Preparation of Dense BaTiO ₃ Ceramics from Sol‐Gel‐Derived Monolithic Gels

Dense, small‐grained BaTiO 3 ceramics, with a grain size around 1 μm and a relative sintered density >98%, were obtained at 1100°C from sol‐gel‐derived gel monoliths without using any sintering additives. The monolithic gels asprepared had a relative density of about 50% and consisted of ultrafine pseudo‐cubic BaTiO 3 particles (<50 nm). These gels, with a significantly high density compared with that of previous ones (∼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 BaTiO 3 ceramic have been investigated.