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 the microstructure of the fired fibres obtained from sols containing different water and acid ratios, the merits of incorporating excess lead and/or adding manganese or calcium salts to the sols were also considered. 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 achieved from gels containing 2 mol % of added calcium nitrate. These fibres had a density ca. 7.4 g CM-3 and a grain size of ca. 0.3 mum.