FTIR and UV-Vis-NIR Spectral Studies of Borotellurite Glass

2015 ◽  
Vol 1107 ◽  
pp. 391-396
Author(s):  
A. Noranizah ◽  
K. Azman ◽  
H. Azhan ◽  
E.S. Nurbaisyatul ◽  
Mardhiah Abdullah

A glass system based on composition of 80TeO2-(10-x) B2O3 -10PbO-xNd2O3, where 0.0mol% ≤ x ≥ 2.5mol% was successfully prepared by melt-quenching method. The structural and optical behavior of the Nd3+ doped borotellurite glasses are well studied by mean of their FTIR, XRD as well as UV-Vis -NIR spectroscopy. The XRD pattern obtained confirms the amorphous nature of the glass. Meanwhile, the infra-red absorption spectra of glass samples obtained are recorded using an FTIR spectrometer in the wave number ranging from 400 to 4000 cm-1. The bands observed were attributed to the different modes of vibrations of Te-O band. From the absorption spectral measurements, the value of optical band gap (Eopt) and the Urbach energy (ΔE) values were calculated with the results were then been discussed nor reported. Quantitative justification of these absorption bands shows that the values of the experimental wave number for most absorption bands are in agreement with the theoretical ones. Optical absorption spectra show that the absorption edge has a tail extending towards lower energies. In general, an increment or a decrement in Urbach’s energy can be considered to be due to a deformation of glass network.

2017 ◽  
Vol 6 (1) ◽  
pp. 163-170 ◽  
Author(s):  
M. A. Algradee ◽  
A. Elwhab. B. Alwany ◽  
A. A. Higazy

The Yb3+-doped Lithium-Zinc-Phosphate glasses were prepared by means of conventional melt quenching method. The elastic moduli of the entire vitreous range of this doped glass system have been measured by the ultrasonic pulse-echo technique at 4 MHz. The ultrasonic wave velocities, the bulk, shear, longitudinal and Young's moduli are found to be rather sensitive to the Yb2O3 wt% content. The infrared absorption spectra were recorded in the frequencies range 4000 to 400 cm–1. Absorption bands and mode attributions have been fully discussed. Absorption midband positions and intensities are found to be strongly dependent on Yb2O3 wt%. The optical absorption spectra in the visible and ultraviolet region were recorded at room temperature. The obtained results showed that a gradual shift in the fundamental absorption edge toward longer wavelengths occurred and it is observed that the values ofEopt. are decreased and ΔE increased with the increase of Yb2O3 wt% content.


2016 ◽  
Vol 675-676 ◽  
pp. 405-408 ◽  
Author(s):  
Narong Sangwaranatee ◽  
Jakrapong Kaewkhao ◽  
Natthakridta Chanthima

In this research, the magnesium bismuth phosphate glasses doped with different concentration of Sm2O3 have been prepared using the melt quenching method at 1200 °C. Magnesium bismuth phosphate glasses are clear, homogenous and increased yellow color with increasing the concentration of Sm2O3. Physical and optical properties of glass samples were investigated. The results show that, the density and molar volumes were increased with increasing the concentration of Sm2O3. The absorption spectra in the wavelength range at 200 - 2500 nm was observed. It was found that the absorption bands have nine peaks with corresponding to 401, 439, 472, 945, 1081, 1231, 1378, 1480 and 1533 nm. Absorption bands at 401 and 1231 nm are highest absorption spectra in visible and near infrared region, respectively. For the luminescence spectrum of glass samples has shown four emission transitions at 562 (green), 598 (orange), 664 (red) and 705 nm with excitation wavelength at 401 nm. The wavelength at 401 and 598 nm has shown highest intensity of excitation and emission wavelength, respectively.


2014 ◽  
Vol 895 ◽  
pp. 236-240
Author(s):  
N.A. Azmi ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal

Understanding the optical properties of rare earth doped tellurite glasses with embedded metallic nanoparticles (NPs) are promising for photonics. Series of Nd3+ doped tellurite glasses containing Ag NPs having chemical composition (70-x)Te2O3-10MgO-20Li2CO3-0.5Nd2O3-xAg, where 0.0 x 1.0 mol% are synthesized. Their optical properties are measured using UV-Vis-NIR spectroscopy. The absorption spectra exhibits nine absorption bands in the wavelength range of 300-900 nm are obtained and the glass showed light emission due to 4F3/2 4I9/2 transition. The values of optical band gap Eopt and Urbach energy Eu are evaluated from the absorption band. The value of Eopt is found to lie between 2.78 and 2.91 eV for the direct transition whereas the Eu values lie between 0.27 and 0.37 eV. The optical behavior of the samples is studied with varying Ag NPs content and the results are compared with similar studies.


1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička

The mechanism of controlled anionic coordination dimerization of isoprene (i.e. 2-methyl-1,3-butadiene) in the system tetrahydrofuran-isoprene-alkali metal-dialkylamine was investigated by using absorption spectrophotometry in the range of visible radiation and gas chromatography. The effect of the alkali metal (Li, Na, K) and dialkylamine (dicyclohexylamine, N-isopropylcyclohexylamine, N-methylisopropylamine) on the absorption spectra was tested. By comparing chromatographic and spectrophotometric data, the absorption bands in the range of visible radiation were identified with the existence of π-complexes between oligomeric forms of isoprene and alkali metal dialkylamide.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.


