Nanostructured Ferrite Formation in Borosilicate Glass

We present the preparation, structural, and magnetic properties of a series of Fe-containing borosilicate glasses as a function of the ratio SiO2/Fe2O3 which is ranging from 1.49 to 2.68. The role of nucleators (Cr2O3 and P2O5) was also investigated. X-Ray diffraction has revealed the formation of magnetite as the major or unique crystalline phase. As SEM micrographs have revealed, the addition of P2O5 give rise to a finer structure as compared with Cr2O3. In addition, the same oxide decreases the temperature of structural transition with almost 100 °C. The magnetization data reveal a two step transition at low temperatures: a high temperature transition at Tv = 128 K, which we attribute to the Verwey transition, and a low temperature transition at Ts = 48 K which, most likely, is the result of change in the dynamic of the domain motion.