Potassium niobate (KNbO3) were successfully prepared by the solution processing through the reaction of aqueous H2O2 solution with niobium and potassium alkoxides. In this process, potassium and niobate peroxide formed as the precursor for KNbO3. Precursor powder crystallized into KNbO3 at a sintering temperature as low as 650 °C in oxygen. KNbO3 thin films comprised of uniform grains with dimension of around 100 nm were fabricated. © 2004 Elsevier B.V. All rights reserved.