Effect of sintering conditions on the microstructural, dielectric,ferroelectric and varistor properties of $CaCu_3Ti_4O_{12}$ and $La_{2/3}Cu_3Ti_4O_{12}$ ceramics belonging to the high and low dielectric constant members of $ACu_3M_4O_{12}$ (A = alkali, alkaline-earth metal,rare-earth metal or vacancy, M = transition metal) family of oxides

Prakash, Shri B and Varma, KBR (2008) Effect of sintering conditions on the microstructural, dielectric,ferroelectric and varistor properties of $CaCu_3Ti_4O_{12}$ and $La_{2/3}Cu_3Ti_4O_{12}$ ceramics belonging to the high and low dielectric constant members of $ACu_3M_4O_{12}$ (A = alkali, alkaline-earth metal,rare-earth metal or vacancy, M = transition metal) family of oxides. In: Physica B: Condensed Matter, 403 (13-16). pp. 2246-2254.

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Abstract

Effect of sintering conditions on the microstructural, dielectric, ferroelectric (FE) and varistor properties of $CaCu_3Ti_4O_{12}$ and $La_{2/3}Cu_3Ti_4O_{12}$ ceramics belonging to the high and low dielectric constant members of $ACu_3M_4O_{12}$ (A = alkali, alkaline-earth metal,rare-earth metal or vacancy, M = transition metal) family of oxides was investigated in detail and a comparison was made. While sintering conditions had an imprinting effect on the physical properties of $CaCu_3Ti_4O_{12}$ ceramic, these have minimal influence on the $La_{2/3}Cu_3Ti_4O_{12}$ ceramic. Contrary to the previous observations that the $CaCu_3Ti_4O_{12}$ and the other oxides of the family belong to the centrosymmetric space group Im3, both $CaCu_3Ti_4O_{12}$ and $La_{2/3}Cu_3Ti_4O_{12}$ ceramics exhibited FE hysteresis loops with remnant polarization and coercive field values depending strongly on sintering conditions. The dc bias studies suggested that the electric field had significant effect on resistance and capacitance of grain and the grain boundary in $CaCu_3Ti_4O_{12}$, whereas it had only subtle effect in the case of $La_{2/3}Cu_3Ti_4O_{12}$. $CaCu_3Ti_4O_{12}$ exhibited strong nonlinear current–voltage characteristics and the electric field at which nonlinearity sets in decreased with increase in the sintering duration. On the contrary, all $La_{2/3}Cu_3Ti_4O_{12}$ samples under study exhibited linear current–voltage behavior in the entire voltage range of measurement, irrespective of the sintering durations.

Item Type:	Journal Article
Publication:	Physica B: Condensed Matter
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Ceramics;Microstructure;Dielectric;Ferroelectric.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	06 Aug 2008
Last Modified:	19 Sep 2010 04:48
URI:	http://eprints.iisc.ac.in/id/eprint/15463

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