Asymmetric polarization of defect dipoles in Bi4Ti3O12 and Bi2Ti4O11 ceramics with Na+ and La3+ modifications

Asymmetric polarization of defect dipoles around phase transitions develops the resistivity hysteretic behavior and imprint failure of Bi4Ti3O12 and B i2Ti4O11 ceramics under various electric fields. The polarization was deter mined qualitatively by P-E hysteresis loop measurements along with the dete ction of current transient with time. A reduction in defect-dipole polariza tion occurs at high-field strength due to the defect-dipole decomposition a nd/or oxygen vacancy migration. [S0163-1829(99)11437-1].