Abstract
Magneto-optical contribution of Nd in vacuum evaporated Nd-(Fe, Co) films has been investigated by measuring the wavelength dependence (λ=250∼800 nm) of Kerr rotation (θK), together with the spectra of photoelectrons emitted under X-ray (XPS). The Kerr rotation for Nd-Co films increases with decreasing λ when Nd concentration is over 14 at.% and shows a peak at 300 nm, while the Kerr spectra of Nd-Fe films become flat with increasing Nd content. The compositional dependence of Kerr spectra for Nd-Co and Nd-Fe films is characterized by the following two factors, 1) the contribution of Nd to θK at short wavelength, and 2) the differences of the Kerr spectra between crystalline and amorphous states of Co or Fe. The XPS intensity for Nd-Co and Nd-Fe shows a maximum at about 4.2 eV below the Fermi level, which corresponds to the peak of θK at 300 nm. In pseudobinary system Nd-(Fe, Co) films, θK is larger than any other binary system with the same Nd composition in the entire wavelength region, and Nd22(Fe65Co35)78 film shows θK of about 0.58° at 300 nm.
