Mechanical and Optical Properties for Li2O–ZnO–P2O5:xYb2O3 Glasses

2017 ◽  
Vol 6 (1) ◽  
pp. 163-170 ◽  
Author(s):  
M. A. Algradee ◽  
A. Elwhab. B. Alwany ◽  
A. A. Higazy
Keyword(s):  
Absorption Spectra ◽  
Fundamental Absorption Edge ◽  
Ultrasonic Pulse ◽  
Phosphate Glasses ◽  
Ultraviolet Region ◽  
Absorption Bands ◽  
Young’S Moduli ◽  
Quenching Method ◽  
Doped Glass ◽  
Pulse Echo

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.

Spectral Investigations of Dy3+-Doped Gd2O3-CaO-P2O5 Glasses

2016 ◽  
Vol 675-676 ◽  
pp. 384-388 ◽  
Author(s):  
Piyachat Meejitpaisan ◽  
Chittra Kedkaew ◽  
C.K. Jayasankar ◽  
Jakrapong Kaewkhao
Keyword(s):  
Absorption Spectra ◽  
Emission Spectra ◽  
Ground Level ◽  
Phosphate Glasses ◽  
Absorption Bands ◽  
Quenching Effect ◽  
Ion Concentrations ◽  
Increase With Increase ◽  
Doped Glasses ◽  
Doped Glass

Dy3+-doped phosphate glasses of the compositions 20Gd2O3 : 10CaO : (70-x)P2O5 : xDy2O3, where x = 0.05, 0.10, 0.50, 1.00 and 1.50 mol% have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. All the transitions in the absorption spectra are originated from the 6H15/2 ground level to the various excited states and these are intra configuration (f-f) transitions. The observed twelve absorption bands centered at 349, 362, 387, 425, 451, 473, 750, 800, 895, 1089, 1266 and 1676 nm are assigned to 6P7/2, 4P3/2, 4F7/2, 4G11/2, 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6H9/2 and 6H11/2 transitions, respectively. The absorption spectra of glasses increase with increase in Dy3+ ion concentrations. The emission spectra of Dy3+-doped glasses are observed to be centered at 483, 573, 662 and 752 nm originated from the 4F9/2→6H15/2, 4F9/2→6H13/2, 4F9/2→6H11/2 and 4F9/2→6H9/2 transitions, respectively under excitation at 349 nm. The highest emission intensity of Dy3+-doped glass is 0.50 mol% due to concentration quenching effect. The experimental lifetimes are found to decrease when Dy3+ ion concentrations increased due to energy transfer process between Dy3+ ions.

Visible Luminescence Properties of Sm3+ Doped Magnesium Bismuth Phosphate Glasses

2016 ◽  
Vol 675-676 ◽  
pp. 405-408 ◽  
Author(s):  
Narong Sangwaranatee ◽  
Jakrapong Kaewkhao ◽  
Natthakridta Chanthima
Keyword(s):  
Absorption Spectra ◽  
Near Infrared ◽  
Infrared Region ◽  
Phosphate Glasses ◽  
Excitation Wavelength ◽  
Absorption Bands ◽  
Visible Luminescence ◽  
Yellow Color ◽  
Bismuth Phosphate ◽  
Quenching Method

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.

scholarly journals Photographic investigation of the absorption spectra of chlorophyll and its derivatives in the violet and ultraviolet region of the spectrum

1898 ◽  
Vol 63 (389-400) ◽  
pp. 389-396 ◽  
Keyword(s):  
Absorption Band ◽  
Absorption Spectra ◽  
Solar Spectrum ◽  
Ultraviolet Region ◽  
Absorption Bands

This is well known from the investigations of Soret, Gamgee, and others, hæmoglobin and its coloured derivatives show a characterics absorption band lying between the lines and M of the solar spectrum. The band has been shown to vary in position between narrow limits; in some derivatives it is nearer the red, and in others nearer the violet, end of the spectrum, and is of all the blood absorption bands the most stable.

Optical Analysis of RE3+: Boro-Fluoro-Phosphate Glasses

2010 ◽  
Vol 161 ◽  
pp. 13-41
Author(s):  
B. Sudhakar Reddy ◽  
S. Buddhudu
Keyword(s):  
Absorption Spectra ◽  
Emission Spectra ◽  
Green Emission ◽  
Phosphate Glasses ◽  
Radiative Properties ◽  
Composition Series ◽  
Absorption Bands ◽  
Intensity Parameters ◽  
Doped Glasses ◽  
Nir Emission

