Figure 3

(a) Magnetic field dependence of normalized Kerr ellipticity in polar configuration (P-MOKE curve) for Au/Co/Au nanostructure at two different incident wavelengths (λ): 500 nm (red line) and 750 nm (blue line). The insert is schematic of polar magneto-optical Kerr effect (P-MOKE) measurement configuration. Magnetic field (H) is applied perpendicular to the surface of the Au/Co/Au nanostructure. (b) P-MOKE curves of Au/Co/Au nanostructure at the negative magnetic field region. Red dashed lines is the fitted data for 500 nm and blue dashed lines is for 750 nm. Black dashed line is the saturation of Kerr ellipticity. The intersection of the black dashed line and the red or the blue dashed lines gives the saturation magnetic field. Black arrows indicate the saturation magnetic fields for λ = 500 nm (red circle) and 750 nm (blue circle).