Grain Size Effect on the Dielectric Properties of Molten Salt Synthesized BaTiO_3

摘要

In this report phase pure nanosize BaTiO_3 powder are prepared by molten salt method in the temperature range of 175-700℃, 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 BaTiO_3 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℃. 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 BaTiO_3 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.