As to indicate the effect of the le

As to indicate the effect of the leaching process we estimated the dissolved Ba2+ content in the liquid phase after separation from the solid. The results of the analysis of these, liquids for the various leaching conditions are summarized in Tables 1–3 (the amount of dissolved Ba was correlated to the Ba in the starting BaTiO3 powder). At first, the amount of dissolved Ba ions can directly be influenced by the variation of the leaching time. The results regarding the time dependence of the leaching of BaTiO3 seeds at 100 ◦C in 0.1 M acetic acid are shown in Table 1: the dissolved Ba amount doubles from 0.74 to 1.54 mol% by prolonging the leaching time from 1 to 4 h. With increasing Ba dissolution the Ba depleted layer acts as a buffer. Thus, after leaching for 24 h a dissolution of only 2.0 mol% Ba2+ was found. Assuming the leaching kinetics of the dissolution of the Ba ions from the BaTiO3 seeds follows Eq. (1), according to the solution of Fick’s diffusion laws: