scholarly journals Optical Properties of LiF–Li2O –WO3–B2O3  Glasses

2020 ◽  
pp. 344-348
Author(s):  
M. Srinivasa Reddy ◽  
S. Shankaraiah
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Reflection Spectra ◽  
Composition Parameter ◽  
Melt Quenching ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Optical Absorption And Reflection

<p>Glass with compositions  xLiF–(30−x)Li<sub>2</sub>O –10WO<sub>3</sub>–60B<sub>2</sub>O<sub>3</sub>  for 5 ≤ x ≤ 25 mol% have been prepared using the normal melt quenching technique. The optical absorption and reflection spectra were recorded at room temperature in the wavelength range 300-800 nm. From the absorption edge studies, the values of the optical band gap (E<sub>opt</sub>) and Urbach energy (ΔE) have been evaluated. The values of E<sub>opt</sub> and ΔE vary non-linearly with composition parameter, showing the mixed alkali effect.</p>

Optical Properties of Silica Borotellurite Glass Doped with Manganese Oxide

2017 ◽  
Vol 268 ◽  
pp. 18-22 ◽  
Author(s):  
I. Zaitizila ◽  
Mohamed Kamari Halimah ◽  
Farah Diana Mohammad ◽  
Mohd Shah Nurisya
Keyword(s):  
Optical Properties ◽  
Manganese Oxide ◽  
Band Gap ◽  
Diffraction Pattern ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Molar Fraction ◽  
Chemical Formula ◽  
Melt Quenching ◽  
Amorphous Nature

Silica borotellurite glasses doped with manganese oxide with chemical formula {[(TeO2)0.7(B2O3)0.3­]0.8[SiO2]0.2}1-x{MnO2}x (where x = 0.0, 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction) were fabricated. Silica were extracted from the burning process of rice husk. Glass samples were prepared by using the melt-quenching technique. The FTIR spectra showed that the addition of MnO₂ contributed to the transformation of TeO4 to TeO3. The diffraction pattern of XRD showed a broad hump which indicates the amorphous nature of the samples. The result for both optical band gap and Urbach energy showed decreasing trend as the concentration of manganese increased.

Optical Properties of [(TeO2)0.7 (B2O3)0.3]1-x (Bi2O3)x Glass System

2015 ◽  
Vol 1107 ◽  
pp. 426-431 ◽  
Author(s):  
Azuraida Amat ◽  
Mohamed Kamari Halimah ◽  
Nurazlin Ahmad
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Glass Composition ◽  
Melt Quenching ◽  
Quenching Temperature ◽  
Glass Forming ◽  
Refractive Index Increase ◽  
Quenching Method

Ternary tellurite based glasses [(TeO2)0.7 (B2O3)0.3]1-x (Bi2O3)x was prepared by melt quenching method with suitable melting and quenching temperature. A series of glasses were selected from 0.05 to 0.30 mol % and its glass-forming region was determined. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO). The values of optical band gap, Eopt decreases when Bi2O3 content increases. Urbach energy for each composition was also calculated and was found to be dependent on the glass composition.

scholarly journals Optical Properties of Erbium doped Molybdenum Tellurite Glasses

2016 ◽  
Vol 15 (1) ◽  
pp. 17-27
Author(s):  
B Eraiah
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Urbach Energy ◽  
Amorphous Semiconductors ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Erbium Doped ◽  
Uv Visible ◽  
Quenching Method ◽  
Indirect Band Gap

The glasses with the composition of xEr 2 O 3 -5AgCl- 15MoO 3 -(80-x) TeO 2 (x = 0, 0.5 and 1 mol%, named as SMT0, SMT1 and SMT2, respectively) were synthesized using conventional melt quenching method and their optical properties were investigated through UV-Visible spectrophotometer. Density and molar volume values of the glass samples were estimated, their values were found in the range from 5.52 to 5.64 g/cm 3 and 27.737 to 28.689 cm 3 , respectively. The UV absorption spectra were recorded at room temperature in the wavelength range 200-1100nm. From the absorption edge data, it is found that both the direct and indirect type transitions may takeplace. The direct and indirect band gap values are ranging from 1.92 to 2.29 eV and 1.24 to 1.77 eV, respectively. Also, the Urbach energy (E tail ) values were determined and their values are ranging from 0.33 to 0.54 eV. These obtained E tail values are well matched with amorphous semiconductors (0.046 to 0.66 eV).

