Effect of milling on the surface functionality of BaTiO3–CaSnO3 ceramics

The effect of milling in the presence of a surfactant upon the surface functionality (content of various donor–acceptor centers and corresponding functional groups) of BaTiO3–CaSnO3 powdered ferroelectric ceramics was studied using the selective adsorption of acid–base indicators. Milling was found to cause similar changes in the content of certain surface centers with pKa ∼7.0+x and ∼7.0–x (shifted by almost the same values from the neutral point). The observed surface behavior is determined by the simultaneous formation of such centers upon bond disruption and their simultaneous shielding due to the surfactant adsorption. On the contrary, the contents of some pairs of surface centers were found to undergo opposite changes as a result of their mutual transformations. The obtained data are promising for the prediction and modification of surface functionality for various oxide based materials and other solids.