CuO-added 0.96(Na0.5K0.5)(Nb1- xSbx)O3-0.04SrTiO3 ceramics sintered at the low temperature of 960°C for 10 hours showed dense microstructures and high relative densities. The specimens with 0.0 ≤ x ≤ 0.04 had orthorhombic-tetragonal polymorphic phase boundary (PPB) structure. Tetragonal-pseudocubic PPB structure was observed in specimens with 0.05 ≤ x ≤ 0.07, while the specimen with x = 0.08 has a pseudocubic structure. The structural variation in the specimens is explained by the decreases in the orthorhombic-tetragonal transition temperature and Curie temperature with the addition of Sb5+ ions. The specimens with 0.05 ≤ x ≤ 0.07, which have tetragonal-pseudocubic PPB structure, had large electric field-induced strains of 0.14%-0.016%. Moreover, these specimens also showed increased d33 values between 280 pC/N and 358 pC/N. In particular, the specimen with x = 0.055 showed particularly enhanced piezoelectric properties: d33 of 358 pC/N, kp of 0.45, and the electric field-induced strain of 0.16% at 4.5 kV/mm.
Bibliographical noteFunding Information:
This research was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20152020104960). This work was also supported by the KU-KIST Graduate School of Converging Science and Technology Program.
© 2018 The American Ceramic Society
- lead-free ceramics
- phase transition
- piezoelectric materials/properties
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry