Effect of Bi2O3 Content on the Properties of Bi2O3-BaO-B2O3 Glass System

2008 ◽  
Vol 55-57 ◽  
pp. 869-872 ◽  
Author(s):  
Jakrapong Kaewkhao ◽  
Artorn Pokaipisit ◽  
Weerapong Chewpraditkul
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Molar Volume ◽  
Absorption Spectra ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Optical Absorption Spectra ◽  
Network Modifier ◽  
Oxide Ion

Glasses with composition xBi2O3:(60-x)BaO:40B2O3 with 10£x£50 (in mol%) have been prepared using the normal melt-quench technique. The optical absorption spectra of the glasses have been recorded in the wavelength range 400-700 nm. The fundamental absorption edge has been identified from the optical absorption spectra. The values of optical band gap are decreased with the addition of Bi2O3. The density and molar volume studies indicated that Bi2O3 in these glasses is acting partly as network modifier and partly as network former.Values of the theoretical optical basicity are also reported and discuss in term of oxide ion polarizability.

Optical Investigation of Bi2O3-B2O3 Glass System

2010 ◽  
Vol 93-94 ◽  
pp. 336-339 ◽  
Author(s):  
Kitipun Boonin ◽  
Jakrapong Kaewkhao ◽  
Pichet Limsuwan
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Absorption Spectra ◽  
Wavelength Range ◽  
Absorption Edge ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Optical Investigation ◽  
Optical Absorption Spectra ◽  
Molar Volumes

Glasses with composition xBi2O3:(100-x)B2O3 with 30x70 (in mol%) have been prepared using the normal melt-quench technique and investigated their properties. The optical absorption spectra of the glasses have been measured in the wavelength range 400-700 nm. It has been found that, the fundamental absorption edge has been identified from the optical absorption spectra. The values of optical band gap were decreased and the molar volumes were increased, with the addition of Bi2O3, due to the formulation of non-bridging oxygen (NBOs).

Band-gap engineering in amorphous/microcrystalline ScxGa1-xN.

2001 ◽  
Vol 693 ◽  
Author(s):  
M. E. Little ◽  
M. E. Kordesch
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Absorption Spectra ◽  
Optical Band Gap ◽  
Optical Absorption Spectra ◽  
X Ray Diffraction ◽  
Band Gap Engineering ◽  
X Ray ◽  
Bilayer Films ◽  
Quartz Substrates

AbstractReactive sputtering was used to grow thin films of ScxGa1-xN with scandium concentrations of 20%-70% on quartz substrates at temperatures of 300-675 K. X-ray diffraction (XRD) of the films showed either weak or no structure, suggesting the films are amorphous or microcrystalline. Optical absorption spectra were taken of each sample and the optical band gap was determined. The band gap varied linearly with increasing Ga concentration between 2.0 and 3.5 eV. Ellipsometry was used to confirm the band gap measurements and provide optical constants in the range 250-1200 nm. ScN and GaN have different crystal structures (rocksalt and wurzite, respectively), and thus may form a heterogeneous mixture as opposed to an alloy. Since the XRD data were inconclusive, bilayers of ScN/GaN were grown and optical absorption spectra taken. A fundamental difference in the spectra between the bilayer films and alloy films was seen, suggesting the films are alloys, not herterogeneous mixtures.

A Study of Electron Paramagnetic Resonance and Optical Absorption Spectra of VO2+ Ions in Alkali Barium Phosphate Glasses

2003 ◽  
Vol 17 (16) ◽  
pp. 3033-3047 ◽  
Author(s):  
V. Ramesh Kumar ◽  
R. P. S. Chakradhar ◽  
A. Murali ◽  
N. O. Gopal ◽  
J. Lakshmana Rao
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Optical Absorption ◽  
Band Gap ◽  
Absorption Spectra ◽  
Optical Band Gap ◽  
Phosphate Glasses ◽  
Epr Spectra ◽  
Optical Absorption Spectra ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The electron paramagnetic resonance and optical absorption spectra of VO 2+ ions in different alkali barium phosphate glasses have been studied and the results have been analysed using C4v symmetry. The EPR spectrum shows eight hyperfine lines characteristic of VO 2+ ions. From the observed EPR spectra, the spin-Hamiltonian parameters, Fermi contact interaction parameter k, dipolar hyperfine coupling parameter P have been evaluated. The EPR spectra exhibit a marked concentration dependence. The EPR spectra were also recorded at different temperatures. The number of spins participating in resonance is found to be increasing with decreasing temperature. The paramagnetic susceptibility χ is calculated from the EPR data. As the temperature decreases, χ increases in accordance with Curie's law. The optical absorption spectrum exhibits two bands corresponding to the transitions 2B2g → 2B1g and 2B2g → 2Eg , characteristic of VO 2+ ions in octahedral symmetry with tetragonal distortion. From the ultraviolet edges of these optical absorption spectra, the optical band gap energies (Eopt) of the glass samples have been calculated. The optical band gap energy varies with alkali content. By correlating EPR and optical absorption data, the molecular orbital coefficients have been evaluated. The theoretical values of optical basicity of the glasses have also been evaluated.

Effect of Li2O and Na2O on Optical Properties of Bismuth Borate Glasses

2016 ◽  
Vol 675-676 ◽  
pp. 322-326
Author(s):  
Narong Sangwaranatee ◽  
Jakrapong Kaewkhao ◽  
Yotsakit Ruangtaweep
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Molar Volume ◽  
Absorption Spectra ◽  
Borate Glasses ◽  
Optical Absorption Spectra ◽  
Melt Quenching ◽  
Bismuth Borate ◽  
Work Effect

In this work, effect of Li2O and Na2O on bismuth borate glasses have been investigated. The glass samples were prepared in composition 44B2O3 : 50Bi2O3 : 5Li2O : 1A2O3 and 44B2O3 : 50Bi2O3 : 5Na2O3 : 1A2O3 (where A2O3= Sm2O3 and Dy2O3).Glasses were prepared using the melt-quenching technique at 1,100 oc under normal atmosphere. The result found that, the density and molar volume of lithium bismuth borate glasses are less than sodium bismuth borate glasses both in Sm2O3 and Dy2O3. In addition, the optical absorption spectra and luminescence of lithium bismuth borate glasses are higher than sodium bismuth borate glasses both in Sm2O3 and Dy2O3.

Optical Absorption of Doped and Undoped Bulk SiC

2000 ◽  
Vol 640 ◽  
Author(s):  
K. Miller ◽  
Q. Zhou ◽  
J. Chen ◽  
M. O. Manasreh ◽  
Z. C. Feng ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Optical Absorption ◽  
Band Gap ◽  
Absorption Spectra ◽  
Spectral Region ◽  
Sharp Peak ◽  
Band Edge ◽  
Optical Absorption Spectra ◽  
Bulk Silicon ◽  
Free Carriers

ABSTRACTOptical absorption spectra of undoped, n-type, and semi-insulating 6H and 4H bulk silicon carbide (SiC) were obtained in the spectral region of 200 – 3200 nm (6.20 – 0.3875 eV). Several features were observed in the absorption spectra collected for various samples. A sharp peak below the band gap was observed in 4H SiC. The intensity of this peak was observed to increase in samples that exhibit larger absorption due to free carriers, which leads us to conclude that the defect responsible for this peak is also the source of the free carriers in the materials. Additionally, a series of optical absorption peaks separated by approximately 21 meV were observed around 0.9185 eV (1350 nm). These peaks are zero phonon lines of intraband transitions in the VSi 3d shell. The optical absorption near the band edge was observed to be sample dependent. The variation of the band gap as a function of temperature is also observed to be sample dependent.

