Magnetic and Magneto-Optical Properties of Co-(Pr, Nd) Artificial Superlattice

Artificial superlattices of Co-(Pr, Nd) were fabricated on glass substrates using electron beam evaporation. Magnetic properties such as (i) the temperature dependence of saturation magnetization M_s; (ii) the temperature dependence of the perpendicular magnetic anisotropy constant K⊥ and (iii) the wavelength dependence of the polar Kerr rotation angle θ_K were systematically investigated. For Co/Pr and Co/Nd artificial superlattices, rare earth atoms within 25 A of the interface were found to be coupled ferromagnetically with Co atoms at 77 K. The K⊥ increases with decreasing artificial period D, for both the Co/Pr and Co/Nd artificial superlattices. The maximum values of K⊥ at 77 K are 10×10⁶ erg/cm³ and 4×10⁶ erg/cm³ for Co/Pr and Co/Nd respectively. The wavelength at which the minimum θ_K is observed shifts from 0.45 μm to 0.65 μm with decreasing artificial period.