Optical Properties of Nd Doped Lead Borotellurite Glass

2016 ◽  
Vol 846 ◽  
pp. 193-198 ◽  
Author(s):  
Azman Kasim ◽  
H. Azhan ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
M.R.S. Nasuha
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Rare Earth Ions ◽  
Band Gaps ◽  
Refractive Indices ◽  
Excitation Wavelength ◽  
Gap Energy ◽  
Trivalent Rare Earth

Many trivalent rare earth ions such as Er3+, Tm3+, Ho3+, Pr3+ and Nd3+ were doped as absorption and emission centers in glass hosts. In this work, lead borotellurite (PBT) glass doped with neodymium ion (Nd3+) has been prepared and characterized by mean of their optical properties. The UV-Vis measurement has been carried out in order to determine the optical band gap energy, reflective indices and the polarizability. Optical absorption spectra of the glass samples are recorded in the range 400–900 nm at room temperature From the result, there are six significant absorption peaks that corresponds to 525 nm, 584 nm, 683 nm, 747 nm, 805 nm and 878 nm wavelength have been observed with the most predominant peak to be used as excitation wavelength is found centered at 584 nm. The energy band gaps as well as the refractive indices were found to vary from 2.50eV to 2.59eV and from 1.89 to 1.96 with mol% of Nd content respectively. Meanwhile, the polarizability shows a similar trend of results to refractive indices as it varies from 5.56 x 10-24 cm3 to 5.63 x 10-24 cm3. These results will be discussed further in details.

Optical Properties of K2O-Li2O-WO3-B2O3 Glasses: Evidence of Mixed Alkali Effect

2016 ◽  
Vol 46 (2) ◽  
pp. 808-816 ◽  
Author(s):  
Avula Edukondalu ◽  
T. Sripathi ◽  
Shaik Kareem Ahmmad ◽  
Syed Rahman ◽  
K. Sivakumar
Keyword(s):  
Optical Properties ◽  
Mixed Alkali ◽  
Mixed Alkali Effect

Investigation of Optical Properties of ZnO/MnO2, ZnO/TiO2 and ZnO/MnO2/TiO2 Nanocomposites

2014 ◽  
Vol 938 ◽  
pp. 123-127 ◽  
Author(s):  
G. Shanmuganathan ◽  
I.B. Shameem Banu
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Energy Gap ◽  
Visible Region ◽  
Solid State Reaction Method ◽  
Morphological Properties ◽  
Energy Dispersive Analysis ◽  
Reaction Method ◽  
Uv Visible

ZnO nanocomposites such as (ZnO)0.8(MnO2)0.2, (ZnO)0.8(TiO2)0.2and (ZnO)0.8(MnO2)0.1(TiO2)0.1were prepared by solid state reaction method at room temperature. The structural analysis was carried out with help of powder XRD to confirm the formation of the composites. The morphological properties and presence of elemental compositions were analyzed with scanning electron microscope and energy dispersive analysis spectroscopy respectively. Optical properties were studied with UV visible spectrophotometer. From the transmittance spectrum, it is concluded that the synthesized composite materials have the transmittance in the range of 80 to 95% in the visible region. The calculated optical band gap values for pure ZnO is 3.16 eV and the values are 3.7eV, 5.27eV and 4.46eV for the composites ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2, respectively. The study has found that the ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2composites have very large energy gap as that of insulator.

Effect of Samarium Ions on Physical and Optical Properties of Zinc Borotellurite Glass System

2021 ◽  
Vol 317 ◽  
pp. 100-108
Author(s):  
Siti Nasuha Mohd Rafien ◽  
Azman Kasim ◽  
Norihan Yahya ◽  
Azhan Hashim ◽  
Wan Aizuddin Wan Razali
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Molar Volume ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Glass System ◽  
X Ray Diffraction ◽  
Indirect Transition ◽  
Vis Spectroscopy ◽  
Amorphous Nature

Modifying the physical and optical properties of zinc borotellurite glasses by controlling rare earth (RE) doping is important in order to obtain high quality glass. In this study, Samarium (Sm3+) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique with chemical composition (where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%). The physical properties by mean of their density as well as molar volume were measured while the optical properties have been studied through UV-Vis spectroscopy in order to determine the optical band gap (Eopt) and Urbach energy (ΔΕ) of the glass system. Optical absorption spectra of the glass samples were recorded in the range 350 nm - 750 nm at room temperature. The amorphous nature of the glass was confirmed from X-ray diffraction techniques. The density and molar volume of the glass samples were found to vary with respect to Sm3+ ions content. The value of optical band gap, Eopt lies between 2.605 eV to 2.982 eV for the direct transition and 2.768 eV to 3.198 eV for the indirect transition respectively. Meanwhile, the Urbach energy, ΔE was observed in the range of 0.112 eV to 0.694 eV respectively. The physical and optical properties were found to be strongly affected by the varying concentration of Sm3+ ions. Some other results will be analysed and discussed in detail.

Growth of Au Nanoparticles Stimulate Spectroscopic Properties of Er3+ Doped TeO2-ZnO-Na2O Glasses

2014 ◽  
Vol 895 ◽  
pp. 254-259 ◽  
Author(s):  
Asmahani Awang ◽  
Sib Krishna Ghoshal ◽  
M.R. Sahar ◽  
M. Reza Dousti ◽  
Fakhra Nawaz
Keyword(s):  
Heat Treatment ◽  
Optical Absorption ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Spectroscopic Properties ◽  
Au Nps ◽  
Amorphous Nature ◽  
Gold Nps

