scholarly journals Optical absorption of LiNaGe4O9:Mn crystal

2021 ◽  
Vol 29 (1) ◽  
pp. 69-72
Author(s):  
A. Yu. Osetsky ◽  
T. V. Panchenko ◽  
M. D. Volnianskii ◽  
M. P. Trubitsyn
Keyword(s):  
Field Theory ◽  
Optical Absorption ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Optical Absorption Spectra ◽  
Crystal Field Theory ◽  
Absorption Bands ◽  
Additional Absorption ◽  
Impurity Ions ◽  
Semi Empirical

The paper reports the results of optical absorption spectra studying in LiNaGe4O9 crystal doped with Mn. It is shown that Mn impurity causes the appearance of the additional absorption bands. The intensities of these bands change in different ways in the range of the ferroelectric phase transition. Semi-empirical version of the crystal field theory is used to discuss localization and charge state of Mn impurity ions in the LiNaGe4O9 structure.

Optical Absorption and Photoluminescence Properties of Dy3+ Ions in Bi2O3-SiO2-B2O3 Glass System

2014 ◽  
Vol 979 ◽  
pp. 280-284
Author(s):  
Narong Sangwaranatee ◽  
Yaowaluk Tariwong ◽  
Sunisa Sarachai ◽  
Jakrapong Kaewkhao ◽  
Natthakridta Chanthima
Keyword(s):  
Optical Absorption ◽  
Emission Spectrum ◽  
Molar Volume ◽  
Borosilicate Glass ◽  
Excitation Wavelength ◽  
Optical Absorption Spectra ◽  
Photoluminescence Spectra ◽  
Photoluminescence Properties ◽  
Melt Quenching ◽  
Absorption Bands

This research studied the effect of dysprosium on the physical, optical and luminescence properties of the bismuth borosilicate glass in compositions 40Bi2O3 : 20SiO2 : (40-x)B2O3 : xDy2O3 (where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%). The glass systems have been prepared at 1100 °C by melt quenching technique. The results showed that the density and molar volume of glass samples are between 4.6477 ± 0.0020 to 5.0047 ± 0.0041 g/cm3 and 45.6608 to 48.6797 cm3/mol, respectively. The values of density and molar volume of these glasses were not depend on the Dy2O3 concentration. The optical absorption spectra of glass samples in the UV-Vis-NIR region shows absorption bands at 794, 906, 1094, 1276 and 1690 nm, respectively. The photoluminescence spectra show emission bands at 482 (blue), 576 (green), 663 (yellow) and 756 (red) nm under 453 nm excitation wavelength. The emission spectrum at 576 nm has shown a strongest intensity.

Excitonic Bands in the Optical Absorption Spectra of A3MX6 and A3M2X9 (A = MeNH3, Me2NH2, Me3NH, Me4N; M = Bi, Sb; X = Cl, Br, I)

1994 ◽  
Vol 49 (6) ◽  
pp. 849-851 ◽  
Author(s):  
G. C. Papavassiliou ◽  
I. B. Koutselas
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Spectral Region ◽  
Visible Spectral Region ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
Uv Visible ◽  
Low Dimensional

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

Paramagnetic resonance and optical absorption of trapped holes and electrons in irradiated KCI: Ag

1963 ◽  
Vol 271 (1345) ◽  
pp. 243-267 ◽  
Keyword(s):  
Electron Spin Resonance ◽  
Low Temperature ◽  
Optical Absorption ◽  
Electron Spin ◽  
Optical Absorption Spectra ◽  
Paramagnetic Resonance ◽  
Spin Resonance ◽  
Impurity Ions ◽  
Temperature Irradiation ◽  
Positive Holes

The electron spin resonance and optical absorption spectra of crystals of KCl containing silver impurity ions were examined after the crystals had been X -irradiated at 77 °K. It is shown that the silver impurity ions act as traps for both electrons and positive holes. A description is given of the annealing behaviour of the crystals after low-temperature irradiation.

