scholarly journals The Influence of Vanadium Ions in Spectral Properties of ZnO–Sb2O3–B2O3 glasses

2020 ◽  
Vol 06 (09) ◽  
pp. 201-207
Author(s):  
N. Narasimha Rao, P. Raghava Rao, B. J.R.S.N. Swamy A. Chitti Babu, T.Sambasiva rao and N.Ch.Ramesh Babu
Keyword(s):  
Optical Absorption ◽  
Glass Network ◽  
Structural Disorder ◽  
Spectroscopic Studies ◽  
Esr Spectra ◽  
Ion Concentration ◽  
Absorption Bands ◽  
Valence States ◽  
Vanadium Ions

Spectroscopic investigations of V2O5 doped ZnO–Sb2O3–B2O3glass system was prepared by melt-quenching technique. ZnO–Sb2O3–B2O3 glasses containing varying concentrations of V2O5 ranging from 0.1 to 1.0 mol% were prepared, here spectroscopic studies such as Optical absorption, IR and ESR spectra have been carried out as a function of vanadium ion concentration. The optical absorption spectrum of glasses has exhibited two broad absorption bands corresponding to 2B2→2B1 and 2B2→2E transitions of VO2+ ions. The appearances of vibration bands in IR spectra are characteristic for B-O-B and V-O-V linkages, showing the network former role of V2O5. Vanadium ions are believed to be present in two possible valence states, namely V4+and V5+. Here with increasing presence of V2 O5 in the glass network, vanadium ions mostly exist in V4+state and occupy modifying positions. Such increase obviously suggests most structural disorder in the network as the concentration of V2 O5 is increased.

scholarly journals An Effectual Role of Molybdenum Ions on the Semiconducting Temperament of Na2O-PbO-Bi2O3-SiO2 Glasses

2021 ◽  
Author(s):  
Ch. Tirupataiah ◽  
M.V.Sambasiva Rao ◽  
L.Nageswara Rao ◽  
M.Naga Lakshmi
Keyword(s):  
Optical Absorption ◽  
Glass Network ◽  
Spectroscopic Studies ◽  
Spectroscopic Techniques ◽  
Bismuth Silicate ◽  
Absorption Studies ◽  
Proportionate Change ◽  
Doped Glasses ◽  
Quenching Method

Abstract Melt quenching method is adopted to synthesize multi-component glasses 10Na2O –30PbO –10Bi2O3 – (50-x)SiO2 – xMoO3 (where x = 0 to 5 mol%). These samples are characterized by XRD as well as analysed by optical absorption, EPR, and FTIR spectroscopic techniques in order to discuss the structure of the glass network. The proportionate change of Mo6+ ions into Mo5+ local states, which depolymerize the glass network, is publicized by optical absorption studies. EPR spectral analysis of the samples revealed C4v symmetry in a square pyramidal with a Mo=O bond. FTIR spectra of doped glasses report the presence of MoO4 and MoO6 structural units. All spectroscopic studies propped up the semi-conducting nature of sodium lead bismuth silicate glasses doped with the higher content of MoO3.

Role of structural disorder in optical absorption in silicon

2010 ◽  
Vol 82 (11) ◽  
Author(s):  
Robert J. Bondi ◽  
Sangheon Lee ◽  
Gyeong S. Hwang
Keyword(s):  
Optical Absorption ◽  
Structural Disorder

scholarly journals Physical, Optical, and Spectroscopic Studies on MgO-BaO-B2O3 Glasses

ISRN Ceramics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Samdani ◽  
Md. Shareefuddin ◽  
G. Ramadevudu ◽  
S. Laxmi Srinivasa Rao ◽  
M. Narasimha Chary
Keyword(s):  
Optical Absorption ◽  
Urbach Energy ◽  
Glass Composition ◽  
Glass Network ◽  
Spectroscopic Studies ◽  
Band Gaps ◽  
Compositional Dependence ◽  
Paramagnetic Resonance ◽  
Optical Band Gaps ◽  
Electron Paramagnetic

