Magneto-Optical Properties of PtCu/Co Multilayers

The effect of Cu doping in Pt spacer layers on the magneto-optical properties of sputtered Pt/Co multilayers has been investigated. It was found that the polar Kerr rotation θ_k, ellipticity ε_k, refractive index n and absorptive index k show an oscillation behavior as a function of the Cu content x, reflective index R keeps almost constant with the decreasing wavelength λ, three θk peaks appear at x = 0.03, 0.12, 0.25, respectively. Values of conductivity tensor σ_1xx, σ_2xx, σ_1xy, and σ_2xy in the PtCu layers have been derived from experimental θ_k, ε_k, n, and k values at wavelength 770nm. The oscillation of the polar Kerr rotation θ_k may be resulted from spin polarized quantum size effects in the PtCu layers.