Temperature effect on phase formation of nanocrystalline bismuth titanate synthesized via hot injection method

Abstract

Nanocrystalline bismuth titanate materials were synthesized via hot injection method for the first time. Bismuth nitrate and titanium butoxide were used as precursors of Bi and Ti, respectively. The synthesis method was modified to use aqueous solution as the solvent instead of non coordinating solvent which enable production of nanosized compounds at lower reaction temperature. During the synthesis process, titanium precursor was injected into mixture of bismuth nitrate and oleic acid at 130°C, leading to a rapid burst nucleation and followed by nuclei growth at room temperature. The synthesized compound was heated at various temperatures. XRD results showed formation of cubic phase bismuth titanate compound with space group of Fm3m at room temperature after the reaction. Presence of cubic phase bismuth titanate compound with space group of I23 was observed as secondary phase at 300oC. Meanwhile, a single phase cubic form, space group I23 was obtained for material synthesized at 600oC. FESEM images indicated nano particles of bismuth titanate materials were produced at lower temperatures. However, sintering effect was observed in material heated at 600oC, resulting micro-sized particles.