The mixed alkaline effect in double alkaline borate glasses MgO-BaO-B2O3 containing small proportions of copper oxide (CuO) has been studied. The glass samples are characterized by optical absorption, electron paramagnetic resonance (EPR), and Fourier transform infrared spectroscopy (FTIR). A red shift in optical absorption peaks with increasing MgO (decreasing BaO) concentration has been observed. The values of “g” tensor and hyperfine “A” tensor have shown inflections with glass composition. The number of spins (N) and paramagnetic susceptibility (χ) also exhibited mixed alkaline effect. The broadening of glass network with increase in MgO concentration is found from the FTIR spectra. Interestingly both density and molar volume have shown decreasing trend with glass composition. The optical band gaps exhibited a nonlinear compositional dependence. As expected, the glass samples possessed higher values of optical basicity (Λ), molar electronic polarizability (αm), and Urbach energy (ΔE).

scholarly journals Characterization and Optical Properties of MnO Doped CuO-Containing Phosphate Glass as Absorption Filters

2018 ◽  
Vol 15 ◽  
pp. 5983-5996
Author(s):  
Hytham Ahmed Abd El-Ghany
Keyword(s):  
Band Gap ◽  
Phosphate Glass ◽  
Optical Band Gap ◽  
Visible Region ◽  
Glass Network ◽  
Spectroscopic Studies ◽  
Progressive Increase ◽  
Cutoff Wavelength ◽  
Xrd Patterns

In order to demonstrate the intrinsic and extrinsic changes induced by MnO in the phosphate glass network, a glass system of composition 44P2O5-38ZnO-2CuO-(16-x)Na2O-xMnO (where, x = 1, 2, 3, 4, and 5 mol%) was prepared using the conventional melt quenching technique. XRD patterns confirmed the non-crystalline nature of the prepared samples. The density and molar volume as a function of MnO content were determined to characterize structure of the obtained glasses. The optical spectroscopic studies of the prepared samples were carried out over (190-1000 nm) spectral range. The prepared samples were found to behave as bandpass filters in the visible region of spectrum. The UV cutoff wavelength was shifted from 308 nm to 352 nm by increasing content of MnO which is very useful in the optical technology requirements such as ultraviolet preventing applications and the protection from UV-LASER. The optical band gap was decreased by increasing content of MnO whilst, the Urbach energy was increased. The decrease in optical band gap was attributed to the progressive increase in non-bridging oxygens (NBOs) concentration with the addition of MnO. The refractive index was found to be enhanced with the addition of MnO by the effect of increase in overall polarizability. However, the optical polarizability was found to be correlated to the chemical composition of the glass. The results reveal the role of MnO as a network modifier in the phosphate glass matrix.

Spectral Features of Lead Arsenate Glasses Doped with Copper Oxide

2013 ◽  
Vol 207 ◽  
pp. 55-67 ◽  
Author(s):  
T. Satyanarayana ◽  
G. Nagarjuna ◽  
K. Ravi Kiran
Keyword(s):  
Optical Absorption ◽  
Structural Disorder ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Copper Oxidation ◽  
Calorimetric Analysis ◽  
X Ray ◽  
Lead Arsenate ◽  
Valence States ◽  
Quenching Method

Lead arsenate glasses containing different concentrations of CuO ranging from 0 to 1.5 mol% (in steps of 0.3 mol%) were prepared by melt quenching method. Further, samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and differential scanning calorimetric analysis (DSC). A number of studies viz., optical absorption, luminescence and FTIR spectra also have been carried out on these glasses. XRD and SEM studies have confirmed that the prepared samples are of amorphous in nature. DSC results indicate the more structural degree of disorder for glass containing 1.5 mol% of CuO. From the IR spectra, it is observed that the intensity of bands due to ν1, ν2, ν3 and ν4 and vibrations of AsO3 group seems to be decreasing with shifting of the metacentres towards slightly higher wavenumber. The optical absorption and luminescence studies have indicated that copper exist in both the valence states viz., Cu+ and Cu2+. Finally the analyses of all results indicate that there will be growing degree of structural disorder with increase in the content of CuO. Keywords: Arsenate glasses, copper oxidation, optical absorption, luminescence

scholarly journals Effect of Stepwise Replacement of Non-Oxide to Oxide Group on Structural Properties of Bi2O3·LiF·B2O3 Glasses

