Structural and ferroelectric behavior of aurivillius related oxides Bi_2-xPb_xSrNb₂O_9-x/2 [formula omitted]

New substituted compounds of composition Bi2-xPbxSrNb2O9-x/2 ([formula omitted]) have been isolated as single phases, keeping the basic structure of the Aurivillius oxides. These materials were characterized by X-ray powder diffraction methods, at different temperatures up to 850 °C, showing crystallographic transformations which could be related with a ferroelectric behavior. Measurements of the dielectric constant ([formula omitted]) as a function of the temperature for x = 1 and x = 1.5 compositions show an anomalous behavior in the real component, that could confirm the existence of a phase transition. © 1994, Taylor & Francis Group, LLC. All rights reserved.