Effect of the dry nanodispersion procedure in the magnetic order of the Co3O4 surface

The ferrimagnetism at the interface of the Co3O4 nanoparticles and microparticles used as substrate depends on different parameters of nanoparticles dry dispersion methodology. The quantity of nanoparticles, the energy and the time employed in the process play a key role in the dispersion efficiency. A better dispersion of the nanoparticles produces a larger covering of the Al2O3 microparticles substrate and larger UV–vis absorbance and Ms. The magnetic order strongly depends on the number of interaction nanoparticle substrate related to dispersion degree. UV–vis absorbance is a good parameter to measure the dispersion and, therefore, a fingerprint of the magnetic order. Due to the relation between UV–vis absorbance and Ms, it was possible to optimize the dry dispersion parameter to obtain the maximum Ms.