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

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.

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


2017 ◽  
Vol 31 (13) ◽  
pp. 1750101 ◽  
Author(s):  
Ibrahim Bulus ◽  
S. A. Dalhatu ◽  
R. Hussin ◽  
W. N. Wan Shamsuri ◽  
Y. A. Yamusa

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.


1998 ◽  
Vol 53 (8) ◽  
pp. 927-932 ◽  
Author(s):  
G. A. Mousdis ◽  
G. C. Papavassiliou ◽  
A. Terzis ◽  
C. P. Raptopoulou

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.


1985 ◽  
Vol 40 (5) ◽  
pp. 511-515 ◽  
Author(s):  
G. Elbers ◽  
G. Lehmann

In vanadium-doped CsCl crystals grown from aqueous solutions anisotropic EPR spectra due to VO2+ are observed and analyzed at room temperature. Evidence is presented that isotropic spectra of this ion observed in this and other compounds are due to inclusions of growth solution and not to rapid rotation of the vanadyl ion in the solid as normally assumed. At 77 K a well resolved vibrational progression of about 820 cm −1 is observed in the first ligand field band of this ion. The optical absorption spectra indicate the presence of a second valence state of vanadium, most likely V3+, in varying proportions depending on the crystal growth temperature.


2021 ◽  
Vol 27 (1) ◽  
pp. 84-89
Author(s):  
Waramon LANGLAR ◽  
Areeya AEIMBHU ◽  
Pichet LIMSUWAN ◽  
Chesta RUTTANAPUN

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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