Impact of Silica-Modification and Oxidation on the Crystal Structure of Magnetite Nanoparticles

At present, the widespread use of iron oxide nanoparticles, including for commercial purposes, requires strict preservation their phase composition during application. The choice nanoparticle modifier and modification conditions is decisive due to high sensitivity oxygen in case using real (O2, pH change, etc.). In this work, we studied change magnetite nanoparticles after with 3-aminopropyltriethoxysilane (APTES) oxidation nitric acid order estimate protective potential silica shell. After by APTES acid, nonstoichiometric nature according XRD data increased, which indicates an increase transition forms compared initial sample (magnetite content decreased 27% 24%, respectively). contrast, Mössbauer spectroscopy detected a decrease index conditions, but strong exposure acid. It also showed that analyzing diffraction analysis same sample, one can obtain information not only about ionic “magnetite”, distribution ions different charges over crystalline amorphous parts preparation.