Ferroelectric aging effect in hybrid-doped BaTiO3 ceramics and the associated large recoverable electrostrain

Abstract

Acceptor doping and donor doping have been known to result in opposite ferroelectric aging effects, but the aging effect of hybrid-doped (acceptor+donor) ferroelectrics has remained unclear. In this letter the authors report the aging effect in Mn3++Nb5+ hybrid-doped BaTiO3 ceramics with acceptor fixed at 1mol% but with donor varied from 0.5to2mol%. The authors found surprisingly that ferroelectric aging existed in all the samples, no matter which of the two, acceptor or donor, was dominant: all the samples showed a double hysteresis loop after aging, but with increasing donor (Nb5+) concentration the coercive field and hysteresis decrease. Meanwhile, a large nonlinear recoverable electrostrain up to 0.17% (due to reversible domain switching) was observed at 3kV∕mm, which exceeded that of acceptor-monodoped ceramics and was about twice the piezoelectric strain of hard lead zirconate titanate. These results demonstrate that hybrid doping is an effective way to enhance the domain-switching-related electrostrain properties. Finally, the aging effect of hybrid-doped ferroelectrics was explained.

Evolution of dielectric and ferroelectric relaxor states in Al3+-doped BaTiO3

“…Large dispersion in the dielectric curves during orthorhombic -tetragonal phase transition is therefore attributed to the differences in the rates of migration of oxygen vacancies to the O(1) site as required by the symmetry confirming principle of defects. [15][16][17][18][19][20][21] The volume effect in this case is also confirmed from the reduction of dielectric permittivity ( Fig. 1(c)).…”

Double Hysteresis Loop in BaTiO3-Based Ferroelectric Ceramics

“…This kinds of antiferroelectric behavior is also observed in Pb(Zr, Sn, Ti)O 3 and Pb(La, Zr, Sn, Ti)O 3 ceramics (Berlincourt, 1963(Berlincourt, , 1964Biggers & Schulze, 1974;Gttrttritja et al, 1980;Shebanov et al, 1994). Interestingly, the double hysteresis loops have been observed in BaTiO 3 (Merz, 1953), BaTiO 3 -based (Ren, 2004;Zhang & Ren, 2005Liu et al, 2006), (Na 0.5 Bi 0.5 )TiO 3 -based (Takenaka, 1991;Sakata & Masuda, 1974;Tu et al, 1994;Sakata et al, 1992), (Ba, Sr)TiO 3 (Zhang et al, 2004), KNbO 3 (Feng & Ren, 2007, 2008, BiFeO 3 (Yuen et al, 2007) and other lead-based perovskite ceramics such as Pb(Yb 0.5 Ta 0.5 )O 3 (Yasuda & Konda, 1993) , Pb(Fe 2/3 W 1/3 )O 3 -Pb(Co 1/2 W 1/2 )O 3 (Uchino & Nomura, 1978), Pb(Sc 0.5 Ta 0.5 )O 3 (Chu et al, 1993) and Pb(Co 1/2 W 1/2 )O 3 (Hachiga et al, 1985) over the past decades. However, the observed double hysteresis loops have different physical origins.…”

“…Many mechanisms such as the grain boundary effect (Karl & Hardtl, 1978), the domain-wall pinning effect (Postnikov et al, 1970), the volume effect (Lambeck & Jonker, 1986) and symmetry-conforming short range ordering (SC-SRO) mechanism of point defects (Ren, 2004;Zhang & Ren, 2005Liu et al, 2006) have been proposed to explain this phenomenon. Although all these models seem to be able to provide a self-consistent explanation of the double hysteresis loop in aged ferroelectric crystals, the grain boundary effect cannot explain the perfect double P-E loop exists in the aged single-crystal sample, the domain-wall pinning effect cannot explain the restoration of the initial multidomain state from a single-domain state because there would be no domain wall to be dragged back, and the volume effect is based on a key assumption that there exist dipolar defects and they follow spontaneous polarization after aging (Zhang & Ren, 2005.…”

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

“…However, these OVs and the associated point defect polarization P D remain frozen in the original states during such an abrupt (diffusionless) domain-switching process [ Figs.3(a) to 3(b)]. [8][9][10] In such a diffusionless domain-switching process, this unswitched P D (black thin arrow) creates an internal field E 23,24 This reversible domain switching mechanism explains the completely constricted hysteresis loops observed under small applied electric fields for all aged acceptor-doped BaTiO 3 ceramics. The reason for the weaker aging effect under larger electric fields could be that during the larger field (large force on effectively positive-charged OVs) applying process, available energy is sufficiently high for a part of OVs short-range hopping [ Figs.3(a) to 3(c)].…”