Synthesis of Na_(0.5)Bi_(0.5)TiO_3 Submicron Particles in Molten Salt

摘要

Powder size is a major factor determining the characteristics of processing variables and end-products of ceramic materials. Na_(0.5)Bi_(0.5)TiO_3 is one of the potential candidates for non-lead piezoelectric materials, synthesis of Na_(0.5)Bi_(0.5)TiO_3 particles in molten salt was studied. Two salt systems, NaCl-KCl and Na_2SO_4-3K_2SO_4 were investigated. Only at 850°C and above, BNT was completely formed without any secondary phases in both eutectic chloride and sulfate salt. By substituting chloride with sulfate, the particle size of BNT could be greatly reduced to a few hundreds nanometer at 850°C. Submicron particles of SrTiO_3 could also be synthesized in eutectic sulfate salt at 850°C, It is evident that molten salt synthesis could be employed to produce submicron particles of Na_(0.5)Bi_(0.5)TiO_3 and SrTiO_3. Molten salt synthesis is low-cost and capable to produce fine powders of various complex-oxides.