Charge migration in Pb(Zr,Ti)O3 ceramics and its relation to ageing, hardening and softening

Abstract

The dielectric response of hard (Fe-doped) and soft (Nb-doped) rhombohedral Pb(Zr0.58Ti0.42)1-xMexO3 (PZT; Me= Fe or Nb) ceramics was studied at subswitching conditions over a wide range of temperatures (50 C to 450 C) and frequencies (10 mHz to 10 kHz). The results show qualitative differences in behavior of the acceptor and donor doped samples. Hard materials exhibit a steep increase of the complex permittivity with decreasing frequency. The onset of the dispersion is thermally activated with activation energy of about 0.6-0.8 eV and is attributed here to oxygen vacancy hopping. Activation energy for ac conductivity observed in soft materials is estimated to about 1.7 eV, corresponding to the half of the energy gap of Pb(Zr,Ti)O3 and is thus consistent with electronic conduction. The relevance of ionic hopping conductivity in hard materials to ferroelectric aging / deaging and hardening is analyzed. Strong ionic conductivity in hard and its absence in soft samples agree well with the dipolar mechanism of ageing in hard materials and the absence of significant ageing in soft materials.

accepted in Journal of Applied Physics

References in corpus (7)

• A first-principles study of oxygen vacancy pinning of domain walls in PbTiO3
• Hardening-softening transition in Fe-doped Pb(Zr,Ti)O3 ceramics and evolution of the third harmonic of the polarization response
• The nature of iron-oxygen vacancy defect centers in PbTiO3
• Drift of charged defects in local fields as aging mechanism in ferroelectrics
• Separation of piezoelectric grain resonance and domain wall dispersion in PZT ceramics
• Space-charge mechanism of aging in ferroelectrics: an exactly solvable two-dimensional model
• Evidence for dielectric aging due to progressive 180 domain wall pinning in polydomain Pb(Zr0.45Ti0.55)O3 thin films

Cited by in corpus (7)

• Ferroelectric Polycrystals: Structural and microstructural levers for property engineering via domain-wall dynamics
• Role of charged defects on the electrical and electro-mechanical properties of rhombohedral Pb(Zr,Ti)O3 with oxygen octahedra tilts
• Multiscale Simulations of Defect Dipole-Enhanced Electromechanical Coupling at Dilute Defect Concentrations
• Oxygen vacancies in bulk and at neutral domain walls in hexagonal YMnO${}_3$
• Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields
• Identification of the defect distribution at ferroelectric domain walls from the evolution of nonlinear dielectric response during aging process
• Improving the Functional Control of Aged Ferroelectrics using Insights from Atomistic Modelling