Giant magneto-optical anisotropy in Fe/Au monoatomic multilayer

Abstract A giant magneto-optical anisotropy (MOA) in a magnetic monoatomic Fe/Au multilayer structure is reported. The dependence of the off-diagonal part of the optical conductivity tensor on the angle between the magnetization and crystallographic axes is evidenced by measurements of both the polar and longitudinal Kerr effects. The microscopic origin of the MOA is elucidated on the basis of the first principles' band-structure calculations. A relationship of the MOA with the predicted strong anisotropy of Fe d orbital magnetic moment and the magnetocrystalline anisotropy is discussed.

Layer-resolved optical conductivity of magnetic multilayers

The concept of the layer-resolved optical conductivity $^{IJ}(\omega)$ applied by means of a conventional band structure method is introduced. It is demonstrated that it allows for a detailed discussion of the magneto-optical properties of magnetic multilayer systems. In particular it is found that the layer-projected optical conductivity $^{I}(\omega)$ of an atomic layer is influenced by only very few neighboring layers. This property can be exploited within the Baukasten principle that aims to predict the magneto-optical properties of a complex layer system from the properties calculated for a closely related but simpler one

Microscopic origin of the magnetocrystalline anisotropy energy of ferromagnetic-semiconductor multilayers


Results of a detailed study of the spin-orbit–induced electronic 
magnetocrystalline anisotropy energy (MAE) of Fe/GaAs (001) 
ferromagnetic-semiconductor multilayers using the first-principles 
spin-polarized relativistic (SPR) linear-muffin-tin-orbital (LMTO) 
method are presented. For a further analysis, the spin-orbit–induced 
orbital moments have been calculated in a spin-resolved way, in addition. 
This allowed to check the relationship between the MAE and the orbital 
moments suggested by Bruno and van der Laan. According to that 
relationship, the microscopic origin of the electronic MAE of these 
multilayers is mainly due (~ 80%) to a delicate rearrangement 
of the occupations of certain 3d minority spin levels at the interface 
Fe layers.

Magneto-optical spectroscopy of magnetic multilayers: Theory and experiment (A review)

Experimental and theoretical results on the optical and magneto-optical (MO) spectral properties of a series of Co/Cu, Co/Pd, Co/Pt and Fe/Au multilayers (MLS) are reviewed. Diagonal and off-diagonal components of the optical conductivity tensor have been determined in the photon energy range 0.8-5.5 eV from the polar and longitudinal Kerr rotation as well as ellipticity and the ellipsometry measurements. The conductivity tensor has been evaluated on the basis of self-consistent spin-polarized relativistic linear muffintin orbital (LMTO) band-structure calculations within the local spin-density approximation. The role of the spin polarization and the spin-orbit interaction in the formation of the magneto-optical Kerr effect (MOKE) spectra as inferred from first-principles calculations is examined and discussed. The high sensitivity of the MO properties to the interface structure is studied by ab initio modeling of the effects of the interface alloying, substitutional disorder, and the roughness at the interfaces. It is shown that the MOKE spectra of the MLS calculated using the LMTO method reproduce the experimental spectra only moderately well if ideal multilayer structure with sharp interfaces are assumed. It is shown that the MOKE spectra of the MLS can be adequately reproduced only by taking into account their real interface microstructure. The magneto-optical anisotropy (MOA) is studied both experimentally and theoretically for a series of Fen/Aun superlattices prepared by molecular beam epitaxy with n=1,2,3 of Fe and Au atomic planes of (001)orientation. The results of the LMTO calculations show that the microscopic origin of the large MOA is the interplay of the strong spin- orbit coupling on Au sites and the large exchange splitting on Fe sites via Au d-Fe d hybridization of the electronic states at the interfaces. The orientation anisotropy of the d orbital moment is calculated from first principles and analyzed on the basis of d orbital symmetry considerations. The relationship between the orbital moment anisotropy and the MOA is discussed. The reviewed results imply that the magneto-optical properties of multilayers with various compositions and structures can be quantitatively predicted from first-principles band-structure calculations. Such a possibility is important for basic research as well aplications. Experimental and theoretical results on the optical and magnetooptical (MO) spectral properties of a series of Co/Cu, Co/Pd, Co/Pt and Fe/Au multilayers are reviewed. Diagonal and off-diagonal components of the optical conductivity tensor have been determined in the photon energy range 0.8-5.5 eV from the polar and longitudinal Kerr rotation as well as ellipticity and ellipsometry measurements. The conductivity tensor has been evaluated on the basis of self-consistent spin-polarized relativistic linear muffin-tin orbital (LMTO) band-structure calculations within the local spin-density approximation. The role of the spin polarization and the spin–orbit interaction in the formation of the magnetooptical Kerr effect (MOKE) spectra as inferred from first-principles calculations is examined and discussed. The high sensitivity of the MO properties to the interface structure is studied by ab initio modeling of the effects of the interfacial alloying, substitutional disorder, and the roughness at the interfaces. It is shown that the MOKE spectra of the multilayered structures (MLS) calculated using the LMTO method reproduce the experimental spectra only moderately well if ideal MLS with sharp interfaces are assumed. It is shown that the MOKE spectra of the MLS can be adequately reproduced only by taking into account their real interface microstructure. The magnetooptical anisotropy (MOA) is studied both experimentally and theoretically for a series of Fen/Aun superlattices prepared by molecular beam epitaxy with n=1,2,3 Fe and Au atomic planes of (001) orientation. The results of the LMTO calculations show that the microscopic origin of the large MOA is the interplay of the strong spin-orbit coupling on Au sites and the large exchange splitting on Fe sites via Aud–Fe d hybridization of the electronic states at the interfaces. The orientation anisotropy of the d orbital moment is calculated from first principles and analyzed on the basis of d orbital symmetry considerations. The relationship between the orbital moment anisotropy and the MOA is discussed. The reviewed results imply that the magnetooptical properties of multilayers with various compositions and structures can be quantitatively predicted from first-principles band-structure calculations. Such a possibility is important for basic research as well as applications

On the nature of the absolute maximal observable magneto-optical Kerr rotation of CeSb

We report first-principles calculations of the polar magneto-optical (MO) Kerr spectra of the Ce compounds CeSb, $\rm CeSb _{0.75} Te _{0.25}$, CeTe, and CeSe, using the local-density approximation (LDA) of density-functional theory as well as its generalization which contains an explicit Coulomb interaction U (LDA+U). Although the LDA predicts a large Kerr rotation of about 20$^{\circ}$ in CeSb, we find that the LDA+U gives a better description of the Kerr spectra of all four compounds. For CeSb the LDA+U predicts a colossal Kerr rotation of 45$^{\circ}$ up to 60$^{\circ}$, in agreement with the recent discovery of the maximal observable rotation of 90$^{\circ}$ in CeSb by Pittini et al. (Phys. Rev. Lett., 77 (1996) 944). The origin of the colossal Kerr rotation realized in CeSb is examined

Electronic structure and optical spectra of LuInCu4 and YbMCu4 (M=Cu, Ag, Au, Pd, and In)

Optical reflectivity measurements over a wide spectral range and at different temperatures together with self-consistent electronic band structure calculations have been used to investigate the electronic structure of the LuInCu4 and YbMCu4 (M = Cu,Ag,Au,Pd,In) compounds. The electronic structure of the compounds is investigated theoretically using an energy-band approach in combination with the linear-response formalism. The energy-hand structure is obtained within the local-spin-density approximation (LSDA) and within its extension that explicitly takes into account the on-site 4f Coulomb interaction Lr (LSDA + U). A remarkable agreement between theory and experiment has been found