Preparation of needle-like NaNbO3 by molten NaOH method

Needle-like NaNbO3 has been prepared in two steps by a molten NaOH method. First, Na-7(H3O)Nb6O19 center dot 14H(2)O precursor was synthesized by the reaction of Nb2O5 with a molten NaOH at 450 C for 50 h in air. The Na-7(H3O)Nb6O19 center dot 14H(2)O precursor was a needle-like single crystal 0.25-1.5 pm wide and >3 mu m long. Then, the Na-7(H3O)Nb6O19 center dot 14H(2)O precursor crystal transformed to NaNbO3 through an intermediate Na-7(H3O)Nb6O19 by a heating above 500 degrees C. The NaNbO3 was a needle-like polycrystal with a perovskite-type structure. (C)2010 The Ceramic Society of Japan. All rights reserved.