ASYMMETRY OF HYSTERESIS PROPERTIES OF THE LAYERS IN DOUBLE-LAYERED EXCHANGE-COUPLED MAGNETIC-FILMS

Switching of amorphous double layered binary and ternary rare-earth (RE) cobalt alloys films with perpendicular anisotropy in the layeres have been studied. Specimens were prepared by ion-plasma sputtering in Ar atmosphere on glass or silicon substrates. Before the upper layer was sputtered, the down one had being exposing for some time out of active zone of sputtering chamber. Hysteresis loops were measured from both sides of film by polar Kerr effect method. X-ray difractometer and AES spectrometer has been used for structure investigation and composition analysis. Microdispersed polycristalline RE oxide region with the thickness about 10 nm were detected both on free surface of the film and on the interlayer boundary. It is found that neither oxidized interlayer nor surface influences the switching of upper layer, but hysteresis loops from down one strongly distort when exposition time exceeded 5 minutes. For explanation of peculiarities of switching mechanism of oxidation of film's surface is proposed.