The influence of foreign ions on the crystal lattice of barium titanate

From investigations of phase diagrams of ternary oxides the lattice sites of foreign ions and compensating vacancies are established. Large trivalent ions occupy barium sites and are completely compensated by titanium vacancies. Small pentavalent ions occupy titanium sites and are mainly compensated by titanium vacancies. During these investigations a new compound was found, Ba La4 Ti4 O15 isomorphous with Ba5 Nb4 O15.