Magnetic properties of Co-Ni alloy nanoparticles prepared by the sol gel technique

The magnetic properties of Co, Ni and CoxNi(1-x) alloy nanoparticles with different composition (0 < x < 1), prepared by the sol-gel route, were investigated. ZFC and FC magnetization measurements show that the blocking temperature increases with the Co content, while a maximum in the anisotropy constant was found for x = 0.7. Room temperature FMR measurements, suggest that in samples with larger Co content (x >= 0.66) interparticle interactions play a relevant role in determining their magnetic properties.