Ferroelectric behaviours dominated by mobile and randomly quenched impurities in modified lead zirconatetitanate ceramics

Mechanism of aging effect in hybrid-doped BaTiO3 ceramics: electronegativity and ionic radius

In hybrid-doped BaTiO₃ ceramics, acceptor (A³⁺) with higher ER tends to form defect pairs with donors (D⁵⁺ or D³⁺).

Defect control for polarization switching in BiFeO₃ single crystals

BiFeO₃ (BFO) single crystals were grown and the effects of Zn and Mn co-doping on the polarization and leakage current properties were investigated at 25 °C for establishing materials design based on defect chemistry. Although Zn doping or Mn doping led to a deterioration in the properties, Zn-Mn co-doping led to a large remanent polarization (36 μC/ cm²), a low coercive field (19 kV/cm), and a relatively low leakage current density (~10⁻⁸ A/cm²). It is proposed that defect dipoles composed of Zn²+ and Mn⁴+ act as effective nucleation sites for ferroelectric domains during polarization switching in BFO crystals.

POINT DEFECT CHEMISTRY OF METAL OXIDE HETEROSTRUCTURES

▪ Abstract  This article reviews the defect chemistry of perovskite ferroelectric oxides such as barium titanate and lead zirconate titanate. Such metal oxides are being considered for a wide range of applications that include nonvolatile memories and dynamic random access memories. Time-dependent degradation of these devices is controlled at least in part by point defects, which are determined by the defect chemistry of the material. The role of point defects on Pb(Zr,Ti)O3 thin film device properties such as fatigue, switching, polarization relaxation and imprint is discussed.