Preparation and characterization of nanocrystalline powders of bismuth vanadate

Shantha, K and Varma, KBR (1999) Preparation and characterization of nanocrystalline powders of bismuth vanadate. In: Materials Science and Engineering B, 60 (1). 66-75 .

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Abstract

The influence of mechanical activation on the formation of Bi2VO5.5 bismuth vanadate (BiV) phase, was investigated by ball-milling a stoichiometric mixture of bismuth oxide and vanadium pentoxide. The structural evolution of the desired BN phase, via an intermediate BiVO4,phase, was investigated using X-ray powder diffraction; (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM). Milling for 54h. yielded monophasic gamma-BiV powders with an average crystallite size of 30 nm. The electron paramagnetic resonance (EPR) peaks associated with the V4+ ions are stronger and broader in nanocrystalline (n) BN than in the conventionally prepared microcrystalline (m) BN, suggesting theta significant portion of V5+ has been transformed to V4+ during milling. The optical bandgap of n-BiV was found to be higher than that of m-BiV. High density (97% of the theoretical density), fine-grained (average grain-size of 2 tun) ceramics with uniform grain-size distribution could be fabricated using n-BiV powders. These fine-grained ceramics exhibit improved dielectric, pyre and ferroelectric properties. (C) 1999 Elsevier Science S.A. All rights reserved.

Item Type:	Journal Article
Publication:	Materials Science and Engineering B
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Nanocrystalline powders;Bismuth vanadate;Preparation; Characterization
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	28 Jun 2011 09:25
Last Modified:	28 Jun 2011 09:25
URI:	http://eprints.iisc.ac.in/id/eprint/38732

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