Surface modification of BaTiO3 with yttrium, and dissolution and adsorption/precipitation behaviors of BaTiO3

An attempt was made to retard the dissolution of Ba ions from BaTiO3 by coating Y compounds on the BaTiO3 particle surface. A hysteresis in the electrokinetic behavior of as-received BaTiO3 occurred during sequential acid and base titrations, while there was no hysteresis in the Y-coated BaTiO3. In the bare BaTiO3, dissolved Ba ions are adsorbed and/or precipitated onto the surface during sequent base titration to yield a more positively charged Ba-rich phase on top of the Ba-depleted lattice. On the contrary, the dynamic mobility of Y-coated BaTiO3 during base titration closely followed the corresponding acid titration, providing that the starting surface of Y-coated BaTiO3 and the surface after acid-base treatment was the same. It is suggested that Y compounds on the BaTiO3 particles retard the dissolution of Ba ions from BaTiO3.