Effect of Stepwise Replacement of LiF by Bi2O3 and of Annealing on Optical Properties of LiF⋅B2O3 Glasses

Susheel Arora,Virender Kundu,A S Maan,D R Goyal

doi:10.5402/2012/193185

Susheel Arora, Virender Kundu + Show 2 more

Open Access

https://doi.org/10.5402/2012/193185

Copy DOI

Journal: ISRN Optics	Publication Date: Mar 7, 2012
Citations: 22	License type: CC BY 3.0

Affiliation: Maharshi Dayanand University, Kurukshetra University

Abstract

Bismuth fluoroborate glasses with compositions xBi2O3⋅(40-x)LiF⋅60 B2O3 (x=0,5,10,15, and 20) are synthesized by melt-quench method. Optical characterization was carried out to examine variation of optical band gap energy (Eg) and Urbach energy (EU) with respect to the concentration. It reflects the effect of stepwise replacement of non-oxide and less polarizable LiF by an oxide and more polarizable (Bi2O3) group on the optical properties of the samples. The value of Eg decreases with increase in concentration of Bi2O3. The samples were subjected to annealing at different temperatures (300°C, 350°C, and 400°C), and the effect of annealing on the optical properties of various samples was again studied. Annealing affects remarkably the values of Eg and EU in the samples with x=0.

Highlights

Fast cooling of the molten form of a substance makes it difficult to form a crystalline phase
The glass formation demands a random arrangement of various atomic and molecular species which form in borate glasses
The inclusion of LiF in the borate glass network brings out some structural changes [3], which in turn become responsible for the change in various properties

Summary

Introduction

Fast cooling of the molten form of a substance makes it difficult to form a crystalline phase. The sheet-like structure of boron-oxygen triangles in borate glasses, with their ability to connect themselves to form a network, has popularized B2O3 as one of the best glass former [1, 2]. Physical, electrical, and structural, and so forth are always sensitive to the variations in the microstructure of the substance. B2O3 glasses change their characteristics remarkably, when subjected to different annealing temperatures [18,19,20,21,22]. In these glasses, it is never discouraged to expect the formation of B3O6 rings called boroxol rings, by the combination of BO3 groups. Both of these factors result in a change in optical band gap energy

Experimental Details

Results and Discussion

Conclusions