Preparation of KNbO3 nanocubes using a solvothermal method at low temperature

Abstract

Potassium niobate (KNbO3) was prepared using a solvothermal method. The synthesis was conducted using niobium oxide (Nb2O 5) and potassium hydroxide (KOH) as starting materials and ethanol as the reaction medium. X-ray diffraction (XRD) confirmed the presence of perovskite KNbO3 particles and indicated that the lattice of the KNbO3 was orthorhombic. The morphology of the KNbO3 was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). Energy-dispersive X-ray (EDX) spectrometry was conducted with TEM/STEM, which clearly revealed that the KNbO3 particles were nanosized and possessed a cubic shape with sharp-edged corners. The STEM-EDX observations indicated that all three elements of potassium (K), niobium (Nb), and oxygen (O) were distributed homogeneously across the nanocubes. Only K, Nb, and O were detected in the EDX spectrum of the KNbO3 powders obtained. Thus, KNbO3 nanocubes were successfully prepared using a solvothermal method at low temperature. © 2013 The Ceramic Society of Japan.