Properties of Ferroelectric Single Crystals in the System LixNa1-xNbO3

Abstract

Relatively large size single crystals of LixNa1-xNbO3 were grown by Czochralski method. Three compositions of x=0.09, 0.12 and 0.16 have been studied by X-ray diffraction, dielectric measurement and ferroelectric hysteresis loops. At room temperature, the point group of crystal of x=0.09 is mm2 and that for x=0.12 and 0.16 is 4 mm. From the temperature dependence of the dielectric constant and the hysteresis loops, the transition temperature Tc, Curie-Weiss temperature To, curie-Weiss constant C, spontaneous polarization Ps, coercive field Ec and the high field loss tangent tan δH were determined for each composition. The significant difference between Tc and T0 indicates the first order character of the ferro-paraelectric phase transitions. Crystals with x=0.12 shows the largest Ps and the lowest Ec which is ascribed to the morphotropic phase transition near room temperature for this composition.