The fine-grained KNN-LN ceramics densified from nanoparticles obtained by an economical sol-gel route

► Fine-grained KNN-LN lead-free piezoelectric ceramics have been densified at the temperature below 1000 °C using sol-gel derived nano-particles as precursor oxides. ► The phase structure of the (1 − x)KNN-xLN ceramics changed from orthorhombic to tetragonal at x = 0.08-0.10, and the large improvements in the piezoelectric properties were observed for 0.90KNN-0.10LN.