Magnetic and magneto-optical properties of Co-(Pr, Nd) amorphous evaporated films.

Abstract

Co based amorphous binary alloy films. Co100-xRx (10≤x≤55, R=Pr, Nd) were prepared on glass substrates using the electron beam evaporation technique. From magnetic and magneto-optical viewpoints, systematic experimental investigations were carried out on these films. As a result, (i) the dependence of perpendicular magnetic anisotropy constant with the correction of 2πMs2, K⊥, on temperature and composition, and (ii) the dependence of polar Kerr rotatiom angle, θK, on wavelength, λ (0.4∼1.1μm) and composition were systematically clarified. A maximum value of K⊥ of about 6 × 106 erg/cm3 at 77 K was obtained for Co-Nd amorphous film with 25 at% Nd concentration. K⊥ decreases monotonically with increasing temperature and becomes zero around 400 K. This temperature at which K⊥ disappeared was nearly the same for all the films examined regardless of alloy composition. A maximum value of θK, 0.38 deg (λ=0.4μm) in the present amorphous films was obtained at about 11 at% Nd concentration. The peak at which the minimum value of θK is observed shifts from 0.46μm (Co) to 0.65μm (31 at% Pr, Nd) in wavelength with increasing Pr, Nd concentration. Change of the magneto-optical active transition induced by the existence of Pr and Nd atom was found to be remarkable around at 30 at% rare earth concentration.