Large-scale synthesis of Pb1−xLaxTiO3 ceramic powders by molten salt method

The ferroelectric perovskite type lanthanum doped lead titanate (PLT) ceramic powders were synthesized in one step with the starting materials of PbC₂O₄, La₂O₃ and TiO₂ in NaCl–KCl molten salts in the temperature range of 700–950 °C. It was found that molten salt method was a large scale and easy preparation way to produce PLT powders with high dispersity. Tetragonal phase Pb_1?xLa_xTiO₃ ceramic powders were identified by XRD in the composition range 0 ≤ x ≤ 0.3 and mono-dispersed particles with spheric shape and less than 100 nm size were observed by SEM. The grain sizes of Pb_1?xLa_xTiO₃ ceramic powders increased with the increase of La content and decreased with calcination temperature. The grain growth progress and the possible reaction mechanism in molten salts and its influencing factors were discussed in this work. The grain growth process was the main influencing factor of the grain size, which depended on the solubility in the flux.