Optimization of Synthesis Conditions of Monoclinic Potassium Niobate (KNbO3) and its Effect on Morphology

Stoichiometric orthorhombic and monoclinic KNbO3 samples have been prepared through low temperature-time hydrothermal method. Optimized synthesis conditions for monoclinic KNbO3 have been found to be hydrothermal treatment of 15M precursor solution at 160 degrees C for 8h. Transformation of orthorhombic KNbO3 to monoclinic KNbO3 has been established through thermodynamic considerations. Further, successful synthesis of orthorhombic KNbO3 has also been achieved under moderated conditions. FESEM analyses of synthesized materials revealed that initially formed block-like structures either stack upon one another to form hierarchical morphology or join end to end to form rods. Observations have been substantiated through HRTEM, EDX, FTIR, and Raman spectra analyses.