An aqueous solution-gel method for low temperature synthesis of nanocrystalline NaNbO3 and their ceramics

Nano-sized NaNbO3 powder has been successfully prepared by aqueous solution-gel method. The phase evolution of NaNbO3 powder is investigated by TG/DSC, X-rays spectra, FT-IR, and Raman spectra. The results show that the pure NaNbO3 phase has been obtained at about 375 A degrees C, which is lowered by about 100 A degrees C comparing to others' work. In TEM studied, it shows the average particle size of similar to 70 nm for the powders heat-treated at 750 A degrees C for 4 h. The powders heat-treated below 650 A degrees C for 4 h shows a Pmnm symmetry, then change from O-3 orthorhombic to O-1 orthorhombic with the heat-treatment temperature above 650 A degrees C.