Investigation of the pyrolysis of lead zirconate titanate gels with coupled differential thermal analysis, thermogravimetry and infrared spectroscopy

The pyrolysis of organic components in the sol-gel preparation of lead zirconate titanate (PZT) from lead acetate and zirconium and titanium propanolate in methoxyethanol is studied with simultaneous differential thermal analysis, thermogravimetry and infrared spectroscopy. The first pyrolysis step of the dried PPT gel, yielding acetone and CO2 similar to the pyrolysis of lead acetate, indicates that most of the acetate groups are bonded to Pb2+ In the second step, the remaining organic components are oxidized to CO2 and H2O. The formation of undesired carbon residues during pyrolysis from unhydrolysed alkoxide groups and acetate groups bonded to Zr4+ and Ti4+ can be prevented by steam treatment of the dried gels. Activation energies for the different pyrolysis steps of lead, zirconium and titanyl acetate, lead decanoate and PZT gels are given. (C) 1998 Kluwer Academic Publishers.