MOLTEN-SALT SYNTHESIS OF A COMPLEX PEROVSKITE, PB(FE0.5NB0.5)O3

Pure, single-phase stoichiometric Pb(Fe0.5Nb0.5)O3 (PFN) powders were successfully formed by molten salt synthesis using mixtures of NaCl and KCl salts. Lower temperatures and shorter times (1/2 h at 800-degrees-C) were needed for single-phase PFN formation from molten salts relative to those required for solid-phase methods (4 h at 1000-degrees-C). A systematic study indicating the effects of process parameters, such as temperature, time, and amount of flux with respect to starting oxides, on the PFN formation mechanism and its resulting powder characteristics is reported. The particle size increased with increasing synthesis temperature; the rate of increase was greatest above 900-degrees-C, which is close to the melting point of PbO. PFN powders formed by molten salt synthesis are spheroidal, free from aggregates, and sintered to good densities at temperatures as low as 1000-degrees-C.