Influence of porous configuration on dielectric and piezoelectric properties of KNN-BKT lead-free ceramic

Porous piezoelectric ceramics are the far and wide known graded functional materials. Of late, lead-free porous piezoelectric systems have increased enormous consideration, because of the factors inclusive of environmental friendly, light weight, low acoustic impedance and versatility. Porous lead-free (1-x) (K, Na) NbO3. x (Bi, K) TiO3 (KNN-BKT) solid solution, was synthesized by solid state method. The porogen utilized as part of this work was ammonium oxalate monohydrate in 10, 20, 30 and 40 wt% to get diverse porosity levels in the lead-free specimen. Primary evaluation of the porous specimen has been done with respect to its phase by XRD and surface microstructure using SEM. The specimens were poled and their piezoelectric coefficients were assessed at varied temperatures. Dielectric properties as a function of temperature and frequency are also reported for the specimens.