High performance' lead-free piezoelectric 0.96(K0.48Na0.52)NbO3-0.03[Bi0.5(Na0.7K0.2Lioi)0.5]ZrO3-0.01(Bi0.5Na0.5)TiO3 single crystals grown by solid state crystal growth and their phase relations

0.96(K0.48Na0.52)NbO3-0.03[Bi-0.5(Na0.7K0.2Li0.1)(0.5)]ZrO3-0.01(Bi0.5Na0.5)TiO3 single crystals were grown for the first time by the solid state crystal growth method, using [001] or [110]-oriented KTaO3 seed crystals. The grown single crystal shows a dielectric constant of 2720 and polarization-electric field loops of a lossy normal ferroelectric, with P-r = 45 mu C/cm(2) and E-c =14.9 kV/cm, while the polycrystalline samples with a dielectric constant of 828 were too leaky for P-E measurement due to humidity effects. The single crystal has orthorhombic symmetry at room temperature. Dielectric permittivity peaks at 26 degrees C and 311 degrees C, respectively, are attributed to rhombohedral-orthorhombic and tetragonal-cubic phase transitions. Additionally, Raman scattering shows the presence of an orthorhombic-tetragonal phase transition at similar to 150 degrees C, which is not indicated in the permittivity curves but by the loss tangent anomalies. A transition around 700 degrees C in the high temperature dc conductivity is suggested to be a ferroelastic-paraelastic transition. (C) 2017 Elsevier Ltd. All rights reserved.