Synthesis and crystallization pathway of Na 0.5Bi 0.5TiO 3 thin film obtained by a modified sol–gel route

Abstract

As a lead-free candidate for electronic application, Na 0.5Bi 0.5TiO 3 (NBT) thin films were produced by a 2-methoxyethanol sol–gel route and CSD method. Thermal decomposition and crystallization pathway of the alkoxide-based precursor have been studied by thermal analysis and X-ray diffraction (XRD) techniques. No transitory nanocrystalline phase was detected during the crystallization process of NBT. As a consequence, the nucleation of the stable perovskite phase occurred at low temperature (<500 °C). The parameters of the post-coating steps, i.e. drying and pyrolysis temperatures were chosen according to thermogravimetric data. Studies of the thermal annealing for crystallization are presented and discussed in terms of microstructure features from field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) observations.