Structural Contribution to the Ferroelectric Fatigue in Lead Zirconate Titanate (PZT) Ceramics

TL;DR

This study reveals that ferroelectric fatigue in PZT ceramics near the MPB is caused by a less effective tetragonal-to-monoclinic phase transformation, leading to polarization degradation observed through synchrotron x-ray diffraction.

Contribution

It provides direct structural evidence linking ferroelectric fatigue to phase transformation inefficiencies in doped PZT ceramics near the MPB.

Findings

Fatigue arises from less effective tetragonal-to-monoclinic transformation.

Degradation of polarization is linked to diffuse anomalies in lead atomic displacement.

Time-resolved data confirms structural changes occur within 250 μs.

Abstract

Many ferroelectric devices are based on doped lead zirconate titanate (PZT) ceramics with compositions near the morphotropic phase boundary (MPB), at which the relevant material's properties approach their maximum. Based on a synchrotron x-ray diffraction study of MPB PZT, bulk fatigue is unambiguously found to arise from a less effective field induced tetragonal-to-monoclinic transformation, at which the degradation of the polarization flipping is detected by a less intense and more diffuse anomaly in the atomic displacement parameter of lead. The time dependence of the ferroelectric response on a structural level down to 250 $\mu$s confirms this interpretation in the time scale of the piezolectric strain response.