Simulations and experiments on magneto-optical diffraction by an array of epitaxial Fe(001) microsquares

Abstract

Magneto-optic ͑MO͒ experimental and computational studies are reported on arrays of epitaxial Fe͑001͒ microsquares. Measuring the transverse Kerr signal, in both reflected and diffracted spots, when the array is exposed to a rotating magnetic field allows the quantification of the magnetization inhomogeneties within the microsquares. The MO signal at diffracted spots is extremely sensitive to magnetization inhomogeneities, while working at a large constant field amplitude eliminates uncertainties due to domain-wall movements. The presence of anomalous peaks at the diffracted MO response is unambiguously assigned to the matching of inhomogeneities of the magnetization distribution to the corresponding pattern periodicity. Interaction between microsquares appears as a second-order effect.

Diffractive magneto-optics, magnetic interactions, and reversal mechanisms inComicrosquare arrays

“…Magneto-optic techniques and, in particular, diffraction magneto-optic Kerr effect ͑DMOKE͒ are most suited to investigate experimentally such effects, since they show the high sensitivity needed to monitor magnetization changes in thin films and very small elements. We have previously shown also that DMOKE supplies valuable information also on the magnetization distribution 1 and anisotropy 2 due to its high sensitivity to magnetic inhomogeneities. This high sensitivity may provide the magnitude of the anisotropy constants, analyzing the array response on both the reflected and diffracted spots.…”

“…1,4,12 In this way, DMOKE effects can be modeled and interpreted using micromagnetic simulations combined with conventional optical diffraction theory.…”

Magnetic structure and diffracted magneto-optics of patterned amorphous multilayers

“…Diffracted MOKE magnetization loops, on the other hand, are proportional to the magnetic form factor f n m observed at the nth diffraction order of the scattered beam and can therefore yield information about the internal magnetization distribution of patterned elements in periodic arrays. [17][18][19][20][21][22][23][24] Furthermore, they can also be used to investigate and compare patterns from different arrangements of the same elements as is demonstrated in this study.…”

“…13,14 In this paper, we investigate the magnetic properties of patterned multilayers of ferromagnetic and nonmagnetic layers in a combined structure of circular and ellipsoidal islands with the magneto-optical Kerr effect ͑MOKE͒; by Kerr microscopy and specular and diffracted MOKE measurements. For this study we choose amorphous Co 68 Fe 24 Zr 8 for the ferromagnetic layer spaced with amorphous Al 2 O 3 , thick enough to remove any direct coupling between the magnetic layers. Amorphous materials are extremely interesting since they can be considered to be isotropic and exhibit good layer perfection.…”

Scattering theory formalism for the magneto-optics of nanocorrugated ferromagnet surfaces

“…3 Moreover, the magnetic character of the material induces a magnetic field dependence of the scattered light, which for the case of periodic arrays of ferromagnetic elements such as gratings, tiles, or dots has been used to analyze their magnetic properties. [4][5][6][7][8][9][10] In this work these studies are extended to analyze the magnetic response of nanocorrugated surfaces. First, a theoretical formalism needed to treat these corrugated surfaces is presented, paying special attention to the transverse Kerr configuration geometry.…”