The Aurivillius systems with high Curie temperature or fatigue-free are possible candidates for applications in high temperature piezoelectric devices or non-volatile ferroelectric random access memories. The structure of these materials is represented by the equation Am-1Bi2BmO3m+3 where m is the number of perovskite blocks between [Bi2O2]2+ layers. The SrBaBi2Nb2TiO12 ferroelectric material belongs to the Aurivillius family with m = 3. A previous structural study on this system, by using X-ray diffraction, has shown a tetragonal structure with space group I4/mmm at room temperature [1]. A cation sites mixing have been reported between A sites and bismuth sites into the [Bi2O2]2+ layered structure [1]. The present work shows the dielectric analysis for this material in a wide range of frequencies and temperatures. Two anomalies are observed in the temperature dependence of the real dielectric permittivity, one near room temperature and the other one at high temperature. By using X-ray diffraction and Raman spectroscopy, in a wide temperature range, both anomalies are studied in order to evaluate phase transitions or another cause for the observed behaviors, especially at room temperature.
References
[1] Haluska MS and Misture ST, J Solid State Chem. 177, 1965–1975 (2004).