# Preparation of $PbZrO_3/ASO_4$ Composites (A=Ca, Sr, Ba) and $PbZrO_3$ by Metathetic Reactions in the Solid State: Metathetic Exchange of Divalent Species

Panda, Monalisa and Seshadri, Ram and Gopalakrishnan, J (2003) Preparation of $PbZrO_3/ASO_4$ Composites (A=Ca, Sr, Ba) and $PbZrO_3$ by Metathetic Reactions in the Solid State: Metathetic Exchange of Divalent Species. In: Chemistry of Materials, 15 (7). pp. 1554-1559.

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## Abstract

Metathetic solid-state reactions of alkaline earth perovskite zirconates $(AZrO_3, A=Ca, Sr, Ba)$ and lead sulfate $(PbSO_4)$ result in the relatively quick formation of perovskite $PbZrO_3$ and the corresponding alkaline earth sulfate $ASO_4$ at temperatures as low as 1023K. The product can be described as a composite dispersion of small (<300 nm) particles of $PbZrO_3$ on larger crystals of the alkaline earth sulfates. The solid-state reaction at 973 K between $ZrO_2, PbSO_4,\hspace{2mm}and\hspace{2mm}K_2CO_3$ followed by washing in water to remove K2SO4 provides a quick route to submicron $(<1 {\mu}m)\hspace{2mm}PbZrO_3$ powders starting from inexpensive precursors. In all the reactions, we believe the driving force to be the high enthalpy of formation of $ASO_4\hspace{2mm}or\hspace{2mm} K_2SO_4$. The reactions presented here provide proof of concept for the preparation of a number of important polar lead-based perovskite phases under relatively mild conditions: (i) as composites, (ii) as small particles, and (iii) possibly as porous monoliths.

Item Type: Journal Article Copyright of this article belongs to American Chemical Society. Division of Chemical Sciences > Solid State & Structural Chemistry Unit 23 Jun 2006 19 Sep 2010 04:29 http://eprints.iisc.ernet.in/id/eprint/7681