Chemical synthesis of nanosized oxides

Abstract

Fine powder of single and binary mixed oxides can be produced by decomposition of the respective metal nitrates and polyvinyl alcohol (PVA) or, a mixture of PVA and polyacrylic acids. These mixtures, after spray drying, yield a brown fluffy mass, which is spontaneously combustible and the heat liberated is sufficient for the crystallization of the desired oxide phase. The rate of combustion controls the growth of the particles. This can be manifested by combustion of the mixture in controlled atmosphere. The nanoparticles of the oxide system studied are: spinels [MFe2O4 where M = Ni(II), Co(II), Zn(II), Mg(II)]; orthoferrites [MFeO3 where M = Gd(III), Sm(III)]; LaAlO3, NdGaO3, CaO/MgO/Y2O3 stabilized zirconia (ZrO2); lead zirconate titanate (PZT), lanthanum modified lead zirconate titanate (PLZT) and BaTiO3.