The role of dysprosium ions on the physical and optical properties of lithium-borosulfophosphate glasses

2017 ◽  
Vol 31 (13) ◽  
pp. 1750101 ◽  
Author(s):  
Ibrahim Bulus ◽  
S. A. Dalhatu ◽  
R. Hussin ◽  
W. N. Wan Shamsuri ◽  
Y. A. Yamusa
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Physical Parameters ◽  
Potential Candidate ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
X Ray ◽  
Nir Absorption ◽  
Optical Applications

Achieving outstanding physical and optical properties of borosulfophosphate glasses via controlled doping of rare earth ions is the key issue in the fabrication of new and highly-efficient glass material for diverse optical applications. Thus, the effect of replacing P2O5 by Dy2O3 on the physical and optical properties of Dy[Formula: see text]-doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O–30B2O3–15SO3–[Formula: see text]P2O5–[Formula: see text]Dy2O3 (where 0.0 mol.% [Formula: see text] mol.%) has been investigated. The glass samples were synthesized from high-purity raw materials via convectional melt-quenching technique and characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), density and UV–vis–NIR absorption measurements. The amorphous nature of the prepared glass samples was confirmed by XRD patterns whereas the EDX spectrum depicts elemental traces of O, C, B, S, P and Dy. The physical parameters such as density, refractive index, molar volume, polaron radius and field strength were found to vary nonlinearly with increasing Dy2O3 concentration. UV–vis–NIR absorption spectra revealed seven absorption bands with most dominant peak at 1269 nm (6H[Formula: see text]F[Formula: see text]H[Formula: see text]). From the optical absorption spectra, the optical bandgap and Urbach’s energy have been determined and are related with the structural changes occurring in these glasses with increase in Dy2O3 content. Meanwhile, the bonding parameters ([Formula: see text]) evaluated from the optical absorption spectra were found to be ionic in nature. The superior features exhibited by the current glasses nominate them as potential candidate for nonlinear optical applications.

Notizen: Preparation, Structures and Optical Properties of [H3N(CH2)6NH3]BiX5 (X=I, Cl) and [H3N(CH2)6NH3]SbX5 (X=I, Br)

1998 ◽  
Vol 53 (8) ◽  
pp. 927-932 ◽  
Author(s):  
G. A. Mousdis ◽  
G. C. Papavassiliou ◽  
A. Terzis ◽  
C. P. Raptopoulou
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Crystal Structures ◽  
Absorption Spectra ◽  
Blue Shift ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
One Dimensional ◽  
Excitonic Absorption

Abstract The preparation, crystal structures and optical absorption spectra of [H3N(CH2)6NH3]BiX5 (X= I, Cl) and [H3N(CH2)6NH3]SbX5 (X =I, Br) are reported. The anions of the compounds consist of MX6-octahedra (M =Bi, Sb) sharing cisvertices in one-dimensional zig-zag chains. Because of their one-dimensional character, a blue shift of the excitonic absorption bands, in com parison to those of higher dim ensionality systems (MX3), is observed.

scholarly journals A computational thermochemical value for Cr-Cu bond dissociation energy: using crystal field theory to understand the chemical bond in metal clusters

2020 ◽  
Author(s):  
Robson de Farias
Keyword(s):  
Field Theory ◽  
Bond Dissociation Energy ◽  
Dissociation Energy ◽  
Unpaired Electron ◽  
Metal Clusters ◽  
Strong Field ◽  
Crystal Field Theory ◽  
Bond Dissociation ◽  
Semi Empirical ◽  
Experimental Reference

<div> <p>Semi-empirical (PM6) approach was employed to modelling Cr-Cu dimmer. The obtained bond dissociation energy for such specie agrees very well with experimental/reference values. It was verified that in the Cr-Cu dimmer, chromium has only one unpaired electron, meaning that copper behaves, in such dimmer, as a strong field ligand. Such results strongly suggest that 1:1 Cr-Cu bronzes must behave as a one unpaired electron compound and not a five unpaired electrons one, with, of course, remarkable influences on their magnetic properties.</p> </div>