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Susheel Arora ◽  
Virender Kundu ◽  
D. R. Goyal ◽  
A. S. Maan
Keyword(s):  
Ftir Spectroscopy ◽  
Molar Volume ◽  
Glass Network ◽  
Absorption Bands ◽  
Network Modifier ◽  
Xrd Pattern ◽  
Amorphous Nature ◽  
Oxide Group ◽  
Quench Method

Bismuth fluoroborate glasses with compositions xBi2O3·(40 − x)LiF·60 B2O3 (x = 0, 5, 10, 15, and 20) are synthesized by melt-quench method. XRD pattern is obtained for all the samples to confirm their amorphous nature. FTIR spectroscopy is carried out for the reported samples. It reflects the effect of replacement of a non-oxide group (LiF) with an oxide group (Bi2O3) in the glass network, due to the presence of the various absorption bands and their shifting with such replacement, assigning a role of network modifier to Bi2O3. Density and molar volume show an increase in their values with increase in Bi2O3 concentration. Theoretical optical basicity is calculated for the reported samples, which shows a decreasing trend with the increasing concentration of Bi2O3.

scholarly journals Optical Absorption of Chalcogenide Glass Ga2S3-La2S3 Doped with Erbium

2017 ◽  
Vol 18 (3) ◽  
pp. 342-346 ◽  
Author(s):  
V.V. Halyan ◽  
A.H. Kevshyn ◽  
І.А. Ivashchenko ◽  
І.D. Olekseuk ◽  
I.V. Danyliuk ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Chalcogenide Glass ◽  
Structural Disorder ◽  
Optical Absorption Spectra ◽  
Bandgap Width ◽  
Absorption Bands

The glasses of the La2S3–Er2S3–Ga2S3 system were synthesized from the melted samples which where quenched in to the cold 25-% solution of NaCl. Their optical absorption spectra were studied in the range of 1.2–2.9 eV at 80 K. For doped erbium glasses, there are narrow absorption bands with maxima at 2.53, 2.35, 2.27, 1.88, 1.54, 1.26 eV. With increasing of the content of La2S3 (30 - 40 mol. %) the bandgap width decreases (Eg = 2.83 - 2.73 eV) and the Urbach parameter increases (DE = 151 - 238 meV). These changes are determined by the structural disorder in the glasses.

Electrochemical behaviour and ESR spectra of nitro substituted mono- and dibenzoylmethylenebenzthiazolines and selenazolines

1979 ◽  
Vol 44 (5) ◽  
pp. 1540-1551 ◽  
Author(s):  
Jaro Komenda ◽  
Jiří Huzlík
Keyword(s):  
Electron Transfer ◽  
Esr Spectroscopy ◽  
Electrochemical Behaviour ◽  
Spectroscopic Studies ◽  
Esr Spectra ◽  
Slow Electron

Compounds of the type of 2-(4'-nitrobenzoyl)methylene-3-ethylbenzothiazoline (I) and 2-bis-(p-nitrobenzoyl)methylene-3-ethylbenzothiazoline (II) were studied polarographically and by ESR spectroscopy to obtain informations about their electrochemical and follow-up reactions and their conformation. Whereas with compounds of the type I the conjugation in their molecules is preserved, with type II the coplanarity of the molecules is disturbed, which is manifested in the values of the splitting constants of the ESR spectra and a slow electron transfer between both nitrophenyl substituents. These conclusions are supported by NMR spectroscopic studies.

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

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