Non-equilibrium strain relaxation noise in the relaxor ferroelectric (PbMg1/3Nb2/3O3)1-x(PbTiO3)x

Abstract

Large low-frequency polarization noise is found in some perovskite relaxor ferroelectrics when they are partially polarized, regardless of whether the polarization is accompanied by an applied electric field. The noise appears both in the ferroelectric and relaxor states, including the nominally ergodic paraelectric state at temperatures above the susceptibility peak. Since it is present whenever the samples have non-zero average piezoelectric coefficients, but not otherwise evident, it appears to be a response to mechanical strain changes. Dependence of the noise on sample thermal history indicates that non-equilibrium strain relaxation is the source, even in the temperature range for which the sample is nominally ergodic. Non-equilibrium noise in the absence of net piezoelectricity is found at somewhat higher frequencies. Related materials lacking a metastable non-equilibrium cubic bulk phase and a symmetry-broken surface layer show very little of the anomalous low-frequency noise. The implications for a non-equilibrium origin of the skin effect are discussed.

Defect‐Driven Structural Distortions at the Surface of Relaxor Ferroelectrics

“…[13] Skin structures have also been suggested to contribute to large lowfrequency polarisation noise observed in common relaxor ferroelectrics, having the potential to degrade the performance of sensitive acoustic transducers. [14] Skin structures may also have the potential to be functionalised in applications in future transistor technology [15] , voltage-controlled catalysis [16] and spintronics [4c] .…”