2005 ◽  
Vol 19 (03) ◽  
pp. 119-128 ◽  
Author(s):  
M. PRASAD ◽  
M. CHANDRASEKHAR ◽  
V. CHANDRA MOULI

The electron spin resonance and optical absorption spectra of PbO-CdO glasses containing 1 mole% CuO have been investigated at room temperature. The optical absorption spectra of all glass samples have exhibited a broad asymmetric absorption band, which corresponds to a d–d transition of Cu 2+ ions. The prepared glass samples have been analyzed as a function of the photon energy. The results are interpreted based on the optical absorption spectral profiles and also the edge values upon the application of Davis and Mott's theory. From the ESR spectral features, the spin Hamiltonian parameters have been evaluated. The bonding coefficients were obtained, in order to elucidate the information on the Cu 2+ ligand bond nature.


1994 ◽  
Vol 49 (6) ◽  
pp. 849-851 ◽  
Author(s):  
G. C. Papavassiliou ◽  
I. B. Koutselas

The title compounds (natural low-dimensional semiconductors) show strong excitonic optical absorption bands in the UV-visible spectral region, because of the dielectric confinement of excitons. as in the cases of other similar systems based on PbX2-4, SnX2-4. PtI - X - PtIV-X , Cdx,Sy-clusters etc


2021 ◽  
Vol 10 (2) ◽  
pp. 58-62
Author(s):  
Yuni Susanti ◽  
Yeni Variyana

Initially, zeolite catalysts cannot be used for reactions involving hot liquid water, so it is necessary to modify the zeolite to be stable under these conditions. The synthesis of HY and hydrophobic zeolites aimed to determine the stability of zeolite in hot liquid water (HLW). The stability of zeolite in HLW is related to zeolite hydrophobicity. In this study, the main raw materials for the synthesis of HY zeolite were sodium aluminate (NaAlO2) and Ludox HS-40 by calcining the product at 350 oC for 1 hour. Furthermore, increasing the hydrophobicity of HY zeolite was carried out by modifying the external zeolite surface using organosilanes (aminopropyltriethoxysilane). The stability of two zeolites in HLW was set at 200 oC. Zeolite analysis used physical test and Fourier Transform-Infra Red (FTIR) Spectrometer. The results of the zeolite distribution in two phases confirmed that HY zeolite was completely dispersed in the water phase, while the zeolite one was dispersed in the organic phase. Moreover, the IR spectra of HY zeolite showed that the wide peak detection at wave number 720 cm-1 for beginning to disappear. This means that the HLW condition could be damaged to the d6r unit. Another result was shown by hydrophobic zeolite spectra with a stable peak for 72 hours. This indicates that the hydrophobic zeolite has thermal stability in HLW so that it can be used in chemical reaction catalytic applications that use on phase.


2017 ◽  
Vol 268 ◽  
pp. 62-66 ◽  
Author(s):  
S. Rashidah Misron ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal

Three lithium-sodium-phosphate glass samples with molar composition of (48.5–x)P2O5-20Na2O-30Li2O-0.5Sm2O3-1.0Er2O3-xAgNPs (where x = 0.01 g, 0.03 g and 0.05 g) are prepared using melt quenching method. The thermal stability and infrared absorption of synthesized samples are evaluated as a function of Ag NPs contents. Thermal and structural characterizations are made using differential thermal analysis (DTA) and Fourier transformed infrared (FTIR) spectroscopy, respectively. Thermal stability is found to vary in the range of 171 °C to 197 °C. FTIR spectra revealed various characteristic bonding vibrations related to the glass network structures. The IR absorption band around 570 cm-1 is assigned to the P-O-P bending vibrations while the occurrence of bands around 759 cm-1 and 913 cm-1 are allocated to the P-O-P symmetric stretching vibrations. The asymmetric stretching vibrations of (PO3)2- and (PO2)- units are observed around 1045 cm-1 and 1254 cm-1 , respectively. The appearance of a band around 1735 cm-1 is allocated to the free H2O molecules because of moisture attack to the sample. Influences of Ag NPs in the host matrix are analyzed and explained.


2016 ◽  
Vol 9 (2) ◽  
pp. 577-585 ◽  
Author(s):  
Matthias Buschmann ◽  
Nicholas M. Deutscher ◽  
Vanessa Sherlock ◽  
Mathias Palm ◽  
Thorsten Warneke ◽  
...  

Abstract. High-resolution solar absorption spectra, taken within the Network for the Detection of Atmospheric Composition Change Infrared Working Group (NDACC-IRWG) in the mid-infrared spectral region, are used to infer partial or total column abundances of many gases. In this paper we present the retrieval of a column-averaged mole fraction of carbon dioxide from NDACC-IRWG spectra taken with a Fourier transform infrared (FTIR) spectrometer at the site in Ny-Ålesund, Spitsbergen. The retrieved time series is compared to colocated standard TCCON (Total Carbon Column Observing Network) measurements of column-averaged dry-air mole fractions of CO2 (denoted by xCO2). Comparing the NDACC and TCCON retrievals, we find that the sensitivity of the NDACC retrieval is lower in the troposphere (by a factor of 2) and higher in the stratosphere, compared to TCCON. Thus, the NDACC retrieval is less sensitive to tropospheric changes (e.g., the seasonal cycle) in the column average.


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