PREPARATION OF DENSE BATIO3 CERAMICS FROM SOL-GEL-DERIVED MONOLITHIC GELS

Dense, small-grained BaTiO3 ceramics, with a grain size around 1 mu m and a relative sintered density >98%, were obtained at 1100 degrees C from sol-gel-derived gel monoliths without using any sintering additives. The monolithic gels as-prepared had a relative density of about 50% and consisted of ultrafine pseudo-cubic BaTiO3 particles (<50 nm), These gels, with a significantly high density compared with that of previous ones (approximate to 30%), have been synthesized at room temperature from a sol solution with a concentration of equimolar mixture of titanium isopropoxide and barium ethoxide (0.8 mol/L), using the methanol/2-methoxyethanol mixed-solvent system, Microstructural development of the gel monoliths with increasing sintering temperature and the dielectric properties of the obtained dense BaTiO3 ceramic have been in investigated.