Dielectric and pyroelectric anisotropy in melt-quenched $BaBi_2(Nb-1 (-) V-x(x))O-9 ceramics

Karthik, C and Varma, KBR (2008) Dielectric and pyroelectric anisotropy in melt-quenched $BaBi_2(Nb-1 (-) V-x(x))O-9 ceramics. In: Materials Research Bulletin, 43 (11). pp. 3026-3036.

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Abstract

The (0 0 l) textured $BaBi_2(Nb-1 (-) V-x(x))(2)O-9 (where x = 0, 0.03,0.07, 0.1 and 0.13) ceramics were fabricated via the conventional melt-quenching technique followed by high temperature heat-treatment (800-1000 degrees C range). The influence of vanadium content and sintering temperature on the texture development and relative density were investigated. The samples corresponding to the composition x = 0.1 sintered at 1000 degrees C for 10 h exhibited the maximum orientation of about 67%. The Scanning electron microscopic studies revealed the presence of platy grains having the a-b planes perpendicular the pressing axis. The dielectric constant and the pyroelectric co-efficient values in the direction perpendicular to the pressing axis were higher. The anisotropy in the dielectric constant is about 100 (at 100 kHz) at the dielectric maximum temperature and anisotropy in the pyroelectric co-efficient is about 50 mu C cm(-2) degrees C-1 in the vicinity of pyroelectric anomaly for the sample corresponding to the composition x = 0.1 sintered at 1000 degrees C. Higher values of the dielectric loss and electrical conductivity were observed in the direction perpendicular to the pressing axis which is attributed to the high oxygen ion conduction in the a-b planes.

Item Type:	Journal Article
Publication:	Materials Research Bulletin
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Ceramics;Layered compounds;Dielectric properties.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	18 May 2009 06:46
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16757

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