0.96(Na0.5K0.5)(Nb1−xSbx)-0.04SrZrO3 ceramics with 0.0≤x≤0.06 were well sintered at 1060°C for 6 hours without a secondary phase. Orthorhombic-tetragonal transition temperature (TO -T) and Curie temperature (TC) decreased with the addition of Sb2O5. The decrease in TC was considerable compared to that in TO -T, and thus the tetragonal phase zone disappeared when x exceeded 0.03. Therefore, a broad peak for orthorhombic-pseudocubic transition as opposed to that for orthorhombic-tetragonal transition appeared at 115°C-78.2°C for specimens with 0.04≤x≤0.06. An orthorhombic structure was observed for specimens with x≤0.03. However, the polymorphic phase boundary structure containing orthorhombic and pseudocubic structures was formed for the specimens 0.04≤x≤0.06. Furthermore, a specimen with x=0.055 exhibited a large piezoelectric strain constant of 325 pC/N, indicating that the coexistence of orthorhombic and pseudocubic structures could improve the piezoelectric properties of (Na0.5K0.5)NbO3-based lead-free piezoelectric ceramics.
|Number of pages||9|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 2017 Oct|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry