Function of glycine during solid-state reaction toward well-crystallized fine particulate barium titanate

摘要

Effects of glycine added to BaCO_3 and TiO_2 mixtures were examined during a solid-state reaction toward phase pure BaTiO_3 for MLCC with the average particle size below 180 nm and the tetragonality, c/a, above 1.009. Changes in the states of glycine during heating were monitored by differential thermogravimetry and high-temperature X-ray photoelectron spectroscopy. Glycine residue persists up to around 350 ℃ and destabilizes Ti-O bonds in TiO_2 prior to the initiation of reaction toward BaTiO_3. This, in turn, leads to a decrease in the reaction termination temperature due to higher mobility of Ba~(2+) ions through the reaction zone.