PbTiO3 film and powder materials have been obtained from a sol prepare
d at room temperature by mixing lead(II) acetate trihydrate (LAT) and
tetraisopropylorthotitanate (TPOT) in methoxyethanol. The sol-gel proc
ess was studied by means of Pb-207 nuclear magnetic resonance and infr
ared spectroscopy, differential thermal analysis and X-ray diffraction
measurements. This investigation shows that an interaction between LA
T and TPOT occurs immediately on mixing in solution and, as a result o
f the interaction, the lead and titanium compounds are indistinctly li
nked together through bidentate acetate bridging. This linkage remains
unchanged during solution reactions and gelation, Pb-O-Ti bonding bei
ng absent at this stage. Pb-O-Ti bonding in the sol-gel materials is b
elieved to be first formed between 200 and 350 degrees C during the de
composition of the OAc group of LAT and its removal from the gel. The
gel retains its amorphous state on heating at 370 degrees C for 1 h. A
n unidentified primary crystal phase appears after heating the gel at
400 degrees C for 1 h, and it is transformed into perovskite PbTiO3 cr
ystals at 500 degrees C and higher temperatures.