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Nanocrystallization of $SrBi_2Nb_2O_9$ from glasses in the system $Li_2B_4O_7-SrO-Bi_2O_3-Nb_2O_5$

Prasad, Syam N and Varma, KBR (2002) Nanocrystallization of $SrBi_2Nb_2O_9$ from glasses in the system $Li_2B_4O_7-SrO-Bi_2O_3-Nb_2O_5$. In: Materials Science and Engineering B, 90 (3). pp. 246-253.

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Abstract

Transparent glasses in the system (100−x)$Li_2B_4O_{7–x}(SrO-Bi_2O_3-Nb_2O_5)$ (10≤x≤60) (in molar ratio) were fabricated by a conventional melt-quenching technique. Amorphous and glassy characteristics of the as-quenched samples were established via X-ray powder diffraction (XRD) and differential thermal analyses (DTA) respectively. Glass–ceramics embedded with strontium bismuth niobate, $SrBi_2Nb_2O_9$ (SBN) nanocrystals were produced by heat-treating the as-quenched glasses at temperatures higher than 500 °C. Perovskite SBN phase formation through an intermediate fluorite phase in the glass matrix was confirmed by XRD and transmission electron microscopy (TEM). Infrared and Raman spectroscopic studies corroborate the observation of fluorite phase formation. The dielectric constant $(\epsilon_r)$ and the loss factor (D) for the lithium borate, $Li_2B_4O_7$ (LBO) glass comprising randomly oriented SBN nanocrystals were determined and compared with those predicted based on the various dielectric mixture rule formalism. The dielectric constant was found to increase with increasing SBN content in LBO glass matrix.

Item Type: Journal Article
Additional Information: Copyright of this article belongs to Elsevier.
Keywords: Strontium bismuth niobate;Lithium borate;Glass–ceramic;Characterization
Department/Centre: Division of Chemical Sciences > Materials Research Centre
Date Deposited: 09 Jun 2006
Last Modified: 19 Sep 2010 04:29
URI: http://eprints.iisc.ernet.in/id/eprint/7564

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