The Magneto-Optical Spectra and Behaviour of the Joint Density of States of the Intermetallic Compounds RFe sub 2 (R = Gd, Tb, Dy, Ho, Er) and YFe sub 2

Room temp. measurements of the equitorial Kerr-effect spectra ( delta ) for the angle of incidence phi = 70 deg show that the structure for the RM sub 2 compounds depends on the atomic number of the rare earth. The delta spectra of ErFe sub 2 and HoFe sub 2 exhibit a similarity to the YFe sub 2 spectrum. The epsilon exp ' sub xy spectra calculated using optical constants determined from reflectivity measurements show that the differences in the delta spectra mentioned above are present in the epsilon exp ' sub xy spectra, and hence in the joint density of states. Theoretical calculations of the band structure of the RFe sub 2 compounds in which the s--d hybridization and the influence of the 4f states on the conduction electron states are taken into account should aid in understanding these differences. 4 ref.--J.J.P.