Reaction mechanism of perovskite KNbO3 in aqueous solution

Nanosize particles of potassium niobate KNbO3 were prepared by a soft chemistry method. A rock-salt-type KF block in a layered perovskite, K2NbO3F, was selectively dissolved in water to produce a colloidal solution containing niobate nanosheets at room temperature. Self-assembly of the nanosheets in the colloidal solution provides ultrafine particles of potassium niobate. Crystal structure of soft chemical KNbO3 was determined by Rietveld refinement method for neutron diffraction patterns. The refinement indicates that the product by this soft chemical method crystallizes an orthorhombic system with space group Amm2 (No. 38) and lattice parameters with a = 0.39906(6), b = 0.5688(l) and c = 0.5698(l) nm.