Substitution of lead into the bismuth oxide layers of the n=2- and n=3-Aurivillius phases

Ceramic materials of the n = 2- and n = 3-Aurivillius phases of type Bi(2)SrM(2)O(9) and Bi4Ti3O12 were systematically substituted by Pb2+. The simultaneous charge compensated incorporation was performed for n = 2 with the nominal compositions Bi(2-x)Pb(x)Sr(1-x)La(x)M(2)O(9) and Bi(2-x)Pb(x)SrM(2-x)W(x)O(9) as well as for the single lead substituted systems Bi(2-x)Pb(x)SrM(2)O(9-delta) with M = Nb, Ta (0 less than or equal to x less than or equal to 1). For n = 3 the following groups of materials were synthesized: Bi4-xPbxTi3-xNbxO12, Bi2-xPbxLa2Ti3-xNbxO12, Bi2-xPbxSr2-xLaxTiNb2O12 (0 less than or equal to x less than or equal to 1) and Bi2Sr2-yPbyTiNb2O12 (0 less than or equal to y less than or equal to 2). The powder X-ray diffraction diagrams were single phased for all materials, thus exhibiting a solid solution behavior over the whole range of substitution but for the single lead substituted n = 2 systems. Structural investigations by X-ray powder diffractometry were carried out with different space groups and ordering schemes in order to verify the incorporation of the isoelectronic Pb2+ for Bi3+ in the bismuth oxide layers. A partially disordered distribution of La, Pb and Bi in Bi2-xPbxLa2Ti3-xNbxO12 and ordering effects of Ti/Nb in Bi2Sr2-yPbyTiNb2O12 were indicated. Copyright (C) 1997 Elsevier Science Ltd.