Dielectric, piezoelectric, and pyroelectric anisotropy in KCL- modified grain-oriented bismuth vanadate ceramics

Shantha, K and Varma, KBR (1999) Dielectric, piezoelectric, and pyroelectric anisotropy in KCL- modified grain-oriented bismuth vanadate ceramics. In: Journal of Materials Research, 14 (2). pp. 476-486.

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Abstract

The effect of the additive KCl, on the structural, microstructural, and polar properties of bismuth vanadate (BiV) ceramics is investigated. The scanning electron microscopic (SEM) studies reveal a remarkable modification in the microstructure and the occurrence of high grain-orientation (75%) on KCl addition. The energy dispersive x ray (EDX) analyses indicate the presence of chemically inhomogeneous distribution of KCl, with core-shell-like grain structure. The KCl-modified BiV samples exhibit a broad and depressed phase transition, with no frequency dispersion, as a result of the increased internal stress and the formation of core-shell-like grain structure. Significant anisotropies are observed in the dielectric, piezoelectric, and pyroelectric responses of these grain-oriented ceramic samples. These samples are characterized by near rectangular ferroelectric hysteresis loops, with a significant anisotropy in the Pr (Pr\bot /Pr\| =2.43, at 300 K) and Ec (Ec\| /Ec\bot =2.22, at 300 K) values between the directions parallel and perpendicular to the cold-pressing axis.

Item Type:	Journal Article
Publication:	Journal of Materials Research
Publisher:	Materials Research Society
Additional Information:	Copyright of this belongs to Materials Research Society.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	28 Dec 2004
Last Modified:	19 Sep 2010 04:15
URI:	http://eprints.iisc.ac.in/id/eprint/1650

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