An alternative approach of solid-state reaction to prepare nanocrystalline KNbO₃

Author： Su Tingting Jiang Heng Gong Hong Zhai Yuchun

ISSN： 0022-2461

Source： Journal of Materials Science, Vol.45, Iss.14, 2010-07, pp. : 3778-3783

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

A simple preparation of KNbO₃ powders was proposed by an alternative approach of solid-state reaction. Stoichiometric niobium oxalate and potassium acetate were mixed in water and then dried. It was demonstrated that an ion-exchange reaction occurred with the formation of K[NbO(C₂O₄)₂]·nH₂O intermediate. The single-phase KNbO₃ powders were synthesized when K[NbO(C₂O₄)₂]·nH₂O intermediate was calcined between 500 and 800 °C for 3 h. KNbO₃ powders obtained at 500 °C are determined as orthorhombic structure with an average particle size of 20–50 nm by X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscopy (TEM) analysis. The morphologies of KNbO₃ obtained at different temperatures were observed by SEM and TEM analysis. The average band gap energy is estimated to be 3.16 eV by UV–vis diffuse reflectance spectra.