Q. Tan et al., Role of lower valent substituent-oxygen vacancy complexes in polarization pinning in potassium-modified lead zirconate titanate, APPL PHYS L, 75(3), 1999, pp. 418-420
The dependence of polarization switching on thermal histories has been inve
stigated for K1+-modified lead zirconate titanate (PZT) ceramics by Sawyer-
Tower polarization methods. It was found that double-loop-like polarization
characteristics in the aged condition could be reversed to normal single l
oop polarization characteristics by quenching specimens from above the ferr
oelectric phase transition temperature. However, the P-E curves reversed ba
ck to double-loop-like characteristics after reaging specimens at elevated
temperatures. Excess oxygen vacancies in La3+-modified PZT were not found t
o result in double-loop-like polarization hysteresis, whereas excess oxygen
vacancies in K1+-modified PZT did. These results provide evidence for role
of K1+-oxygen vacancy complexes in polarization pinning. (C) 1999 American
Institute of Physics. [S0003-6951(99)00929].