Impedance spectroscopy and piezoresponse force microscopy analysis of lead-free (1 − x) K0.5Na0.5NbO3 − xLiNbO3 ceramics

► XRD studies showed the transition from orthorhombic to tetragonal above x = 5.5 wt.% of LN. ► Bulk or grain conduction up to 400 °C. ► Grain boundary conduction up to 450 °C. ► Electrical conduction in KNLN is mainly due to the mobility of the ionized oxygen defects. ► With 6.5 wt.% LN displays stronger piezocontrast as compared to pure KNN.