Faraday and magnetic Kerr rotation measurements on Co and Ni films around M_2,3 edges

Faraday and longitudinal magnetic Kerr rotation measurements were performed on Co and Ni single layer films around their M_2,3 edges, at room temperature under an applied magnetic field of 0.82 T generated by a magnetic circuit composed of permanent magnets. The longitudinal Kerr rotation angle spectra are in good agreement with those calculated from the Faraday rotation spectra in Ni but different in Co. The main reason for the difference in Co was explained with the difference of the magnetization between a longitudinal Kerr (saturated) and a Faraday (unsaturated) configuration under the magnetic field of 0.82 T. This was supported by the calculated result from magnetic circular dichroism (1.2 T, 140 K) measurement on Co.