Sol–gel synthesis and characterization of lead-free LNKN nanocrystalline powder

A kind of lead-free nanocrystalline powder, (Li0.06Na0.47K0.47)NbO3 (LNKN), has been prepared by a newly developed sol–gel method using Nb2O5 as the Nb source. Phase analysis, microstructure and morphology of the powder were determined by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman, transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM). The experimental results showed that pure perovskite phase was formed at the temperature as low as 500 °C. Besides, the obtained powder belonged to tetragonal symmetry, and the mean particle size was as small as 20 nm. It is believed that the high-quality gel precursor and low processing temperature play a key role in the formation of the LNKN nano-particles. The process developed in this work was convenient to realize the mass production of LNKN nano-powders at low cost.