Preparation and characterization of K Nb O3 from a precursor obtained by reaction between oxalates in solution

Ammonium di-hydrogen tris (oxalato) oxo niobate (V) tri hydrate in reaction with potassium oxalate in a solution of oxalic acid and ammonium oxalate, leads to the precursor by evaporation. This precursor when heated yields K Nb O 3. The method of preparation of a precursor allows an improved homogeneity and lower calcination temperature. This method leads to a better control of the reagents, elimination of phases and preparation of single-phase orthorhombic K Nb O 3 characterized by X-ray diffraction, I.R. spectroscopy and chemical analysis. (author)