Novel synthesis methods for new materials in solid state chemistry

The most common method used for synthesizing inorganic solids is the so-cal led 'ceramic method' which involves synthesizing at elevated temperatures a nd leads to thermodynamically stable phases. This method has a serious limi tation because many inorganic solids of current interest are rather metasta ble and consequently their preparation requires low temperature methods. In this article, we have reported some methods of synthesis which also includ e methods that belong to soft-chemistry routes. The selected examples prese nted in this paper are: (1) the intercalation and or deintercalation of oxy gen in oxides by electrochemical oxidation or reduction in aqueous or nonaq ueous solutions, (ii) the use of chemical agents such as NO2 or borohydride s for obtaining oxides with tunneled and lamellar structures, (iii) a multi stage synthesis processing for intercalating, in layered oxygenated materia ls, anionic species and acrylic monomers and polymers, (iv) the supercritic al fluid processing for preparing nitrides, carbon-nitrides, lamellar oxide s and oxy-(hydroxy-) fluorides, and (v) the mechanical alloying for synthes izing new Mg-based binary intermetallics.