TGA-FFIR study of a lead zirconate titanate gel made from a triol-based sol-gel system

A Pb(Zr,Ti)O-3 precursor gel made from a sot prepared using 1,1,1,-tris(hydroxymethyl)ethane, lead acetate and zirconium and titanium propoxides, stabilised with acetylacetone, was analysed using TGA-FTIR analysis. Decomposition under nitrogen (N-2) gave rise to evolved gas absorbance peaks at 215 degrees C, 279 degrees C, 300 degrees C and 386 degrees C, but organic vapours continued to be evolved, along with CO2 and CO until similar to 950 degrees C. The final TGA step in N-2 is thought to relate to decomposition of an intermediate carbonate phase and the final elimination of residues of triol or acetylacetonate species which form part of the polymeric gel structure. By contrast, heating in air promoted oxidative pyrolysis of the final organic groups at <= 450 degrees C. In air, an intermediate carbonate phase was decomposed by heating at similar to 550 degrees C, allowing Pb(Zr,Ti)03 to be produced some 400 degrees C below the equivalent N-2 decomposition temperature. (C) 2008 Published by Elsevier B.V.