A THEORETICAL-STUDY OF THE MAGNETOOPTICAL KERR-EFFECT IN FECO, FENI, FEPD, FEPT

The magneto-optical (MO) Kerr effect of FeX compounds with X--Co, Ni, Pd, Pt is studied theoretically using self-consistent band structure c alculations. The mo spectra so determined agree with experimental Kerr spectra in overall shape but not in magnitude, the latter being sligh tly underestimated for FeCo and overestimated for FePd and FePt. The t rend in the spectra for FeNi, FePd and FePt is explored and by investi gating the effect of different crystal structures for FeCo and FePd we demonstrate that the Kerr spectrum depends sensitively on the local a tomic environment of the Fe and Pd or Co atoms. Our calculations sugge st that the computed spectra are those of highly ideal samples, which only approximately possess the atomic characteristics of the surfaces and bulk of real polycrystalline samples.