LARGE ELECTROMECHANICAL ANISOTROPIC MODIFIED LEAD TITANATE CERAMICS .1. PROCESSING

Modified lead titanate (PT) oxalates were prepared by mixing an ethanol solution with (calcium, lanthanum, neodymium, samarium or gadolinium) and titanium with an ethanol solution of oxalic acid containing lead, and (cobalt and tungsten) or manganese by blending. The resulting complex oxalate, after washing with ethanol for several times, was an amorphous powder with a very fine particle size. The amorphous coprecipitate gave, on calcining, a high sinterable modified lead titanate powder of compositions (Pb0.76Ca0.24) ((Co0.5W0.5)0.04Ti0.96)O3 or (Pb0.88La0.08) (Ti0.98Mn0.02)O3 which, on sintering, produced highly densified bodies (≥98% theoretically density) at relatively low te7peratures 009Mouand C. RC for Ca-PT and Ln-PT, respectively). Linear thermal expansion measurements, microstructural development of the modified lead titanates, and the influence of grain size on c/a ratio have also been studied.