¹
,
Ederer
²
,
Fähnle³
2004
Phys. Rev. B
14
7
6
0
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A systematic study is performed by the ab initio density-functional theory of the anisotropy of the orbital moments ͗l z ͘ and the magnetic dipole term ͗T z ͘ in bulk CrO 2 . Two different band-structure techniques are used ͑full potential linearized-augmented-plane-wave method and linear-muffin-tin-orbital method in the atomic-sphere approximation͒, and the electronic correlations are treated by the local-spin-density approximation ͑LSDA͒, the LSDAϩ orbital polarization method, and the LSDAϩU method. The calculated anisotropies of ͗l z ͘ and ͗T z ͘ are very large compared to Fe, Ni, and Co but still a factor of 5 and 2 smaller than the anisotropies obtained from a recently suggested analysis of the x-ray magnetic circular dichroism spectra for a thick layer of CrO 2 . DOI: 10.1103/PhysRevB.69.132409 PACS number͑s͒: 75.30.Gw, 71.15.Mb Recent research within the fields of magnetic tunneling and spin injection involves CrO 2 as a promising material for electrodes.1 Besides its potential importance for applications, this material also exhibits interesting physics originating from its half metallic nature and consequently the ferromagnetism due to the double-exchange coupling, 2 as well as from its orbital magnetism 3,4 which is related to the spinorbit coupling and the electronic orbital correlation effects. Consequently, there are already several experimental 3,4 and theoretical 4 -7 investigations of the orbital moments ͗l z ͘ in CrO 2 .However, much less information is available on the anisotropy of the orbital moments, i.e., on its dependence of the orientation of the sample magnetization ͑in the following the z axis of the external coordinate system is always chosen to be parallel to the magnetization direction͒. It has been pointed out first by Bruno 8 and later worked out in more detail by van der Laan 9 that the anisotropy of the orbital moment is closely related to the magnetocrystalline anisotropy energy. Furthermore, van der Laan has shown that there is an additional contribution to the anisotropy energy arising from the anisotropy of the magnetic dipole term T z , which is the expectation value of the magnetic dipole operator:In Eq. ͑1͒ r is the unit vector in the direction of the position vector r and is the vector of the Pauli matrices. In fact, it turns out ͑see below͒ that for CrO 2 the two contributions are very large and of similar magnitudes but opposite in sign.A suitable method to investigate the anisotropy of ͗l z ͘ and ͗T z ͘ is the angle-resolved variant 10 of the x-ray magnetic circular dichroism 11 ͑XMCD͒ which measures the XMCD spectra for various orientations of the sample magnetization.The orbital moments ͗l z ͘ then may be determined directly from the application of the XMCD orbital sum rule.12 In contrast, the application of the spin sum rule 13 yields a combination of the spin moment ͗ z ͘ and the ͗T z ͘ term. A separation of these two contributions is possible by applying the spin sum rule to XMCD spectra for various orientations of the sample magnetization. Cr atom in a thick l...

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Relation betweenL2,3XMCD and the magnetic ground-state properties for the early3delement V

Cited by 54 publications

References 32 publications

Growth and magnetic characterization of Co nanoparticles obtained by femtosecond pulsed laser deposition

Growth and magnetic characterization of Co nanoparticles obtained by femtosecond pulsed laser deposition

Interface effects, magnetic, and magneto-optical properties ofAl∕Co∕V∕MgO(100)structures

Anisotropy of orbital moments and magnetic dipole termTzinCrO2:An
Komelj
¹
,
Ederer
²
,
Fähnle³
2004
Phys. Rev. B
14
7
6
0
View full text Add to dashboard Cite

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Relation betweenL2,3XMCD and the magnetic ground-state properties for the early3delement V

Cited by 54 publications

References 32 publications

Growth and magnetic characterization of Co nanoparticles obtained by femtosecond pulsed laser deposition

Growth and magnetic characterization of Co nanoparticles obtained by femtosecond pulsed laser deposition

Interface effects, magnetic, and magneto-optical properties ofAl∕Co∕V∕MgO(100)structures

Anisotropy of orbital moments and magnetic dipole termTzinCrO2:AnKomelj1, Ederer2, Fähnle3 2004Phys. Rev. B14760View full textAdd to dashboardCite

Contact Info

Product

Resources

About

Anisotropy of orbital moments and magnetic dipole termTzinCrO2:An
Komelj
¹
,
Ederer
²
,
Fähnle³
2004
Phys. Rev. B
14
7
6
0
View full text Add to dashboard Cite