Magneto-optical spectra of Fe/Au artificial superlattices modulated by integer and noninteger atomic layers

Abstract

Spectra of the magneto-optical Kerr effect, in a series of ͓Fe (xML͒/Au (xML)͔ N superlattices with integer and noninteger values of x (1рxр15), were measured. For xϭ1 the superlattic forms an L1 0 -type ordered alloy structure. The magneto-optical spectrum of the superlattice exhibits a prominent structure around 4 eV, which shows a systematic shift toward higher energies as x increases (1рxр5). No such structure can be reproduced by an optical calculation assuming a simple stack of thin Fe and Au layers. Ab initio band calculations have shown similar magneto-optical spectra and a similar peak shift with an increase in x (1рxр6). This suggests that electronic structures which differ from that of a simple stack of thin Fe and Au are realized in the superlattices. For noninteger values of x, oscillatory behavior with a period of one monolayer was observed in the low energy region of the magneto-optical spectra.

Anisotropic magnetization-induced second harmonic generation in Fe/Au superlattices

“…18 Formation of superlattice structure was confirmed by x-ray diffraction as described in detail in Ref. 16.…”

“…16 They were prepared on MgO ͑100͒ substrates by an ultrahigh vacuum ͑UHV͒ deposition technique. The base pressure of the deposition system was 3ϫ10 Ϫ10 Torr.…”

“…14 The linear magneto-optical spectra of the superlattices modulated by integer and non-integer numbers of atomic layers have been studied intensively, suggesting the formation of a peculiar band structure in such an artificial real-space structure. 15,16 Strong second harmonic ͑SH͒ signals were observed from the Fe/Au superlattices that showed clear fourfold anisotropy in the azimuthal dependence of SH intensity and the magnetization-induced effect, which demonstrates a high long-range in-plane order in the superstructures. The azimuthal dependence of the nonlinear magneto-optical Kerr rotation has also been studied.…”

Femtosecond resonant magneto-optical Kerr effect measurement on an ultrathin magnetic film in a soft X-ray free electron laser

“…In the bulk bcc iron, the hole number of the 3d states is 3.39, 17) on the other hand, in the ultrathin iron film, it is not well defined. The Fe 3d states hybridize with Au sp bands and 5f states at the interface between Fe and Au(001), 18,19) which results in the modification of the filling of Fe 3d states. The magnetic moments per hole were estimated to be m eff spin =n h ¼ 0:629 μ B =hole and m orb =n h = 0.0500 μ B =hole.…”

Optical and Magnetooptical Spectroscopy of the Nanostructural Multilayered Films: Possible Applications

“…The MO properties of the Co/Pt [1][2][3][4][5][6] and Fe/Au [7][8][9][10][11][12][13] MLF have been widely investigated experimentally and theoretically. The experimentally observed unusual MO response is attributed to the direct orbital hybridization between Pt(Au) and Co(Fe) atoms: the spin magnetization of the magnetic Fe(Co) atoms is transferred to the nonmagnetic Pt(Au) atoms and the stronger spin-orbit coupling of the heavy Pt(Au) atoms is transmitted to the Fe(Co) atoms [14].…”