Laser Beam Assisted Kerr Microscopy for Investigations of New Magneto-optical Recording Layers

摘要

A promising method to increase the storage density in magneto-optical recording is the "center aperture detection for magnetically induced superresolution" (CAD-MSR). For this technique at least two layers are required. A layer system consisting of GdFeCo and TbFeCo was investigated by magneto-optical Kerr measurements at different temperatures. Above 300 K the magnetization of the GdFeCo layer switches from nearly in-plane to perpendicular. A domain structure was created in the TbFeCo layer and observed in a Kerr microscope which has been designed for this special purpose. Then, viewing from the GdFeCo side, a laser beam was focussed onto the sample. When the temperature in the laser spot was enhanced above 300 K the magneto-optical contrast increased corresponding to the increase of the remanent magnetization of the GdFeCo layer. In conclusion, the read-out process of the CAD-MSR can be demonstrated by direct observation.