Effect of different additions on the crystallization behavior and magnetic properties of magnetic glass–ceramic in the system Fe2O3–ZnO–CaO–SiO2

This work pointed out the preparation of a magnetic glass–ceramic in the system Fe2O3·ZnO·CaO·SiO2. The base composition was designed to crystallize about 60% magnetite. The influence of adding TiO2, Na2O and P2O5 separately or as mixtures was studied. The DTA of the glasses revealed a decrease in the thermal effects by adding P2O5, TiO2 and Na2O in an increasing order. The X-ray diffraction patterns showed the presence of nanometric magnetite crystals in a glassy matrix after cooling from the melting temperature. The crystallization of magnetite increased by adding TiO2, and P2O5, respectively, and decreased by adding Na2O. Heat treatment was carried out for the glasses in the temperature range of 1000–1050 °C, for different time periods, and led to the appearance of hematite and β-wollastonite, which was slightly increased by adding P2O5 or TiO2 and greatly enhanced by adding Na2O. Samples containing mixtures of TiO2, Na2O, and P2O5 showed a summation of the effects of those oxides. The microstructure of the samples was examined by using TEM, which revealed a crystallite size of magnetite to be in the range of 52–90 nm. Magnetic hysteresis cycles were analyzed using a vibrating sample magnetometer with a maximum applied field of 10 kOe at room temperature in quasi-static conditions. From the obtained hysteresis loops, the saturation magnetization (Ms), remanence magnetization (Mr) and coercivity (Hc) were determined. The results showed that the prepared magnetic glass–ceramics are expected to be useful for a localized treatment of cancer.