Understanding the structural and magnetic evolution of superparamagnetic Zn ferrites nanoparticles synthesized by an easy electrochemical process

•Synthesizing nanoparticles electrochemically with control of particle size and Zn content in the structure.•From maghemite nanoparticles to stoichiometric Zinc ferrite nanoparticles with the same size.•The inversion degree is always zero, regardless of the zinc content.•Zinc atoms located in tetrahedral sites break the super-exchange magnetic interaction.