IISc Logo    Title

etd AT Indian Institute of Science >
Division of Chemical Sciences >
Materials Research Centre (mrc) >

Please use this identifier to cite or link to this item: http://hdl.handle.net/2005/1062

Title: Transparent Glass Nono/Microcrystal Composites In MO-Bi2O3-B2O3(M= Sr, Ca) System And Their Physical Properties
Authors: Majhi, Koushik
Advisors: Varma, K B R
Keywords: Glass
Strantium Oxide Composites
Transparent Glass
Calcium Oxide Composites
Microcrystal Composites
Nanocrystal Composites
Glasses - Electro-Optic Properties
Glasses - Fabrication
Glass Nano/Microcrystal Composites
CaO-Bi2O3-B2O3 Glasses
SrO-Bi2O3-B2O3 Glasses
Submitted Date: Sep-2009
Series/Report no.: G23538
Abstract: Transparent glass-ceramics have been of industrial interest because of their multifarious applications. These are becoming increasingly important because of the flexibility that is associated with this route of fabricating intricate sizes and shapes as per the requirement. A number of glass-ceramics, based on well known ferroelectric crystalline phases (LiNbO3, LaBGeO5, SrBi2Nb2O9, Bi2WO6 etc.) were fabricated and their polar and electro-optic properties were reported. Keeping the potential applications of transparent glass-nano/microcrystal composites in view, attempts were made to fabricate SrBi2B2O7 and CaBi2B2O7 glasses and glass-nano/microcrystal composites. An attempt has been made to employ strontium bismuth borate SrBi2B2O7 (SBBO) as a reactive host glass matrix for growing the nanocrystals of ferroelectric oxides belonging to the Aurivillius family. The in situ nucleation and growth of SrBi2Nb2O9 (SBN) nanocrystals in a reactive SrBi2B2O7-Nb2O5 system and its influence on various physical (dielectric, pyroelectric and optical) properties were investigated. The strategy has been to visualize the formation of nanocrystalline SrBi2Nb2O9 as a result of the simple chemical reaction between glassy SrBi2B2O7 and Nb2O5. Indeed at lower concentrations of Nb2O5 transparent glasses were obtained which upon heat-treatment at appropriate temperatures yielded nanocrystalline SrBi2Nb2O9 phase in a transparent glass matrix. Textured SrBi2Nb2O9 ceramics were obtained by quenching the melts of SrBi2B2O7-Nb2O5 in equimolar ratio and their physical properties were studied. A strong anisotropy in physical properties (which are akin to single crystals) were demonstrated in the textured ceramics.
URI: http://etd.iisc.ernet.in/handle/2005/1062
Appears in Collections:Materials Research Centre (mrc)

Files in This Item:

File Description SizeFormat
G23538.pdf27.12 MBAdobe PDFView/Open

Items in etd@IISc are protected by copyright, with all rights reserved, unless otherwise indicated.


etd@IISc is a joint service of SERC & IISc Library ||
|| Powered by DSpace || Compliant to OAI-PMH V 2.0 and ETD-MS V 1.01