Novel electronic and optical properties of ultrathin silicene/arsenene heterostructures and electric field effects

2017 ◽  
Vol 19 (16) ◽  
pp. 10644-10650 ◽  
Author(s):  
Huabing Shu ◽  
Yilong Tong ◽  
Jiyuan Guo
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Electric Field ◽  
Band Gap ◽  
Absorption Spectra ◽  
Optical Absorption Spectra ◽  
Electric Field Effects ◽  
Electronic And Optical Properties ◽  
Vertical Electric Field ◽  
Variable Band Gap

The variable band-gap of the Si/As heterostructure (left) and optical absorption spectra for AA-stacking under a vertical electric field (right).

OPTICAL ABSORPTION IN AMORPHOUS THIN FILMS OF SnO2 DEPOSITED BY THERMAL EVAPORATION

2007 ◽  
Vol 21 (12) ◽  
pp. 2017-2032 ◽  
Author(s):  
M. ANWAR ◽  
S. A. SIDDIQI ◽  
I. M. GHAURI
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Band Gap ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Outward Diffusion ◽  
Optical Energy ◽  
Amorphous Thin Films

The fundamental absorption edge of SnO 2 amorphous thin films has been investigated. It has been observed that the optical energy gap decreases with the increase in film thickness, substrate temperature and post deposition annealing. The results are analysed by assuming optical absorption by non-direct transition. The decrease in optical band gap with increase in film thickness may be interpreted in terms of the incorporation of oxygen vacancies in the SnO 2 lattice. The decrease in optical energy due to the increase in substrate temperature may be ascribed to the release of trapped electrons by thermal energy or by the outward diffusion of the oxygen-ion vacancies, which are quite mobile even at low temperatures. The decrease in optical band gap due to annealing may be due to the formation of tin species of lower oxidation state.

Influence of Nano Filler (ZrO2) on Optical and Thermal Studies of Potassium Doped Polyethylene Oxide Solid Polymer Electrolytes

2022 ◽  
Vol 1048 ◽  
pp. 101-109
Author(s):  
Suresh Sripada ◽  
M. Chandrashekhar Reddy ◽  
T. Sreekanth ◽  
Rajesh Siripuram ◽  
K. Venkateshwarlu
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Polymer Electrolyte ◽  
Polyethylene Oxide ◽  
Polymer Electrolytes ◽  
Optical Band Gap ◽  
Thermal Studies ◽  
Fundamental Absorption Edge ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer

Solid polymer electrolyte films made with potassium doped Polyethylene oxide using ZrO2 as nanofiller (70PEO-30KBF4-x ZrO2 where x = 1, 2.5, 5, 7.5, & 10 wt% ­­) were prepared by solution casting technique. Optical and thermal properties of polymer electrolyte films were studied by using Optical absorption and DSC techniques. From Optical absorption spectra, it is observed that fundamental absorption edge is shifted towards the higher wavelength side (range 259- 297 nm) with increase of nano filler (ZrO­2) concentration (1-10 wt %). Optical band gap for all electronic transitions (p=1/2, 2, 2/3 and 1/3) are found to be increased as incorporation of nano filler (ZrO2) which confirms the structural rearrangements takes place in polymer electrolyte films. Optical band gap for indirect allowed transitions (p=1/2) are found to be in the range of 1.93-3.34eV. Decrease in Urbach energy (4.8eV- 1.4eV) is associated with decrease in defect formation in host polymeric matrix (PEO-KBF4) as a result of embedded nano filler (ZrO2). DSC spectra analysis of polymer electrolytes has showed melting temperatures in the range 63.63-73.71°C and highest crystallinity is found to be 85 % (10 wt % ZrO­2). Enthalpy values are elevated with increase in nanofiller composition (ZrO2) in the present polymer electrolyte films.Keywords: PEO based polymer electrolytes, Solid polymer electrolytes, Optical and Thermal studies.

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