Piezoelectric and electromechanical properties with textured NKLNT lead-free piezoelectric ceramics

Crystal-oriented 1-mol% Li2O-excess (Na0.51K0.47Li0.02)(Nb0.8Ta0.2)O3 (NKLNT) was manufactured from variously-sized NaNbO3 (NN) templates via reactive template grain growth. The effect of NN template size was investigated in regard to the degree of orientation and the piezoelectric properties of NKLNT. A planar NN template was prepared via the topochemical microcrystal conversion method, and its size was controlled by adding excess Na2CO3 to Bi2.5Na3.5Nb5O18 (BNN) precursor. The NN template size increased with the amount of Na2CO3 that was added to the BNN. The degree of orientation was high in tape-casted NKLNT, and its piezoelectric properties were considerably improved. The piezoelectric properties of oriented NKLNT varied with the NN template size, which was not exhibited in a non-oriented state, which state is related to the change in the degree of orientation. The results show that the template size has an effect on the degree of orientation and on the piezoelectric properties of oriented NKLNT.