Grain Size Effect on the Dielectric Properties of Molten Salt Synthesized BaTiO3

In this report phase pure nanosize BaTiO3 powder are prepared by molten salt method in the temperature range of 175-700 degrees C, which is much lower than that of the conventional preparation method. Two molten salt systems, namely NaCl-KCl and NaOH-KOH have been exploited to prepare BaTiO3 powder. Effect of two salt systems on the purity, size, shape and morphology of the as obtained products were studied. It has been found that as synthesized powder can be sintered at a temperature as low as 1225 degrees C. Interestingly, the grain size in the sintered product found to be 200-500 nm. Interestingly, the dielectric property of such low-temperature sintered samples is on a par with BaTiO3 samples prepared via conventional sintering at a high temperature. The percent change in dielectric constant around Curie peak found to be less than five percent for NaOH-KOH molten salt system. The Curie peak height and width is strongly depends upon the grain size of the sample.