Tabular Sr₃Ti₂O₇ intermediates synthesized by molten salt method

Using SrCO₃ and TiO₂ as raw materials, the tabular intermediates Sr₃Ti₂O₇ was synthesized by molten salt method. The phase composition and microstructure of these powders were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of molten salt (NaCl and KC1), reactive temperature and reactive time on the synthesis of tabular intermediates Sr₃Ti₂O₇ were discussed in this paper. The results showed that the intermediates obtained by using KC1 as molten salt were composed of anisotropic Sr₃Ti₂O₇ and Sr₂ TiO₄. The intermediates obtained by using NaCl as molten salt were composed of anisotropic Sr₃Ti₂O₇, Sr₂ TiO₄ and Sr₄Ti₃O₁₀. There have little effect on phase composition and phase contents by using excessive SrCO₃ or improving synthesis temperature. Moreover, by using excessive SrCO₃ or improving synthesis temperature, the contents of Sr₃Ti₂O₇ increase, but that of Sr₂TiO₄ decreases. The intermediates obtained at 1300°C for 4 h by using NaCl as molten salt were rectangle and tabular, its edge length and thickness is 30-60 μm and 2-5 μm respectively, which is the idea template for epitaxial growth of <001>SrTiO₃ tabular crystals. However, the intermediates obtained by using KCl as molten salt were also rectangle and tabular, its edge length and thickness is 10-20 μm and 5-10 μm.