46. Magnetic coupling in Fe/Fe-SiO2/Ni80Fe20 thin films

J. GÓMEZ; A. BUTERA; J. L. WESTON

Reñaca, Chile

Workshop; VII Latin American Workshop on Magnetism and Magnetic Materials; 2005

We have analyzed the magnetic behavior of a trilayer formed by two continuous ferromagnetic (FM) layers (Fe and Ni80Fe20) separated by a granular film of Fe-SiO2. The study was made as a function of the Fe volume concentration, x, and the spacer thickness, t, of the granular layer with x in the range 0.45 to 0.85 and t taking the values 1, 2, 4, 9 and 18 nm.The magnetic response of the films was characterized using ferromagnetic resonance and dc magnetization measurements.In the whole studied ranges of x and t, we have observed two absorption signals. The separation between the resonance fields and the intensity ratio depend on x and t evidencing the presence of an interlayer exchange between the Fe and the Ni80Fe20.Magnetization measurements also indicate that the continuous films are coupled through the granular layer. We have observed a simple or two step magnetization reversal process depending of the value of the interlayer exchange.