Ferroelectric Domain Structure and Local Piezoelectric Properties of Lead-Free (Ka0.5Na0.5)NbO3 and BiFeO3-Based Piezoelectric Ceramics

Abstract

Recent advances in the development of novel methods for the local characterization of ferroelectric domains open up new opportunities not only to image, but also to control and to create desired domain configurations (domain engineering). The morphotropic and polymorphic phase boundaries that are frequently used to increase the electromechanical and dielectric performance of ferroelectric ceramics have a tremendous effect on the domain structure, which can serve as a signature of complex polarization states and link local and macroscopic piezoelectric and dielectric responses. This is especially important for the study of lead-free ferroelectric ceramics, which is currently replacing traditional lead-containing materials, and great efforts are devoted to increasing their performance to match that of lead zirconate titanate (PZT). In this work, we provide a short overview of the recent progress in the imaging of domain structure in two major families of ceramic lead-free systems based on BiFeO3 (BFO) and (Ka0.5Na0.5)NbO3 (KNN). This can be used as a guideline for the understanding of domain processes in lead-free piezoelectric ceramics and provide further insight into the mechanisms of structure–property relationship in these technologically important material families.

Thickness Dependence of Ferroelectric and Optical Properties in Pb(Zr0.53Ti0.47)O3 Thin Films

“…Ranging in thickness from tens of nanometers to tens of microns, high quality PZT films are needed for a variety of applications [7]. Thus, the film thickness is a crucial factor affecting device performance besides some other factors including Zr/Ti ratio [8], annealing temperature [9], preparation method, and other factors [8,9,10,11,12,13,14]. Moreover, the thickness effect would become more pronounced when the films’ thickness vary from micrometer to nanometer scale [15].…”

Chemical Uniformity in Ferroelectric KxNa1−xNbO3 Thin Films

“…The weighted (integrated) area after peak deconvolution of KNN(002) and KNN(200) indicates a 1:15 ratio, meaning that ≈7% of the KNN crystallites are (100)‐oriented. This is not detrimental to function, however, the situation may nonetheless possibly be avoided by post‐annealing in an electric field …”

“…This is not detrimental to function, however, the situation may nonetheless possibly be avoided by post-annealing in an electric field. [24] We probed the piezo-/ferroelectric functionality of the KNN films by using in situ XRD (at SNBL@ESRF, Grenoble, France) upon perturbating the material by means of an electric field. The setup is described in a previous publication.…”

Study of domain configurations in (Bi,Na)ZrO3-modified (K,Na)(Nb,Sb)O3 piezoelectric ceramics by acid-etching at different temperatures

“…Each of these observation methods has its own advantages and shortcomings. Surface chemical etching bases on the different etching rates of the opposite polarities (the positive end and the negative end) of a polarizations dipole 7 – 10 . Aqueous solutions of HF, HCl and HNO 3 acids are often used as the etchant.…”