Optical Absorption Spectra of KBr:Pb2+ Crystals

1973 ◽  
Vol 51 (21) ◽  
pp. 2242-2248 ◽  
Author(s):  
Robert E. Chaney ◽  
P. W. M. Jacobs ◽  
Taiju Tsuboi
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Alkali Halide ◽  
Room Temperature ◽  
Nonlinear Least Squares ◽  
Energy Separation ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
Fundamental Properties ◽  
Alkali Halide Crystals

The fundamental properties of the absorption spectra of KBr:Pb2+ crystals have been studied at various temperatures from the liquid helium range to room temperature. The observed absorption bands are assigned to the so-called A, B, C, and D' bands by analogy with the absorption bands of other s2-configuration ions in alkali halide crystals. The B, C, and D′ bands overlap but have been resolved into their components by nonlinear least squares analysis. A discussion is given of the energy separation between the B and C bands in Sn2+-, Tl+-, and Pb2+-doped alkali halide crystals.

scholarly journals Excitonic Bands in the Optical Absorption Spectra of (Bu4N)CuBr2, (Et4N)2Cu2Br4, (Pr4N)2Cu4Br6, (Bu4N)2Cu2I4, (Me4N)Cu2I3, (Pr4N)4Ag4I8, (Me4N)Ag2I3, (Et4N)Ag2Br3, and Similar Compounds

1999 ◽  
Vol 54 (1) ◽  
pp. 109-112 ◽  
Author(s):  
G. C. Papavassilioua ◽  
G. A. Mousdis ◽  
A. Terzis ◽  
C. P. Raptopoulou
Keyword(s):  
Optical Absorption ◽  
Spectral Region ◽  
Quantum Confinement ◽  
Optical Absorption Spectra ◽  
Bulk Materials ◽  
Trivalent Metal ◽  
Absorption Bands ◽  
Bivalent Metal ◽  
Halide Complexes ◽  
Low Dimensional

The title compounds (natural low-dimensional semiconductor systems) exhibit strong excitonic optical absorption bands in the UV spectral region, because of the quantum confinement of excitons, as in the cases of bivalent-metal and trivalent-metal halide complexes. The excitonic bands are shifted to longer wavelengths, approaching those of the corresponding bulk materials, as the anion-size or the anion-dimensionality increases.

scholarly journals Microwave and Induction Heating-Assisted Biosynthesis of 12CaO 7Al2O3 Electride from Aloe Vera Leaf Extract

2021 ◽  
Vol 27 (1) ◽  
pp. 84-89
Author(s):  
Waramon LANGLAR ◽  
Areeya AEIMBHU ◽  
Pichet LIMSUWAN ◽  
Chesta RUTTANAPUN
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Induction Heating ◽  
Aloe Vera ◽  
Process Time ◽  
Heating Process ◽  
Microwave Assisted Synthesis ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
Precursor Powders

The white powders used as precursor powders for the synthesis of 12CaO×7Al2O3 electride (C12A7:e-) were prepared by biosynthesis method using Aloe vera extract and microwave assisted synthesis. The C12A7:e- crystals were synthesized by induction heating process under a reducing atmosphere at different times of 3, 4 and 5 min. The structure of C12A7:e- powders was characterized by X-ray diffraction. The XRD analysis revealed that pure C12A7:e- powders were obtained from white precursor powders with an induction heating process time of 5 min. To confirm that the white precursor powders were transformed into C12A7:e- after induction heating process for 3, 4 and 5 min, the optical absorption spectra of powders were investigated by an UV-Vis diffuse reflectance spectrometer in the wavelength range of 200 – 800 nm. The results show the optical absorption bands at 2.8 eV for the white precursor powders with induction heating time of 3, 4 and 5 min. This is due to the C12A7 was transformed into electride (C12A7:e-). Therefore, the results on the optical absorption spectra are in good agreement with the XRD results.

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