Effect of B2O3 Flux on the Crystal Structure, Dielectric Properties of (K 0.5Na0.5)NbO3 Single Crystal Grown by Flux Method

Lead free piezoelectric single crystals of sodium potassium niobate (K 0.5Na0.5)NbO3 single crystals were grown by high-temperature solution method using B2O3 flux The KNN crystals grown by without B2O3 flux and with B2O3 flux are referred to as samples A and B respectively. It was found that additions of small amounts of boron oxide B2O3 further lower the melting temperature of the eutectic mixture and exhibits excellent dielectric properties. Phase analysis showed that all samples crystallized in pure orthorhombic perovskite phase. AFM morphological studies show that the root mean square (rms) roughness values were measured to be, 5.3nm and 6.96nm for the sample A and sample B crystal respectively. A slight decrease in the orthorhombic to tetragonal phase transition temperature TOT> and Curie temperature Tc has been observed in sample B when compared with sample A.