Effect of Sintering Temperature on the Structure and Piezoelectric Properties of Lead-Free 0.97K0.5Na0.5NbO3-0.03AlFeO3 Ceramics

Abstract

Lead-free piezoelectric 0.97 K0.5Na0.5NbO3-0.03 AlFeO3(KNN-AF) ceramics were prepared at low temperature of 980 °C to 1020 °C by the conventional ceramic process. The effect of sintering temperature on the crystal structure, density and electrical properties of the ceramics was investigated. The results indicate that KNN-AF ceramics sintered at an low temperature of 1000 °C exhibit high electrical and piezoelectric properties, with piezoelectric constantd33=116ρC/N, and electromechanical coupling factorkp= 32.9%, polarization (Pr) wasPr=21.8 μC/cm2and curie temperatureTC=382°C. This also indicates that KNN-AF ceramics are promising candidate materials for lead-free piezoelectric applications.