SYNTHESIS AND CHARACTERIZATION OF PBTIO3 AND CA AND MN MODIFIED PBTIO3 FIBERS PRODUCED BY EXTRUSION OF DIOL BASED GELS

Lead titanate precursor gels were prepared using a diol sol-gel system . Water and nitric acid were added to the sols and their effect on the extrusion characteristics of the gels established. After examining th e microstructure of the fired fibres obtained from sols containing dif ferent water and acid ratios, the merits of incorporating excess lead and/or adding manganese or calcium salts to the sols were also conside red. It proved possible to produce unmodified PbTiO3 fibres that were crack-free having a diameter of ca. 250 mum and grain size of ca. 0.3 mum with a density of ca. 7.1 g cm-3. However, the best fibres were ac hieved from gels containing 2 mol % of added calcium nitrate. These fi bres had a density ca. 7.4 g CM-3 and a grain size of ca. 0.3 mum.