Dilatometric approach for the determination of the solid state reaction-onset of the lead based relaxor erroelectric system

Bhat, VV and Rao, Radhika MV and Umarji, AM (2003) Dilatometric approach for the determination of the solid state reaction-onset of the lead based relaxor erroelectric system. In: Materials Research Bulletin, 38 (6). pp. 1081-1090.

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Abstract

Dilatometer based thermal expansion studies have been carried out on the starting oxide mixtures of some of the important relaxor ferroelectric compositions including lead iron niobate, lead magnesium niobate–lead titanate and lead zinc niobate–barium titanate. An anomalous thermal expansion behavior is observed between $550\hspace{2mm}and\hspace{2mm}650^o\hspace{2mm}C$ corresponding to the onset of the solid state reaction. Further heating of the reaction mixture resulted in a decrease in the dimension of the sample. From the complementary evidence of DTA, X-ray diffraction (XRD) and scanning electron microscopy (SEM), it is shown that the initiation of solid state reaction results in the restructuring of the reacting grains to form the agglomerates of fine particles of reaction intermediates. This phenomenon is shown to be absent in the barium zinc niobate system where the pyrochlore intermediates do not exist. This novel dilatometric approach has been projected as a possible technique to identify optimum calcination temperatures to produce sinter-active powders in the above oxide system, thereby help in reducing the sintering temperatures.

Item Type:	Journal Article
Publication:	Materials Research Bulletin
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	A. Electronic materials;B. Chemical synthesis;D. Dielectric properties;D. Ferroelectricity;D. Thermal expansion
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	06 Jun 2006
Last Modified:	19 Sep 2010 04:29
URI:	http://eprints.iisc.ac.in/id/eprint/7534

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