Anomalous change in leakage and displacement currents after electrical poling on lead-free ferroelectric ceramics

TL;DR

This study investigates how electrical poling affects leakage and displacement currents in lead-free ferroelectric ceramics, revealing significant improvements in electrical properties and polarization behavior due to domain and defect modifications.

Contribution

It demonstrates the impact of electrical poling on leakage current reduction and polarization enhancement in Al-doped NBT-BT ceramics, highlighting the underlying defect and domain dynamics.

Findings

Leakage current decreased by nearly three orders of magnitude after poling.

Poling improved polarization saturation and transformed polarization loops.

Domain pinning and charge trapping are neutralized by poling.

Abstract

We report the polarization, displacement current and leakage current behavior of a trivalent nonpolar cation Al cation substituted lead free ferroelectric NBT-BT electroceramics with tetragonal phase and P4mm space group symmetry. Nearly three orders of magnitude decrease in leakage current were observed under electrical poling, which significantly improves microstructure, polarization, and displacement current. Effective poling neutralizes the domain pinning, traps charges at grain boundaries and fills oxygen vacancies with free charge carriers in matrix, thus saturated macroscopic polarization in contrast to that in upoled samples. E-poling changes bananas type polarization loops to real ferroelectric loops.