Mössbauer studies of magnetic Fe2O3/SiO2 nanocomposites

Suppl. E (2006): Proceedings of the International Colloquium "Mössbauer Spectroscopy in Materials Science" (June 11–15, 2006, Kočovce, Slovak Republic)A large variety of glass and glass ceramics may be obtained by sol-gel process from hydrolysis of tetraethoxysilane. The transformation involves hydrolysis and polycondensation reactions leading to the growth of clusters that eventually collide together to form a gel. The structure and properties of the final product have been found to be strongly dependent on the initial conditions of preparation. Silica nanocomposites based on Fe2O3/SiO2 were prepared with the help of ultrasonic activation and subsequent annealing in nitrogen atmosphere or air with concentrations of iron oxide of about 20 to 30wt.%