Effects of molten salt content and reaction temperature on molten salt preparation of CaNaBi₂Nb₃O₁₂ powder

Pure bismuth layer-structured ferroelectric CaNaBi₂Nb₃O₁₂ ceramic powders with anisotropy were prepared by the molten salt method in molten salt fluxes of NaCI–KCl at 750–900 °C. The effects of salt content and calcination temperature on the microstructure and morphology of CaNaBi₂Nb₃O₁₂ powder were investigated. The phase and the microstructure of reaction products were detected by X-ray diffraction and scanning electron microscopy. The results show that the particle size of CaNaBi₂Nb₃O₁₂ powders and the level of anisotropy increase with increasing reaction temperature. The sample dispersion gets better with the increase of molten salt content. The CaNaBi₂Nb₃O₁₂ powders with good micromorphologies were obtained when the mass ratio of salt to raw materials is 1:1.05, calcined at 800 °C for 1 h. The grain is regularly flake-like, with uniform particle size and single good dispersion.