The changes in optical properties of 70TeO2-20ZnO-10Na2O-0.5Er2O3-0.2Au glass system are stimulated by varying the heat treatment duration. The XRD data reveals broad humps in range of 25-35 degree representing the amorphous nature of the glass materials. The optical absorption edge at room temperature is used to estimate the direct (Edir), indirect (Eindir) optical band gap and the Urbach energy (EU). The value of Edirlies between 2.937 to 2.943 eV, while the value of Eindirlies within 2.478 to 2.502 eV. The value of EUis found to increase with longer time of heat treatment and lies between 0.409 to 0.424 eV. The characteristic surface plasmon resonance (SPR) band of Au nanoparticles (NPs) was observed at ~630 nm of optical absorption spectra. The strong and medium green upconversion (UC) fluorescence from Er3+centred at 547 and 533 nm were observed at room temperature, in addition to a weak red UC fluorescence from Er3+centred at 637 nm. The SPR stimulated by the presence of Au NPs enhanced the luminescence intensity by four and five folds for 1 and 4 hours heat treatment, respectively. The results indicate that there is a large influence of growth of gold NPs on the optical and spectroscopic properties of glass samples. Our results may be useful for the fabrication of nanophotonic materials.

MIXED ALKALI EFFECT IN BORATE GLASSES — EPR AND OPTICAL BAND GAP STUDIES IN xNa2O-(30-x)K2O-70 B2O3 GLASSES DOPED WITH Gd3+ IONS

2004 ◽  
Vol 18 (02n03) ◽  
pp. 83-97 ◽  
Author(s):  
R. P. SREEKANTH CHAKRADHAR ◽  
K. P. RAMESH ◽  
J. L. RAO ◽  
J. RAMAKRISHNA
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Physical Parameters ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Cubic Symmetry ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Boron Ions ◽  
Electron Paramagnetic

Mixed alkali borate x Na 2 O -(30-x) K 2 O -70 B 2 O 3(5≤x≤25) glasses doped with 0.5 mol% of gadolinium ions have been investigated by using electron paramagnetic resonance (EPR) and optical absorption techniques, as a function of alkali content, to look for the "mixed alkali effect" on the spectral properties of the glasses. The EPR spectrum consists of three prominent features with effective g-values, g≈5.6, 2.8 and 2.0, and two weak features at g≈3.3 and 4.3. The three EPR signals at g≈2.0, g≈2.8 and g≈5.6 are attributed to Gd 3+ ions located at sites with weak, intermediate and strong cubic symmetry fields, respectively. In principle these sites may be of network forming and network modifying types. Ionic radius considerations suggest that gadolinium ions cannot substitute the much smaller boron ions and thus only the network modifier site is acceptable. The number of spins (N) participating in resonance and its paramagnetic susceptibility (χ) for g≈5.6 resonance line have been calculated. It is interesting to note that N and χ increase with x and reach a maximum around x=15 and thereafter decrease showing the mixed alkali effect in these glasses. From ultraviolet absorption edges, the optical band gap energies were evaluated. It is interesting to note that the optical band gap energies for these glasses decrease slightly with increasing x and reach a minimum around x=10, and thereafter increase showing the mixed alkali effect. Optical band gap energies (E opt ) obtained in the present work vary from 2.20–3.35 eV for both the direct and indirect transitions. The physical parameters of the glasses have been evaluated with respect to the composition.

scholarly journals Effect of Vanadium on Structural and Optical Properties of Borate Glasses Containing Er3+ and Silver Nanoparticles

2021 ◽  
Author(s):  
Nur Adyani Zaini ◽  
Syafawati Nadiah Mohamed ◽  
Zakiah Mohamed
Keyword(s):  
Optical Properties ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Structural And Optical Properties ◽  
Intensity Parameter ◽  
Vanadium Concentration ◽  
Prepared Glass ◽  
Amorphous Nature ◽  
Quenching Method ◽  
Xrd Patterns

Glass samples (59.5 &ndash; x) B2O3 &ndash; 20Na2O &ndash; 20CaO &ndash; xV2O5 &ndash; Er2O3 &ndash; 0.5AgCl (x = 0 &ndash; 2.5 mol%) were prepared using melt &ndash; quenching method to investigate the structural and optical properties of the glass. The structural of the glass were characterized by using XRD, TEM and FTIR, meanwhile the optical properties were characterized by UV &ndash; VIS absorption. The XRD patterns confirmed the amorphous nature of the prepared glass samples. FTIR confirmed the presence of VO4, VO5, BO3, and BO4 vibration, and this result showed NBO increased with increasing vanadium concentration. The UV &ndash; Vis &ndash; NIR spectra exhibits six absorption band centered at 490, 520, 540, 660, 800, and 980 nm. The optical band gap (Eopt), Urbach energy and refractive index shown decrease, increase and increase, respectively. The Judd &ndash; Ofelt intensity parameter reveal the trends was Ω2 &amp;gt; Ω4 &amp;gt; Ω6. There are three emission bands at 516 nm, 580 nm, and 673 nm which are represented by 2H11/2 &ndash; 4I15/2, 4S3/2 &ndash; 4I15/2, and 4F15/2 &ndash; 4I15/2, respectively under 800 nm excitation was obtained.

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