Enhancement of electromechanical properties in lead?free (1?x)K0.5Na0.5O3?xBaZrO3 piezoceramics

Abstract

This study analyzes the phase transition behavior and electrical properties of lead-free (1?x)K0.5Na0.5NbO3?xBaZrO3 (KNN?100xBZ) piezoelectric ceramics. The stabilized crystal structures in BaZrO3-modified KNN ceramics is clarified to be pseudocubic. The polymorphic phase transition from the orthorhombic to pseudocubic phases can be observed with KNN?6BZ ceramics considering the optimized piezoelectric constant (d33). Electromechanical strain behaviors are discussed. Accordingly, the enhancement of strain value at x = 0.08 (composition) may originate from the coexistence of ferroelectric domains and polar nanoregions. A schematic of domains for KNN, KNN?8BZ, and KNN?15BZ ceramics has been proposed to describe the relationship between the stabilized relaxor and changes in electrical properties.