Magnetic interaction in Co/Ru/Co/Fe-SiO2 multilayers

J. GÓMEZ; A. BUTERA

San Carlos de Bariloche

Conferencia; 13th International Conference on Solid Films and Surfaces; 2006

We have studied the effect that a continuous ferromagnetic film produces on the superparamagnetism of  Fe nanoparticles  embedded in a SiO2 matrix. As the magnetic signal coming from the continuous film is usually much larger than the magnetization of the granular layer, we have grown (by sputtering techniques) the Fe-SiO2 film on top of a synthetic antiferromagnet (Co/Ru/Co). In this system the Co layers are coupled aniferromagnetically throughout a Ru spacer. Consequently the net magnetization signal is close to zero for small external applied fields. This multilayer enable us to obtain a relatively clean magnetization measurement coming mainly from the Fe nanoparticles.    Temperature dependent magnetization measurements indicate that the blocking temperature of the nanoparticles increases when compared to the values obtained in a granular layer which is not in contact with a continuous Co layer.