We report here on the preparation and optical characterization of certain rare earth (Nd3+,Tb3+,Pr3+ &Tm3+ each in 0.2 mol %) ions doped in two new series glasses in the following composition: Series A: 69.8 B2O3 – 10 P2O5 – 10(ZnO/CdO/TeO2) – 10 AlF3 Series B: 69.8 B2O3 – 10 P2O5 – 10(ZnO/CdO/TeO2) – 10 LiF By applying the Judd-Ofelt intensity parameters of Nd3+: BFP glasses, radiative properties of the emission transitions ( 4F3/2 ®4IJ=9/2, 11/2 &13/2 ) at 906, 1079 and 1349nm have been evaluated. By applying the Judd-Ofelt intensity parameters, radiative properties for Er3+ ions doped glasses, the NIR emission (4I13/2 4I15/2 ) at 1547nm , and also visible green emission (4S3/2 4I15/2 ) at 547nm have been evaluated. Measured absorption spectra of Pr3+: BFP glasses have shown eight absorption bands at 443, 469, 481, 589 , 1008, 1419, 1523 and 1930 nm which correspond to the transitions 3H4 ®3P2, 3P1, 3P0, 1D2, 1G4,3F4, 3F3 and 3F2 respectively. Absorption spectra of Tm3+: glasses have revealed five absorption bands at 466, 685, 790, 1206 and 1644 nm which corresponding to the transitions 3H6®1G4, 3F3, 3H4, 3H5 and 3F4 respectively. Pr3+: glasses, with an excitation at 442nm (3H4 ®3P2), a orange-red emission at 600 nm (1D2® 3H4) has been observed. In the case of Tm3+: glasses, upon excitation with 355nm (3H6®1D2), blue emissions at 452 nm (1D2®3F4) and at 476 nm (1G4®3H6) are observed. From the measured NIR emission spectra of Pr3+: BFP glasses, an NIR emission at 1354nm (1G4®3H5) and form Tm3+: glasses, an NIR emission (3F4®3H6) at 1809 nm are observed with an Ar+ laser (514.5 nm) as the excitation source.

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
Keyword(s):  
Absorption Spectra ◽  
Glass Network ◽  
Nir Spectroscopy ◽  
Wave Number ◽  
Spectral Studies ◽  
Absorption Bands ◽  
Urbach’S Energy ◽  
Ftir Spectrometer ◽  
Quenching Method ◽  
Optical Behavior

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.

Elastic properties of lead-phosphate glasses doped with erbium trioxide

2008 ◽  
Vol 86 (11) ◽  
pp. 1349-1352 ◽  
Author(s):  
B Eraiah ◽  
D Geetha ◽  
R V Anavekar
Keyword(s):  
Elastic Properties ◽  
Ultrasonic Pulse ◽  
Phosphate Glasses ◽  
Lead Phosphate ◽  
Increase With Increase ◽  
Debye Temperatures ◽  
Structure Of Glasses ◽  
Increasing Trend ◽  
Pulse Echo ◽  
62.20 Dc

The elastic properties of xEr2O3·(50 – x) PbO·50P2O5 (x = 0.1 to 0.5 mol%) glasses are investigated using ultrasonic pulse-echo measurements and their elastic properties are characterized at room temperature. Results from the studies show that both longitudinal and transverse velocities increase with increase of Er2O3 concentration. The elastic constants C11, C12, C44, and Young’s modulus show increasing trend while Bulk modulus and Poisson’s ratio show an increasing trend up to 0.4 mol% and 0.3 mol% of Er2O3, respectively, then there is sudden decreasing trend observed. But in the case of Debye temperatures the reverse trend has been observed. Another notable observation is that the glass with 0.4 mol% and 0.5 mol% of Er2O3 concentration exhibits high velocities and high elastic moduli. This behavior of the elastic properties is related to the change in the structure of glasses as well as the interatomic bonding.PACS No.: 62.20.DC

Оценка реальной чувствительности приемочного ультразвукового контроля рельсов

2020 ◽  
pp. 17-27
Author(s):  
А.А. Шелухин
Keyword(s):  
Ultrasonic Pulse ◽  
Piezoelectric Transducers ◽  
Acoustic Path ◽  
Metallic Inclusion ◽  
Inclusion Type ◽  
The Real ◽  
Rail Head ◽  
Pulse Echo

In this article, the analysis of the acoustic path during the ultrasonic pulse echo testing of the rail head in production is carried out. The influence of the parameters of the applied piezoelectric transducers on the distribution of sensitivity for the sounding scheme used in the existing installations is estimated and the real sensitivity of detecting defects of the «non-metallic inclusion» type is estimated.

Mechanism of anionic coordination dimerization of isoprene

1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička
Keyword(s):  
Gas Chromatography ◽  
Alkali Metal ◽  
Absorption Spectra ◽  
Visible Radiation ◽  
Absorption Bands ◽  
Absorption Spectrophotometry ◽  
Spectrophotometric Data ◽  
Oligomeric Forms

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.

scholarly journals X-ray Diffraction Analysis and Williamson-Hall Method in USDM Model for Estimating More Accurate Values of Stress-Strain of Unit Cell and Super Cells (2 × 2 × 2) of Hydroxyapatite, Confirmed by Ultrasonic Pulse-Echo Test

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2949
Author(s):  
Marzieh Rabiei ◽  
Arvydas Palevicius ◽  
Amir Dashti ◽  
Sohrab Nasiri ◽  
Ahmad Monshi ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Ultrasonic Pulse ◽  
High Accuracy ◽  
Unit Cell ◽  
Deformation Model ◽  
X Ray Diffraction ◽  
Uniform Deformation ◽  
X Ray ◽  
Pulse Echo

Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffraction; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is performed for the validation of the novelty assumptions.

scholarly journals Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Spectroscopic Properties ◽  
Absorption Bands ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Hartree Fock ◽  
Tauc Plot ◽  
Electrochemical Approach

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.

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