Process of Formation of the Aurivillius Phase Bi3NbTiO9 and Its Substitutes

Two series of the magnetically substituted Aurivillius phases, Bi3NbTi1–xMnxO9 and Bi2LnNbTiO9 (Ln = Nd–Ho), were synthesized. The substitution was found to be limited in both cases. The formation mechanism of the unsubstituted compound Bi3NbTiO9 was proposed on the basis of both isothermal and constant rate heating data. The stability of the derivatives of the intermediate compound Bi4Ti3O12 appears to be responsible for the observed substitution limits. The kinetics of formation of Bi3NbTiO9 from the binary oxides and the intermediate compounds were studied.