Microstructure, piezoelectric, ferroelectric and dielectric properties of Na0.5K0.5NbO3single crystals prepared by seed-free solid-state crystal growth

The Na0.5K0.5NbO3 single crystal was successfully grown by a seed-free solid-state crystal growth method using super-low content of LiBiO3 as a sintering aid. Microstructure, piezoelectric, ferroelectric and dielectric properties were investigated. The results show that well-paralleled lamellar ferroelectric ordering domains structure are present and no crack can be seen inside the single crystal. The best piezoelectric and dielectric properties (at 1 kHz) of d33 = 265 pC/N, Pr = 27.4 μC/cm2, e = 738, tanδ = 0.04 appear at x = 0.40at% for (1-x)Na0.5K0.5NbO3-xLiBiO3 single crystal. A higher remnant polarization Pr of 36.3 μC/cm2 were obtained at x = 0.45 at%.