Investigation of the Dielectric Properties of Antimony Doped Potassium Sodium Niobate Single Crystal (K<sub>0.5</sub>Na<sub>0.5</sub>) NbO<sub>3</sub> Grown by Flux Method

Abstract

Single crystals of K0.5Na0.5NbO3 (KNN) and 5wt%, 10wt%, 15wt% of Sb doped KNN crystals were grown by flux method. The formation of crystalline structure, microstructure, domain structure and the dielectric properties were investigated for both pure and Sb doped KNN single crystals. X-ray diffraction (XRD) pattern shows that pure and doped KNN single crystals have orthorhombic perovskite structure. The doped crystals have slight shrinkage in the unit cell volume. The partial substitution of the B-site ion Nb5+ by the Sb5+ ion in the KNN single crystal results in decreasing phase transition temperatures TO-T and Curie temperatures TC of the doped crystals with increasing amount of Sb. The dielectric properties of the doped crystals show significant improvement with doping concentration. The peaks slightly shift towards lower frequencies with increasing dopant concentration.