Kinetics controlled aging effect of ferroelectricity in Al-doped and Ga-doped BaTiO3

Abstract

Our experiments on ferroelectric aging of Al3+- and Ga3+-doped BaTiO3 ceramics reveal the crucial role of migration kinetics of point defects (oxygen vacancies) besides the thermodynamic driving force based on the symmetry conforming short-range ordering scenario. The doping with Ga3+ or tiny Al3+ ions shows the clear aging effect, while the high-level Al3+-doping suppresses the aging effect. The suppression is mainly attributed to the kinetically limited migration of oxygen vacancies due to the lattice shrinkage, while the other mechanisms may also make sense.

Ferroelectric aging behaviors of BaTi0.995Mn0.005O3 ceramics: grain size effects

“…Earlier works on Mn-doped BaTiO 3 single crystal and other FE materials have established the volume effect as one of the governing mechanisms, while other mechanisms associated with grain boundary effect or domain wall pinning may be also plausible [1,[3][4][5][6][7][8][9]. Generally, all these mechanisms are based on the stabilization of domain wall pattern by defects [1,[3][4][5].…”

Antiferroelectric-like properties and enhanced polarization of Cu-doped K0.5Na0.5NbO3 piezoelectric ceramics

“…8,9 Since the volume effect is related to the migration of charged carriers, both the thermodynamic and kinetic behaviors of these carriers should be considered. The crucial role played by the migration kinetics of point defects has been demonstrated in Al 3þ -doped BaTiO 3 ceramics, 10 where the Al 3þ -doping leads to lattice shrinkage and suppresses the FE aging effect at high level doping. Moreover, double P-E loops have also been reported in some acceptor-doped ferroelectrics without aging, such as in K þ -doped PbZr x Ti 1Àx O 3 (PZT) 11,12 and Cu 2þ -doped K 0.5 Na 0.5 NbO 3 (KNN) ceramics.…”

External field effects on aging phenomenon of acceptor-doped BaTiO3 ceramics

“…(The effects of ionic radius and ionic valence on aging phenomena have been reported in our previous article. 21 ) Fig.2 displays that after an appropriate time of aging, all samples show a similar double hysteresis loop under smaller applied electric field, regardless of ionic radius or ionic valence of the acceptor. However, with increasing the applied field, the completely constricted loops developed under smaller electric field little by little start to open.…”

“…The underlying mechanism is that the Al-doping induced lattice shrinkage would kinetically hinder the OVs migration, which has been demonstrated in our previous article. 21 The P-E loops of all samples at room temperature were measured using the RT6000HVS standard ferroelectric testing unit.…”