Influence of Sr/Ti Stoichiometry on the Densification Behavior of Strontium Titanate

In order to control the preparation of strontium titanate with a well-defined Sr/Ti stoichiometry produced by the mixed oxide route, dilatometric experiments have been conducted for compositions with Sr/Ti ratios ranging from 0.996 to 1.005. A significant change in sintering behavior has been detected going from a titania rich to a strontia rich composition. Combining observations of the microstructural evolution during different stages of sintering with results on defect chemistry from the literature makes an assessment of the basic mechanisms of sintering possible. The influence of zirconia abrasion from milling balls has been identified to be equal to a titania excess of the same amount. By means of dilatometric measurements it is possible to evaluate the A/B ratio with accuracy higher than 0.2 mol% from the shrinkage curves, providing a highly sensitive tool for the analysis of the stoichiometry in SrTiO(3).