Nd-(Fe, Co) 膜の磁気光学力一効果

抄録

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 (θ_K), 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 θ_K 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 θ_K at 300 nm. In pseudobinary system Nd-(Fe, Co) films, θ_K is larger than any other binary system with the same Nd composition in the entire wavelength region, and Nd₂₂(Fe₆₅Co₃₅)₇₈ film shows θ_K of about 0.58° at 300 nm.