Enhanced magneto-optical Kerr effect in spontaneously ordered FePt alloys: Quantitative agreement between theory and experiment

Abstract

A chemical-ordering-induced peak in the polar magneto-optical Kerr effect spectra of FePt compounds is found to be in quantitative agreement with predictions based on ab initio magneto-optical calculations. Experimental spectra of epitaxial molecular-beam-epitaxy grown FePt(001) films reveal a more than twofold enhancement of the Kerr rotation if full chemical ordering is present. A spectral feature at 2-eV photon energy shows a peak Kerr rotation of up to \ensuremath{\sim}0.8\ifmmode^\circ\else\textdegree\fi{}, which is strongly correlated with the presence of perpendicular magnetic anisotropy in ordered compound films.