MAGNETIZATION REORIENTATION IN FERRIMAGNETIC GD27.5FE59CO13.5 DY28FE60CO12 DOUBLE-LAYERS/

We present experimental results on magnetization reversal for double-l ayer (GdFeCo/DyFeCo) magnetooptical alms. The structure of interest co nsists of a 40 nm DyFeCo layer with perpendicular magnetization and a 50 nm layer of GdFeCo with in-plane magnetization. A transition from i n-plane to perpendicular orientation of the magnetization in GdFeCo fi lm caused by the effect of exchange interaction with DyFeCo has been o bserved in just a small temperature range. For higher temperatures, th e exchange effect becomes smaller and GdFeCo magnetization returns bac k to in-plane orientation. On the basis of a micromagnetic model, we p redict a change in orientation of GdFeCo magnetization from in-plane t o perpendicular when it is coupled to DyFeCo film in a certain tempera ture range. This transition is sensitive to the magnetic properties of each layer that are dependent on temperature and on the values of com pensation and Curie temperatures of both GdFeCo and DyFeCo films.