Materials with nanometer size particles exhibit unique and physical properties. In particular, nanocomposite materials, composed of nanometric metal and metal oxide particles embedded in vitreous matrices, present a variety of interesting magnetic, electric and catalytic properties, that are strongly size-dependent. Among the different preparation methods which can be used to obtain this kind of materials, the sol-gel process is particularly interesting because it is affected by several parameters which allow a versatile control of the structural, textural and chemical properties of the final products.
