Structural and crystallization behavior of (Ba,Sr)TiO3 borosilicate glassesPLEASE SCROLL DOWN FOR ARTICLEborosilicate glasses (original) (raw)
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Open Journal of Inorganic Non-metallic Materials, 2012
A series of glasses were prepared by rapid melt quench method in the glass system (65 − x)[(Ba 0.6 Sr 0.4)TiO 3 ]-30[2SiO 2-B 2 O 3 ]-5[K 2 O]-x[La 2 O 3 ] (x = 0, 1, 2, 5 and 10). X-ray diffraction of glass samples were carried to check its amorphousity. Density of glass samples were measured using Archimedes principle. The refractive index of these glass samples lies between 2.39 to 2.80. Optical properties of these glass samples were studied using Infrared (IR) and Raman spectroscopic techniques. IR measurements were done over a continous spectral range 450-4000 cm-1 to study their stucture networking systematically while Raman spectra were recorded over a continous spectral range 200-2000 cm-1. IR spectra of all glass samples showed number of absorption peaks. These absorption peaks occurs due to asymetric vibrational streching of borate by relaxation of the bond B-O of trigonal BO 3. The Raman spectra of all glass samples exhibited different spectral bands and intensity of these bands changes drastically. The network structure of these glass samples is mainly based on BO 3 and BO 4 units placed in different structural groups.
A series of glasses were prepared by rapid melt quench method in the glass system (65 − x) [(Ba 0.6 Sr 0.4 )TiO 3 ]-30[2SiO 2 -B 2 O 3 ]-5[K 2 O]-x[La 2 O 3 ] (x = 0, 1, 2, 5 and 10). X-ray diffraction of glass samples were carried to check its amorphousity. Density of glass samples were measured using Archimedes principle. The refractive index of these glass samples lies between 2.39 to 2.80. Optical properties of these glass samples were studied using Infrared (IR) and Raman spectroscopic techniques. IR measurements were done over a continous spectral range 450 -4000 cm -1 to study their stucture networking systematically while Raman spectra were recorded over a continous spectral range 200 -2000 cm -1 . IR spectra of all glass samples showed number of absorption peaks. These absorption peaks occurs due to asymetric vibrational streching of borate by relaxation of the bond B-O of trigonal BO 3 . The Raman spectra of all glass samples exhibited different spectral bands and intensity of these bands changes drastically. The network structure of these glass samples is mainly based on BO 3 and BO 4 units placed in different structural groups.
A Review on Infrared Spectroscopy of Borate Glasses with Effects of Different Additives
Borate glasses are the technologically important class of glasses and play a significant role in various applications. Borate glasses contain planar BO 3 groups as structural units, rather than tetrahedral SiO 4 groups. The oxygen atoms are, as in SiO 2 , again connected to two network-forming atoms, in case of boron. The radial distribution analysis describes the B 2 O 3 glass structure as consisting of boroxol rings, that is, planar rings containing three boron atoms and three oxygen atoms. The network forming of the B 2 O 3 and the SiO 4 is affected with the addition of some metal cation additives Pb, Zn, Cd, and so forth. These additives also work as a network modifier and a nucleating agent for crystallization of glass. Therefore, the optical properties of the borate glasses have been changed significantly.
IR study of Pb–Sr titanate borosilicate glasses
The infrared spectra (IR) of various glass compositions in the glass system, [(Pb x Sr 1-x)O⋅TiO 2 ]-[2SiO 2 ⋅B 2 O 3 ]-[BaO⋅K 2 O]-[La 2 O 3 ], were recorded over a continuous spectral range (400-4000 cm-1) to study their structure systematically. IR spectrum of each glass composition shows a number of absorption bands. These bands are strongly influenced by the increasing substitution of SrO for PbO. Various bands shift with composition. Absorption peaks occur due to the vibrational mode of the borate network in these glasses. The vibrational modes of the borate network are seen to be mainly due to the asymmetric stretching relaxation of the B-O bond of trigonal BO 3 units. More splitting is observed in strontium-rich composition.
Borate glass structure by Raman and infrared spectroscopies
Journal of Molecular Structure, 1991
employed to probe the continuous evolution of borate glass structures as a function of the nature and concentration of alkali oxide modifier. At relatively low alkali contents, the glasses contain covalent networks consisting of interconnected units bearing BO, tetrahedra. Further addition of alkali oxide causes the progressive depolymerization of the network as a result of the formation of non-bridging oxygen atoms. Eventually, complete network disruption into small and highly charged borate units results in "ionic" glasses. The nature of the alkali cation determines the structure of these glasses by affecting several hightemperature isomerization or disproportionation equilibria. *Dedicated to the memory of Professor George Wilkinson. 0022-2860/91/$03,50 0 1991-Elsevier Science Publishers B.V.
Asian Journal of Convergence in Technology
Glass sample compositions of xCaO(1-x-z)-SiO 2 zB 2 O 3 with constant nominal CaO of x=33.33 mol% and varying concentrations of B 2 O 3 as z=50,60 and 66.67 mol% are prepared by conventional melt quench technique. Fourier transform infrared (FTIR) spectra of xCaO(1-x-z)-SiO 2 zB 2 O 3 glass system has been measured in the spectral range 400-4000 cm −1 low-frequency region 1700cm-1 to 400cm-1 and highfrequency region 4000cm-1 to 1700cm-1) at room temperature to understand the characteristic frequencies of the chemical bonds, bonding mechanisms and structure of electron shell of atoms, for the purpose to determine the molecular structure of the composition. It is found that the melting temperature of the glasses decreases with the increase of B 2 O 3 concentration and the melting temperature in the range of 950 o C-1100 o C for the samples which consist of 50, 60, and 66.67 mol% of B 2 O 3. In the low-frequency region (1700cm-1 to 400cm-1) the spectra of high B 2 O 3 containing glass showed an increased number of distinct peaks and several broad Gaussian in the thighfrequency region (1700cm-1 to 400cm-1). All the spectra are based on line corrected and deconvoluted to the appropriate number of Gaussians. Fourier transform infrared (FTIR) deconvoluted spectra were analyzed to determine the exact position and relative amounts of the IR bands responsible for the different silicate borates units. The distinct peaks and peak position of the deconvoluted Gaussians are assigned to Si-O-Si, B-O-B, Si-O-Ca, Si-O etc. bonds based on the previous scientific investigations. The presence of B 2 O 3 in the materials suggests that B 3+ occupies the network position and for the linkage Si-O-B in the glasses. The amorphous nature, the surface topography and composition of the prepared glasses was checked by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques respectively on optical inspection, did not show any evidence of phase separation, and all glasses are homogeneous.
Structural and optical properties of barium borosilicate glasses
Physica B: Condensed Matter, 2010
The 40SiO 2-30BaO-20B 2 O 3-10A 2 O 3 (A ¼ Y, La, Al, Cr) glasses were synthesized by melt quenching at 1550 1C. Controlled crystallization was carried out to convert these glasses to corresponding glass ceramics. The amorphous nature of as prepared glasses was ascertained from XRD diffraction pattern. Fourier-transform infrared spectroscopy was done to find out the basic structural units in these glasses. The effect of intermediate oxides on optical properties was investigated using UV-Visible spectra.