Hardening-softening transition in Fe-doped Pb(Zr,Ti)O3 ceramics and evolution of the third harmonic of the polarization response

TL;DR

This study investigates how the third harmonic of polarization response in Fe-doped PZT ceramics reveals aging and deaging processes, showing significant phase shifts linked to charge migration mechanisms.

Contribution

It introduces the use of the third harmonic phase angle as a sensitive indicator of aging states and mechanisms in hard ferroelectric ceramics.

Findings

delta3 changes by 90 degrees during hardening-softening transition

delta3 evolution indicates participation of short- and long-range charge migration

Deageing involves multiple charge migration mechanisms

Abstract

It is shown that the phase angle of the third harmonic of polarization response (delta3) is very sensitive to the ageing state of hard, Fe-doped lead zirconate titanate [Pb(Zr,Ti)O3 or PZT] ceramics and may thus provide rich information on processes responsible for ageing in hard ferroelectrics. When hard PZT ceramics experience hardening (aged state) - softening (deaged state) transition, delta3 changes by about 90 degrees at subswitching fields and by about 180 degrees at switching conditions. Evolution of delta3 with time, temperature and electric field amplitude during deageing suggests that at least two mechanisms of charge migration, one short-range and one long-range, may participate in the deageing process.