The effect of interference on magneto-optics in magneto-optical layered structures

Abstract

Articles you may be interested inOptical and magneto-optical properties of Co-doped CeO2−δ films in the 0.5 to 4eV range In this article the magneto-optics of magneto-optical ͑M-O͒ layered structures have been studied theoretically and experimentally. For the air/M-O/air configuration, an analytic expression between the apparent complex Faraday rotation and the eigenvalue F ϭ e 1 F Ј can be obtained, when the M-O layers are semitransparent and weakly magnetic. The interference factor e 1 is a function of the optical constants and the M-O layer thickness d, and the light wavelength. In these structures, the apparent Faraday rotation consists of two parts. One oscillates as a function of the M-O layer thickness and the other is proportional to the layer thickness. The oscillation period and the amplitude are determined by the optical constants of the M-O layers. For the air/M-O/reflector configuration, the Kerr rotation k oscillates as a function of the M-O layer thickness and approaches a constant as the thickness d→ϱ. If the M-O layers are semitransparent and weakly magnetic, the apparent Kerr rotation can be expressed as k ϭ e 2 F Ј . For ultrathin metallic magnetic bilayered films the Kerr rotation is proportional to the M-O layer thickness and the enhancement factor is a function of the optical constants of the M-O layer and NM reflector. The magneto-optics of a Co spinel ferrite film, Co/Cu, Fe-Ni/Cu, and Co/Si structures have been studied experimentally.

Peculiar temperature dependence of magneto-optic Kerr rotation associated with antiferromagnetic–paramagnetic transition

“…21,22) According to the calculation, the photon energies for the peak and dip were determined by the refractive index (n) and thickness (t) of the Cr 2 O 3 layer; the oscillation behavior was scaled by n•t/λ. 13,14,16) More details about the virtual optical constant method and the calculation of the studied film were provided in previous works. 16,22) The parameters adopted in this study are listed in Appendix B and Table B.I.…”

“…12) The magneto-optic Kerr rotation angle (θ K ) and ellipticity in a stacked film are influenced by the interference of light in each layer. [13][14][15] This effect has been utilized to enhance the apparent θ K at a certain wavelength (λ) by including a transparent layer in a stacking structure. In this scheme, the optical parameters, i.e.…”

Magneto-optical studies of SrGa0.7 Co0.3 O3−δ perovskite thin films with embedded cobalt nanoparticles

“…There, the penetration depth exceeds the film thickness, which leads to strong magneto-optical interference (due to the multiple reflections inside the film and Faraday effect contribution to the measured signal). 19 Among the samples deposited on LSAT substrates, the 200 nm thick sample exhibits the highest amplitude of polar Kerr effect. With regards to the optical transparency of LSAT substrate in the investigated photon energy range, the enhancement in the magneto-optical interference can be attributed to the higher accumulation of Co nanoparticles at the substrate-film interface.…”

Temperature lag with the onset of exchange bias, superparamagnetic blocking, and antiferromagnetic ordering in ultrathin ferromagnet/antiferromagnet thin film

“…This effect has been widely used to enhance the apparent θ K in magneto-optic media. 27 As details on the optical interference effect on θ K are given in the Appendix, θ K is calculated using 28…”