# Structural and Dielectric Charactersics of Strontium Tetraborate-Bismuth Vanadate Glass-Ceramics

Varma, KBR and Shankar, MV and Subbanna, GN (1996) Structural and Dielectric Charactersics of Strontium Tetraborate-Bismuth Vanadate Glass-Ceramics. In: Materials Research Bulletin, 31 (5). pp. 475-482.

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## Abstract

Glasses of strontium tetraborate, containing up to 50 mole-percent bismuth vanadate [(1-x)SBO-xBiV (x = 0 to 0.50)], were prepared by splat quenching method. The glassy nature of these samples was confirmed by differential thermal analysis (DTA). The glass transition temperature $(T_g)$ and the crystallization temperature $(T_{cr})$ of the glasses decrease with increase in bismuth vanadate, $Bi_2VO_{5.5}$ (BiV) content. High resolution transmission electron microscopic studies reveal the presence of spherical particles of amorphous BiV (less than 10 nm in size) dispersed in the glassy matrix of strontium tetraborate, $SrB_40_7$ (SBO). The glasses of the compositions x = 0.25 to 0.50, on annealing at 500 $^oC (T_g)$ gave rise to crystalline BiV phase. Physical properties such as density, dielectric and optical transmission of these SBO:BiV glass-ceramics have been studied. The dielectric constant $(\in_r)$ of these glass-ceramics increases with increasing BiV content. The measured $\in_r$ values are found to be in good agreement with those predicted by the logarithmic mixture rule.

Item Type: Journal Article Materials Research Bulletin Elsevier Copyright of this article belongs to Elsevier. A. ceramics; A. glasses; C. electron microscopy; C. X-ray diffraction; D. dielectric properties Division of Chemical Sciences > Materials Research Centre 14 Mar 2007 19 Sep 2010 04:35 http://eprints.iisc.ac.in/id/eprint/9741