Magnetic and magneto-optical properties of amorphous (Fe,Co)-(Pr,Nd) binary alloy films

Systematic experimental investigations have been made for the magnetic and magnetooptical properties of the amorphous (Fe,Co)-(Pr,Nd) binary alloy films prepared by electron beam evaporation technique. In Co-Nd amorphous alloy films, the maximum value of perpendicular magnetic anisotropy constant, , 6.2×10⁶erg/cm³at 77K was obtained for the film with 22 at% Nd content. In Fe-Nd amorphous alloy films, the maximum value of , 7.1×10⁶erg/cm³at 77K was found around 42at% Nd content. Polar Kerr rotation angle, θk, increases monotonically with increasing wavelength, λ, in Fe based amorphous alloy films. This dependence of θk on λ is similar to that for pure Fe film. While for Co based amorphous alloy films, the value of λ where θk exhibits a minimum shifts from 0.46μm in Co to 0.65μm in 30at% RE-Co with increasing rare earth content. The maximum value of θk obtained by present experiment is 0.26deg (λ=0.88μm) for the 22at% RE-Fe alloy, and 0.38deg (λ=0.4μm) for the 10at% RE-Co alloy. Change of the magneto-optical active transition induced by the magnetic moment arising from Pr and Nd is remarkable for the films with more than 15at% RE content.