Kumar, Ranjit and Zulfequar, M. and Singh, V. N. and Tawale, J. S. and Senguttuvan, T. D (2012) Microwave sintering of dielectric CaCu3Ti4O12: An interfacial conductance and dipole relaxation effect. Journal of Alloys and Compounds, 541. 428-432. ISSN 0925-8388

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Abstract

A correlation between the microstructure and dielectric properties of microwave sintered CaCu3Ti4O12 (CCTO) ceramic was studied as a function of sintering temperature, frequency and measurement temperature. CaCu3Ti4O12 dielectrics ceramic were prepared by solid-state reaction route. Pellets were sintered for 15 min at 1000-1075 degrees C at an interval of 25 degrees C using microwave furnace operated at 2.45 GHz frequency, 8.8 kW power. XRD pattern revealed the formation of cubic perovskite CaCu3Ti4O12. The SEM micrographs show grain growth and reduction in porosity of the pellets on increasing the sintering temperature. The grains are cuboid shaped having well polished edges. Dielectric properties increase with increasing sintering temperature. The influence of conductivity across the barriers at grain and grain boundary are observed in the cole-cole plot. An improved conductivity or enhanced dielectric loss with respect to sintering temperature was observed at high frequencies. It is found that the grains dipole relaxation time increases, but the grain boundaries dipole relaxation time deceases with increasing sintering temperature. When the measurements were made at temperature greater than 40 degrees C, relaxation peaks of grain and grain boundary merged into single relaxation peak. Such relaxation leads to the minimum dielectric loss.

Item Type:	Article
Additional Information:	copyright for this article belongs to M/s Elsevier
Subjects:	Chemistry > Physical Chemistry Metallurgy & Metallurgical Engineering
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	19 Aug 2026 11:08
Last Modified:	19 Aug 2026 11:08
URI:	https://npl.csircentral.net/id/eprint/3491

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