First-principles calculation of magnetic x-ray dichroism in Fe and Co multilayers

Guo, G. Y.; Ebert, H.; Temmerman, W. M.; Durham, P. J.

doi:10.1103/physrevb.50.3861

Cited by 128 publications

(64 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where I 75 XMLD is identical to the definition of magnetic linear dichroism of second class [67] when it is obtained at grazing incidence. The first term of expression (14) is the difference in the density of empty states between the direction near to normal to the sample and in the plane with the magnetic field applied in the transverse direction.…”

Section: Variation Of the Measured Neodymium Magnetic Momentmentioning

confidence: 95%

Perpendicular magnetic anisotropy in amorphous NdxCo1−x thin films studied by x-ray magnetic circular dichroism

et al. 2017

View full text Add to dashboard Cite

The origin of perpendicular magnetic anisotropy (PMA) in amorphous Nd x Co 1−x thin films is investigated using x-ray magnetic circular dichroism (XMCD) spectroscopy at the Co L 2,3 and Nd M 4,5 edges. The magnetic orbital and spin moments of the 3d cobalt and 4f neodymium electrons were measured as a function of the magnetic field orientation, neodymium concentration, and temperature. In all the studied samples, the magnetic anisotropy of the neodymium subnetwork is always oriented perpendicular to the plane, whereas the anisotropy of the orbital moment of cobalt is in the basal plane. The ratio L z /S z of the neodymium 4f orbitals changes with the sample orientation angle, being higher and closer to the atomic expected value at normal orientation and smaller at grazing angles. This result is well explained by assuming that the 4f orbital is distorted by the effect of an anisotropic crystal field when it is magnetized along its hard axis, clearly indicating that the 4f states are not rotationally invariant. The magnetic anisotropy energy associated to the neodymium subnetwork should be proportional to this distortion, which we demonstrate is accessible by applying the XMCD sum rules for the spin and intensity at the Nd M 4,5 edges. The analysis unveils a significant portion of neodymium atoms magnetically uncoupled to cobalt, i.e., paramagnetic, confirming the inhomogeneity of the films and the presence of a highly disordered neodymium rich phase already detected by extended x-ray-absorption fine structure (EXAFS) spectroscopy. The presence of these inhomogeneities is inherent to the evaporation preparation method when the chosen concentration in the alloy is far from its eutectic concentrations. An interesting consequence of the particular way in which cobalt and neodymium segregates in this system is the enhancement of the cobalt spin moment which reaches 1.95 μ B in the sample with the largest segregation.

show abstract

Section: Variation Of the Measured Neodymium Magnetic Momentmentioning

confidence: 95%

Perpendicular magnetic anisotropy in amorphous NdxCo1−x thin films studied by x-ray magnetic circular dichroism

et al. 2017

View full text Add to dashboard Cite

show abstract

“…46-49. A multiple-scattering approach to XMCD, a solid-state one-particle theory, has been proposed by Ebert et al [50][51][52] and Tamura et al [53].…”

Section: Electronic Structure and X-ray Magnetic Circular Dichroism Imentioning

confidence: 99%

Electronic structure and x-ray magnetic circular dichroism in uranium monochalcogenides

Antonov

Harmon

Andryushchenko

et al. 2004

Low Temperature Physics

View full text Add to dashboard Cite

The electronic structure and x-ray magnetic circular dichroism (XMCD) spectra of US, USe, and UTe are investigated theoretically from first principles, using the fully relativistic Dirac LMTO band structure method. The electronic structure is obtained with the local spin-density approximation (LSDA), as well as with a generalization of the LSDA+U method which takes into account that in the presence of spin-orbit coupling the occupation matrix of localized electrons becomes non-diagonal in spin indexes. The origin of the XMCD spectra in the compounds is examined.

show abstract

“…This effect is known as x-ray magnetic circular dichroism (XMCD), and it is widely used to determine element-specific magnetic moments by integrating the dichroic signals. [13][14][15][16] Differential evaluation even allows for extracting band structure information in complex intermetallic compounds. 17,18 In the case of magnetic circular dichroism in x-ray photoemission spectroscopy (MCDXPS), however, where electrons are excited into states far above the Fermi energy, the origin of the dichroic effect is not obvious.…”

Section: Introductionmentioning

confidence: 99%

Exchange coupling in the correlated electronic states of amorphous GdFe films

et al. 2013

View full text Add to dashboard Cite

The bulk sensitivity of hard x-ray photoelectron spectroscopy in combination with circularly polarized radiation of the P09 beamline at PETRA III enables the investigation of the magnetic properties of capped films. We have determined the temperature dependence of the magnetic circular dichroism in the Fe 2p and in the Gd 3d states in amorphous GdFe films. The magnetic dichroism reflects the stronger temperature dependence of Gd moments compared to Fe moments in agreement with mean-field models. We resolved the exchange split Gd 3d 5/2 substates and found a significant temperature dependence of the splitting which is attributed to a temperature dependent part of the exchange energy caused by Stoner-like itinerant states. A comparison of experimental and simulated x-ray photoemission spectra with corresponding data for x-ray absorption spectroscopy exciting the identical core holes clearly demonstrates that the core hole exchange interaction is the origin of the observed multiplet features for Gd.

show abstract

First-principles calculation of magnetic x-ray dichroism in Fe and Co multilayers

Cited by 128 publications

References 28 publications

Perpendicular magnetic anisotropy in amorphous NdxCo1−x thin films studied by x-ray magnetic circular dichroism

Perpendicular magnetic anisotropy in amorphous NdxCo1−x thin films studied by x-ray magnetic circular dichroism

Electronic structure and x-ray magnetic circular dichroism in uranium monochalcogenides

Exchange coupling in the correlated electronic states of amorphous GdFe films

Contact Info

Product

Resources

About