Preparation and Characterization of (C6H5CH2CH2NH3)4BiI7 · H2O, (C6H5CH2CH2NH3)3BiBr6 and (C6H5CH2CH2NH3)3BiCl6

1995 ◽  
Vol 50 (10) ◽  
pp. 1566-1569 ◽  
Author(s):  
G. C. Papavassiliou ◽  
I. B. Koutselas ◽  
A. Terzis ◽  
C. P. Raptopoulou

The title compounds were prepared and characterized analytically, structurally, and spectroscopically. They contain isolated BiX6 (X = I. Br, Cl) anions. Their optical absorption spectra show excitonic bands in the UV-visible spectral region. These bands occur at higher energies than the corresponding bands of R3M2X9 (R = MemNH4-m; m = 1,2, 3, 4).

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


2013 ◽  
Vol 68 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Jian Zhou ◽  
Xing Liu ◽  
Feilong Hu

Three new lanthanide thioantimonates(V) [Ln(en)(teta)(SbS4)] {Ln=Sm (1), Eu (2), Gd (3); en=ethylenediamine; teta=triethylenetetramine} have been solvothermally synthesized and structurally characterized. Compounds 1 - 3 are isostructural. The [SbS4]3- anion acting as bichelating ligand is bound to the [Ln(en)(teta)]3+ ion, resulting in a neutral complex [Ln(en)(teta)(SbS4)]. The central Ln3+ ion lies within an eight-coordinate environment forming a distorted bicapped trigonal prism LnN6S2. Although a few lanthanide thioantimonates have been reported to date, they only contain one type of ethylene polyamine. Compounds 1 - 3 are rare examples of lanthanide thioantimonates with mixed ethylene polyamine ligands. The absorption edges of 1:75 eV for 1 and 2:27 eV for 3 have been derived from optical absorption spectra.


2000 ◽  
Vol 640 ◽  
Author(s):  
K. Miller ◽  
Q. Zhou ◽  
J. Chen ◽  
M. O. Manasreh ◽  
Z. C. Feng ◽  
...  

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.


2014 ◽  
Vol 979 ◽  
pp. 135-138 ◽  
Author(s):  
Yotsakit Ruangtaweep ◽  
Jakrapong Kaewkhao

In this work, the physical and optical properties of soda-lime-borate glasses doped with V2O5 concentration of 0.0 to 2.5 in mol% have been investigated. The glass samples were prepared by the normal melt-quench technique. The results show that the density and refractive index decreased with additional 0.5 mol% content of V2O5. Then both results increased with increasing V2O5 content from 1.0-2.5 mol%. The optical absorption spectra of glass samples were measured by UV-visible spectrophotometer in the wavelength range 300-1100 nm and color coordinate in CIEL*a*b* system. The absorption peaks locate around 605 and 960 nm for all V2O5 concentration that are associated to V4+ ions and produce the brown color.


2017 ◽  
Author(s):  
◽  
M. L. Alvarado-Noguez1

Photoacoustic Spectroscopy (PAS) stand outs among Photothermal techniques due to its versatility for the characterization of different types of materials, including biological samples. In this study, were compared and analyzed by PAS, the differences between the optical absorption spectra of blood of male Fisher rats, in three cases, control (healthy rats), liver damage and liver damage treated with Curcuma longa. The experimental results show differences in the optical absorption spectra of each analysed case, therefore PAS would be proposed as a non conventional complementary technique, to study the effect of Curcuma longa in induced liver damage for an animal model.


2013 ◽  
Vol 770 ◽  
pp. 307-310 ◽  
Author(s):  
Wichian Siriprom ◽  
Kanyakorn Teanchai ◽  
Onanong Chamlek ◽  
Sirisit Sukphirom ◽  
Yotsakit Ruangtaweep ◽  
...  

In this work, effects of Ni2+ ions on soda lime silicate glasses have been investigated. Glasses were prepared in formula (65-x)SiO2 : 25Na2O : 10CaO: xNiO (where x is 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 mol%). The densities of glasses not depend on Ni2+ concentration. The refractive indices decreased with increasing of NiO concentration. The optical absorption spectra were measured by uv-visible spectrophotometer and show peaks correspond with Ni2+ in glass matrices. Both of octahedral transitions and tetrahedral transition from Ni2+ ion were found around 450 and 625 nm respectively. The color of glasses were also measured in CIE L* a* b* system.


2016 ◽  
Vol 675-676 ◽  
pp. 318-321
Author(s):  
Wichian Siriprom ◽  
Kanyakorn Teanchai ◽  
Nattapon Srisittipokakun ◽  
Jakrapong Kaewkhao

In this work, effects of CoO on silicoborate glasses have been investigated. Glasses were prepared in formula (53-x)B2O3:11SiO2:32SrO:1Bi2O3:1TiO2: xCoO (where x is 0.00, 0.01, 0.02, 0.03, 0.04 and 0.05 mol%). The results show that, the density and refractive index were increased with increasing of CoO concentration. The optical absorption spectra were measured by UV-Visible Spectrophotometer and show peaks correspond with Co2+ in glass matrices at a wavelength of around 511 584 and 649 nm for all glass samples.


1989 ◽  
Vol 164 ◽  
Author(s):  
K. L. Moran ◽  
W. T. A. Harrison ◽  
T. E. Gier ◽  
J. E. Mac Dougall ◽  
G. D. Stucky

AbstractSolid-state chemistry has been used to control both the size and the interconnection distance of small II-VI semiconductor moeities incorporated in zeolitic hosts with the sodalite-type structure. Structural characterization was carried out using X-ray Rietveld powder methods, and optical properties of these materials were also measured. These novel materials show quantum superlattice effects as evidenced by blue shifts in their optical absorption spectra.


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