Preparation of undoped lead titanate ceramics via sol-gel processing

Crack-free, undoped PbTiO3 ceramics were fabricated successfully using sol-gel-synthesized powder prepared from chelated titanium alkoxide and lead acetate, The sintered ceramics, 8.3 mm in diameter and 6-8 mm thick, were 96% dense. In the present study, PbTiO3 ceramics with excess lead (Pb:Ti = 1.1:1.0) had large grains, averaging 14.3 mu m Lower-lead ceramics (Pb:Ti = 1.0:1.0 and 0.9:1.0) had smaller grains, averaging 1.8 mu m, The PbTiO3 ceramics with a high lead content cracked during sintering at 1150 degrees C, whereas the other ceramics did not crack. Excess lead, in a more-than-stoichiometric ratio, promoted grain growth and caused disintegration of the ceramics. Therefore, uncracked PbTiO3 ceramics apparently can be fabricated by avoiding excess lead, possibly because restricted grain growth in low-lead ceramics causes low residual stress over many small grains during transition, The electrical properties measured in the present study for PbTiO3 ceramics,vith a Pb:Ti ratio of 1:1 are d(33) = 35 pC/N, K-3 = 64, k(p) = 0.59, and k(t) approximate to 0.