Vectorial magnetometry using magnetooptic Kerr effect including first- and second-order contributions for thin ferromagnetic films

A new combination of different vectorial magnetometry techniques using magnetooptic Kerr effect is described. The processing of the experimental data contains the separation of linear and quadratic parts of the magnetization curves and determination of all three components of the magnetization vector in units of Kerr rotation without any normalization to the saturation values. The experimental procedure includes measurements with parallel and perpendicular polarized incident light and an external magnetic field parallel and perpendicular to the plane of incidence of light. The determination of the complex Kerr amplitude and the theoretic description of the data processing in assumption of small angles of incidence and also for larger angles of incidence using adequate scaling to the mean saturation value validate this vectorial magnetometry method. In the case of an absent out-of-plane component of the magnetization vector, the complete reversal process can easily be reconstructed and interpreted by monodomain states and domain splitting. The measurement procedure and the processing of the data are demonstrated for an ultra-thin epitaxial Fe film on MgO(0 0 1).