Abstract
The Nb-peroxo compound aqueous solution was prepared by peptization of niobic acid precipitate with hydrogen peroxide. The heat treatment of the Nb-peroxo compound aqueous solution at 348 K for 24h formed crystallized Nb2O5 nanoparticles. Potassium nitrate was dissolved into the Nb-peroxo compound solution, which was dried at 573 K to obtain the oxide complex containing K+ and Nb5+ ions. When the complex was fired at 873 K for 1h, single perovskite phase of KNbO3 was obtained. In the case that the Nb-peroxo complex was used as the precursor for preparation of KNbO3, the Raman spectra indicated that the obtained KNbO3 had the tetragonal structure which is the high pressure phase. The UV-VIS spectra and the lattice parameter of the obtained KNbO3 from the Nb-peroxo complex showed the presence of defect structures which can not be obtained by ordinary powder process.
