Longitude magneto optical Kerr effect of Fe/GaAs (0 0 1) with Al overlayers

The longitude magneto optical Kerr effect (LMOKE) is investigated on ultrathin Fe film grown on GaAs (0 0 1) substrate with Al overlayer. The formula of the longitude magneto optical Kerr effect is derived to find out the influence of the Al overlayer on the magneto optical properties of Fe/GaAs (0 0 1) sample. Results obtained from this formula fit very well with the experimental data. The change of the Kerr rotation as a function of the incident angle is also given, which can be used to find a proper angle in sample measurement. A numerical simulation was carried out to find out the relation between Kerr rotation and optical properties of the overlayer. Results from this simulation can be used to select the best overlayer material to protect the Fe/GaAs (0 0 1) sample.

► LMOKE is investigated on Al/Fe/GaAs for the first time.
► Influence of the overlayer on the properties of the sample is investigated.
► Method is given to select the best overlayer material to protect the sample.
► Method is given to find a proper incident angle in sample measurement.