Magnetic Granulometry and Mössbauer Spectroscopy of Synthetic FemOn–TiO2 Composites

FemOn–TiO2 particle aggregates have been obtained using the sol–gel method and hydrothermal treatment. It is shown that the synthesis conditions favor forming composites that contain titanomagnetite in very low concentrations. Hysteresis loops and demagnetization curves of anhysteretic remanent magnetization were measured with a vibration sample and a SQUID magnetometer, respectively. Mossbauer spectroscopy, bulk magnetic properties, scanning electron microscopy (SEM) observations, coupled with the theoretical analysis of magnetostatic interaction between finely dispersed particles lead to a conclusion that the studied composites can be viewed as groups of interacting clusters 2– $20~\mu \text{m}$ in size, consisting of chemically heterogeneous, mostly single-domain or close to single-domain particles with an average size of about 100 nm.