Nonlinear dynamics of polar regions in paraelectric phase of (Ba1-x,Srx)TiO3 ceramics

TL;DR

This study investigates the nonlinear dielectric behavior of (Ba1-x,Srx)TiO3 ceramics in their paraelectric phase, revealing that their response resembles relaxor materials rather than Rayleigh-type dynamics.

Contribution

It provides new insights into the mechanisms of dielectric nonlinearity in (Ba1-x,Srx)TiO3 ceramics, challenging the applicability of Rayleigh models for these materials.

Findings

Nonlinear response resembles relaxor Pb(Mg1/3Nb2/3)O3.

Rayleigh-type dynamics are inadequate to explain the observed behavior.

Amplitude and phase analysis of harmonics used to characterize nonlinearity.

Abstract

The dynamic dielectric nonlinearity of barium strontium titanate (Ba1-x,Srx)TiO3 ceramics is investigated in their paraelectric phase. With the goal to contribute to the identification of the mechanisms that govern the dielectric nonlinearity in this family, we analyze the amplitude and the phase angles of the first and the third harmonics of polarization. Our study shows that an interpretation of the field-dependent polarization in paraelectric (Ba1-x,Srx)TiO3 ceramics in terms of the Rayleigh-type dynamics is inadequate for our samples and that their nonlinear response rather resembles that observed in canonical relaxor Pb(Mg1/3Nb2/3)O3.