Published online by Cambridge University Press: 10 February 2011
Surface properties of BaTiO3 which contain different Ba/Ti ratios were examined by FTIR spectroscopy. Most of the carbonates on the surfaces of these powders were removed by heat treatment at 1200°C. However, it was more difficult to remove the carbonates from the powder with a higher ratio of Ba/Ti. Analysis of the heat treated, aged powders in humid air showed that the barium-excess powder recovered carbonates within several hours. In contrast, titanium-excess powders took a longer time, indicating that barium ion concentration is a reaction-control parameter. It was found that oleic and stearic acids were effective in retarding the degradation of the BaTiO3 powders. They also made the dissolution rate of the powders in water considerably slower.