Study of dielectric and ferroelectric properties of five-layer Aurivillius oxides: A(2)Bi(4)Ti(5)O(18) (A = Ba, Pb and Sr) synthesized by solution combustion route

摘要

This paper presents the ferroelectric and dielectric properties of five-layer Aurivillius oxides (Ba2Bi4Ti5O18, Pb2Bi4Ti5O18 and Sr2Bi4Ti5O18) prepared by a solution combustion route with glycine as a fuel at low calcination temperature. The phase formation of these materials with pseudo-tetragonal structure was achieved after calcination at 750A degrees C for 3 h; as confirmed by X-ray diffraction studies. Scanning electron microscopy of the sintered ceramics shows that the grains exhibit a plate-like morphology. The ferroelectric to paraelectric transition temperature (T (c)) for Ba-, Pb- and Sr-based bismuth titanate ceramics was found to be 350, 280 and 260A degrees C, respectively. All three materials show multiple relaxation phenomena and their electrical conductivity was found to be temperature dependent. The Pb2Bi4Ti5O18 ceramic possessed the highest value of activation energy (0.68 eV) and hence shows better ferroelectric properties, as compared to barium and strontium bismuth titanates.