Electronic domain pinning in Pb(Zr,Ti)O3 thin films and its role in fatigue

Abstract

Switchable polarization can be significantly suppressed in Pb(Zr,Ti)O3 thin films by optical, thermal, and electrical processes. The optical (thermal) suppression effects occur by biasing the ferroelectric near the switching threshold and illuminating the material with band-gap light (heating the material to ≊100 °C). The electrical suppression effect, commonly known as electrical fatigue, occurs by subjecting the ferroelectric to repeated polarization reversals. It is found that the suppressed polarization in all three cases can be restored to essentially its initial polarization value by injecting electronic charge carriers into the ferroelectric. This strongly suggests that all three forms of degradation involve locking domains by electronic charge trapping centers.

Continuum thermodynamics of ferroelectric domain evolution: Theory, finite element implementation, and application to domain wall pinning

“…There is also evidence that the attractive "linear" properties of many ferroelectrics, such as high piezoelectric constants and large dielectric constants, is due to anelastic domain wall motion. The nature of domain walls and their interactions with other material defects is fundamental to the understanding of the physical phenomena associated with the finite coercive strength of ferroelectrics, fracture toughening associated with domain switching (Wang and Landis, 2004), and electrical fatigue associated with pinning of domain walls by migrating charge carriers (Warren et al, 1994;Xiao et al, 2005).…”

Cyclic electric field response of morphotropic Bi1/2Na1/2TiO3-BaTiO3 piezoceramics

“…Several mechanisms, 19,20 like microcracking, 21,22 drift of charge carriers, 23,24 and structural changes, 25 have been reported to contribute to fatigue. This investigation is focused on structural changes caused by electric cycling, which leads to material degradation and thus fatigue.…”

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

“…7,13,14 Generally speaking, all these mechanisms are based on the stabilization of domain patterns by defects. 7,[11][12][13][14][15] However, a unified microscopic explanation for all aspects of the FE aging effect is still a matter of debate.…”

“…[5][6][7][8][9][10] Previously, many mechanisms were proposed in order to explain these observed aging effects in ferroelectrics. Generally, there are three main mechanisms which are usually considered in the aging effect: (i) volume effect (formation and alignment of complex defect dipoles with respect to the direction of spontaneous polarization within FE domains in the course of time), 5,11 (ii) domain-wall pinning effect (migration of defects to the domain walls acting as pinning centers to lower the domain-wall energy), 12 and (iii) grain boundary effect (an intergranular second phase collecting space charges which is liquid at the sintering temperature and covers the grains as a thin layer). 7,13,14 Generally speaking, all these mechanisms are based on the stabilization of domain patterns by defects.…”