A dielectric peak at about 517C in Bi4Ti3O12 was related to a domain transformation at 445C in Bi2Ti2O7 and at 468C in Bi2Ti4O11, and moved to a higher temperature with increasing Bi2Ti4O11 concentration in the solid solution. A marked fall in the dielectric value of the solid solution was then observed under direct-current bias. This was due to the loss of relaxation mechanisms which originated from the defect-dipole orientation as well as from the O-vacancy configuration. The E-field dependent resistivity in Bi2Ti4O11 at various temperatures also indicated the occurrence of defect-dipole rotation and O-vacancy migration, together with macro-domain alignment within grains.

Investigations of Morphotropic Phase Transformations in the Solid Solution of Bi4Ti3O12 and Bi2Ti4O11 Accompanied by Defect Dipole Orientation and Oxygen Vacancy Migration. A.Q.Jiang, Z.X.Hu, L.D.Zhang: Journal of Applied Physics, 1999, 85[3], 1739-45