Magnetic nanoparticles (NPs) are especially interesting for several biomedical applications due to their chemical surface, especially for targeted cancer imaging and therapeutics. In order to realize these applications, it is important to know their magnetic properties among other complementary properties that help to improve the understanding of the synthesis process. In this work, we report the magnetic properties of polyethyleneimine-coated magnetite (PEI-Fe3O4) NPs synthesized by a one-step method via the co-precipitation method and using PEI as a stabilizer. Transmission electron microscopy (TEM) images revealed agglomerated magnetic nanoparticles with an average size of similar to 10 nm; meanwhile, the X-ray diffraction (DRX) analysis confirmed a pure magnetite phase. The study of magnetic properties shows a superparamagnetic system with coexistence of non-interacting single NPs wi...

In this work, we study the crystallization and surface morphology of Cu thin films (exposed to environment) growth on SiO2/Si subsstrates. The samples thermally treated using a tubular furnace bet ween temperature range 250-1000ºC during an elapsed time of 3 hours, after was cooling to a rate of 1.4ºC/min. The crystalization process was measured by X-ray difraction (XRD), meanwhile the surface morphology was observed with scanning electron microscopy (SEM). The results was analyzed and permit us to know the temperature dependecy of the dynamics of surface atoms on the Cu/SiO2 system, are the range between 400-500ºC. During the annealing an oxidation process on sample surfaces occur and the presence of Cu silicides are detected.