A STUDY OF AMORPHOUS PRECURSORS FOR PBZRO3-PBTIO3 BASED CERAMIC MATERIALS

Amorphous precursors for PbZrO3 and PbTiO3 ceramics were prepared from lead acetate and the transition metal n-propoxide in n-propanol or n- butoxide in n-butanol and hydrolysed with an excess of water. Accordin g to GLC and TGA/EGA analyses, the type of alkoxide group influences d istinctly the structure of heterometallic precursors, i.e., oxo or ace tate bridging, and the amounts of hydroxyl and organic groups bound to the metal network. The local environments of metal atoms in the amorp hous precursors were also studied by EXAFS. The analysis reveals that in Pb-Zr precursors alkoxide groups modify the coordination spheres of the zirconium atoms. Conversely, local environments of both lead and titanium atoms within the analysed range of 3.4 A depend weakly on the type of alkoxide used.