Investigation of polarization switching in (001)c, (110)c, and (111)c oriented Pb(Zn1/3Nb2/3)O3–4.5%PbTiO3 crystals

Abstract

The dynamics of polarization switching have been investigated over extremely broad time (10−8<t<102 s) and field ranges for (001)c, (110)c, and (111)c-oriented Pb(Zn1/3Nb2/3)O3–4.5%PbTiO3 crystals. The results demonstrate the presence of broad relaxation time distributions that can extend over a decade(s) in orders of magnitude in time, and which sharpen significantly with increasing field. The polarization transients have been fit to stretched exponential functions, which are typical of disordered systems.

Frequency dependence of the coercive field of 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 single crystal from 0.01 Hz to 5 MHz

“…The dynamics of polarization switching had been investigated over extremely broad time scale (10 À8 < t <10 2 s) and field ranges for various modified Pbbased perovskite ferroelectrics. 22 The results unambiguously demonstrated the presence of extremely broad relaxation time distributions for switching and the existence of multiple regions in the time domain near E c . Stretched exponential functions 22,31 had been used to fit current transients and more than one average relaxation time (i.e., short-time, intermediate-time, and long-time relaxation times) were found.…”

“…22 The results unambiguously demonstrated the presence of extremely broad relaxation time distributions for switching and the existence of multiple regions in the time domain near E c . Stretched exponential functions 22,31 had been used to fit current transients and more than one average relaxation time (i.e., short-time, intermediate-time, and long-time relaxation times) were found. This strongly suggests the fact that heterogeneous nucleation (nucleation of polar nanoregions 31,32 ) occurring in the vicinity of defects and/or random fields plays an important role during polarization switching.…”

“…1,11 In recent years, different scaling regions of E c vs f b were observed in ferroelectric thin films, [16][17][18][19] but the reason for these different scaling regions is still a debating issue. There are numerous investigations on polarization switching in the time domain, [20][21][22][23] which is related to our results in the frequency domain. In particular, an investigation of Pb-based piezoelectric crystals also demonstrated the presence of multiple regions in the time domain, in particular near E c .…”

“…Following the explanation in Ref. 22, it may be inferred that when the frequency of the bipolar electric field was larger than 1.0 MHz, the process of intermediate-time and long-time transient polarization switching could not happen in the PMN-0.29PT single crystal samples. As a result, a larger electric field will be needed to increase the domain-switching rate of short-time polarization transients, which may also be partially responsible for the change of b in Fig.…”

“…In particular, an investigation of Pb-based piezoelectric crystals also demonstrated the presence of multiple regions in the time domain, in particular near E c . 22 The relaxor-based (1-x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 (PMN-PT) ferroelectric single crystals have been extensively investigated owing to their giant piezoelectric coefficient, ultrahigh electromechanical coupling factor, large dielectric constant, and low dielectric loss. More complete picture about the superior functional properties can be seen from the complete set of elastic, piezoelectric, and dielectric constants.…”