Low temperature synthesis of plate-like Na0.5Bi0.5TiO3 via molten salt method

In this study, plate-like Na 0.5 Bi 0.5 TiO 3 (BNT) templates with perovskite structure were obtained by two-step molten salt synthesis (MSS) method at a low temperature. Firstly, Bi 4 Ti 3 O 12 precursors were synthesized at 1030 °C in NaCl–KCl molten salt. Secondly, plate-like Na 0.5 Bi 0.5 TiO 3 particles with perovskite structure were obtained from plate-like layer-structured ferroelectric ceramic of Bi 4 Ti 3 O 12 by topochemical microcrystal conversion method. Result showed that excessive Na 2 CO 3 was beneficial to facilitate the low temperature synthesis. In the case of an excess of 30 mol% Na 2 CO 3 , plate-like BNT particles could be obtained by synthesis at temperatures ranging from 760 °C to 800 °C, which indicated a flexible processing route. Also, it has been observed that plate-like BNT particles show a high aspect ratio with 1 μm in thickness and 10–20 μm in length. These Na 0.5 Bi 0.5 TiO 3 plate-like particles can be good candidates for the preparation of lead-free BNT-based piezoelectric ceramics with oriented grain microstructure.