Microstructure and Dielectric Properties of Nanostructured TiO₂ Ceramics Processed by Tape Casting

Effects of different solvent systems and dispersant on tape casting slurries of TiO2 nanopowders (∼40nm) were studied by rheological measurements. It was found that Xylene/Ethanol with phosphate ester (PE) as dispersant gave the best dispersion quality which resulted in highly homogenous, dense, smooth and crack-free tapes. The presence of phosphate ester inhibited the sintering of TiO2 powders and refined the grain size. Sintered tapes with 200-300nm grain size and relative density over 90%, had dielectric constant ∼100, dielectric loss less than 1% and dielectric breakdown strength (BDS) over 1000KV/cm