文摘
Systematic investigation on phase transition, dielectric and piezoelectric properties of (1-x)K0.5Na0.5Nb0.997Cu0.0075O3-xSrZrO3 (x = 0, 0.03, 0.06, 0.09, 0.12, 0.15, abbreviated as KNNC-100xSZ) ceramics was carried out. Due to the coexistence of orthorhombic and tetragonal phase in a wide temperature range, a diffused polymorphic phase transition (PPT) region was achieved in KNNC with x ≥ 0.06. KNNC-12SZ ceramics exhibited high dielectric permittivity (∼1679), low dielectric loss (∼0.02) and small variation (Δe'/ε'25 °C ≤ 15%) in dielectric permittivity from −78 °C to 237.3 °C. KNNC-6SZ ceramic possessed a high level of unipolar strain (∼0.15%) and maintained a smaller variation of ±12% under the corresponding electric field of 60 kV cm−1 at 10 Hz from 25 °C to 175 °C. d33*, which was calculated according to the unipolar strain at 60 kV cm−1, was 230 pm V−1 and remained stable below 100 °C. Therefore, our work provided a new promising candidate for temperature-insensitive capacitors and piezoelectric actuators.