Contribution of Bi0.5Na0.5ZrO3 on phase boundary and piezoelectricity in K0.48Na0.52Nb0.96Sb0.04O3-Bi0.5Na0.5SnO3-xBi0.5Na0.5ZrO3 ternary ceramics

In this work, we have attained a large piezoelectricity (d33 ∼468 pC N−1) in (0.9925-x)K0.48Na0.52Nb0.96Sb0.04O3-0.0075Bi0.5Na0.5SnO3-xBi0.5Na0.5ZrO3 (abbreviation: KNNS-BNS-xBNZ) ternary ceramics, prepared by a conventional solid-state reaction method. We illuminated the role of BNZ on the phase boundary and piezoelectric properties of the ceramics. Rhombohedra-orthorhombic-tetragonal (R-O-T) phase coexistence can be developed by controlling BNZ content, and then a high d33 value of ∼468 pC N−1 can be attained in the ceramics with x = 0.03. This result indicates that a higher d33 value can be attained by forming a new phase boundary using the addition of BNZ with respect to those of 0.9925K0.48Na0.52Nb0.96Sb0.04O3-0.0075Bi0.5Na0.5SnO3 ceramics with an orthorhombic phase. In addition, the maximum value both strain and d33∗ are all obtained at x = 0.04 (strain ∼0.18% and d33∗ ∼440 pm/V), which means that optimum BNZ content can enhance the strain and d33∗ of the ceramics. As a result, the ternary ceramic system may become one of the most promising candidates for the practical applications of KNN-based materials.