Superparamagnetic Behavior at Room Temperature through Crystal Chemistry Modification and Particle Assembly Formation: Zinc and Nickel Ferrite Systems

Zinc and nickel ferrites were prepared through a solvothermal method with different microstructures: as assemblies of particles and not forming assemblies. By means of Raman spectroscopy, the cation distribution in the spinel structure has been evaluated for all the samples to understand the magnetic behavior characterization. The influence of the assembly microstructure type into the superparamagnetic behavior has been fully studied, and it seems to drastically increase the magnetic response of the samples through a mechanism of favored dipolar interactions.