THE OPTICAL ABSORPTION SPECTRA OF SOME ANDRADITES AND THE IDENTIFICATION OF THE 6A1→4A14E(G) TRANSITION IN OCTAHEDRALLY BONDED Fe3+

1967 ◽  
Vol 4 (6) ◽  
pp. 1039-1047 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Electronic Transitions ◽  
Optical Absorption Spectra ◽  
Independent State ◽  
Field Independent ◽  
Impurity Ions

The optical absorption spectra of andradites from three different localities are reported. The spectra show a very sharp d–d band at 22 700 cm−1 (440 mμ) that has been assigned to electronic transitions to the first field-independent state (4A14E(G)) in octahedrally bonded Fe3+. A strong broad d–d absorption at 19 000 cm−1 in the high-Ti andradite (melanite) has been assigned to octahedrally bonded Ti3+. The andradites also show broad bands at 12 500 cm−1, 16 500 cm−1, and 21 400 cm−1 that are part of the Fe3+ spectrum.The andradite spectra have been compared to the spectrum of an almandine-pyrope. The conclusion is reached that the Fe3+ octahedra in andradite and the pyralspite garnets are different. There is no justification, therefore, in giving an almandine-pyrope (that contains Fe3+) an andradite content on the basis of Fe3+ analyses. The Fe3+ atoms in pyralspites are better regarded as impurity ions.

Electronic Transitions in a Classical Antiferroelectric Banana-Shaped Compound

2010 ◽  
Vol 428-429 ◽  
pp. 317-321
Author(s):  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Liquid Crystal ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Ethyl Alcohol ◽  
Electronic Structures ◽  
Tight Binding ◽  
Methyl Benzoate ◽  
Electronic Transitions ◽  
Optical Absorption Spectra ◽  
Dilute Solutions

The electronic transitions in a classical banana-shaped liquid crystal 1,3-phenylene-bis [4-(4-octylphenylimino) methyl] benzoate have been investigated by measuring its optical absorption spectra in dilute solutions of ethyl alcohol and by calculating its electronic structures with extended Hückel tight binding program. The banana-shaped compound shows strong absorptions at 240, 280, 350 nm, respectively. On the basis of the calculated electronic structures, the three strong absorptions can be assigned to the *, n*, and nn* electronic transitions in this banana-shaped compound.

Optical absorption spectra of octahedrally bonded Fe3+ in vesuvianite

1968 ◽  
Vol 5 (1) ◽  
pp. 89-92 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Optical Absorption ◽  
Energy Range ◽  
Absorption Spectra ◽  
Excited States ◽  
Ground State ◽  
Electronic Transitions ◽  
Optical Absorption Spectra ◽  
Sharp Band ◽  
Individual Bands ◽  
The Individual

The optical absorption spectra of green vesuvianite crystals from Lowell County, Vermont, are reported in the energy range 12 000 cm−1 to 30 000 cm−1. The principal absorptions have been attributed to octahedrally bonded Fe3+ and the individual bands have been assigned to spin-forbidden electronic transitions from the 6A1 ground state to excited states in Fe3+. In particular, the 6A1 → 4A14E(G) transition is marked by a relatively sharp band at 21 600 cm−1.

Optical Absorption Study of Hydrogen In Zn-Doped Si

1998 ◽  
Vol 513 ◽  
Author(s):  
M. Suezawa
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Hydrogen Atmosphere ◽  
Electronic Transitions ◽  
Optical Absorption Spectra ◽  
Hydrogen Atoms ◽  
Ir Spectrometry ◽  
Co Doping ◽  
Ft Ir ◽  
Hydrogen Bound

ABSTRACTWe studied the interaction between hydrogen (H) and Zn or Zn-related defects in Zn-doped Si crystals from the measurements of optical absorption spectra of hydrogen bound to Zn or Znrelated defects. We doped Si crystals with Zn by annealing the crystals in Zn vapor at 1200°C followed by quenching. After Zn-doping, we doped specimens with H by annealing them in a hydrogen atmosphere followed by quenching. We measured optical absorption spectra of the above specimens at about 6 K by means of FT-IR spectrometry. Many optical absorption peaks were observed; some are due to electronic transitions and some are due to vibrational transitions of H vibration. Hydrogen atoms are known to passivate Zn acceptors since the optical absorption intensity associated with electronic transitions become much weaker after hydrogenation. Absorption peaks associated with H vibration are known to be related to complexes composed of one Zn atom and two hydrogen atoms. We concluded this from studies on the effect of co-doping with H and deuterium and the effect of Zn isotopes on the optical absorption spectra due to H.

scholarly journals Fast optical absorption spectra calculations for periodic solid state systems

2020 ◽  
Vol 15 (1) ◽  
pp. 89-113
Author(s):  
Felix Henneke ◽  
Lin Lin ◽  
Christian Vorwerk ◽  
Claudia Draxl ◽  
Rupert Klein ◽  
...  
Keyword(s):  
Solid State ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Absorption Spectra

NIR and Upconversion Luminescence Properties of Nd3+ Doped in Gd2O3-CaO-SiO2-B2O3 Glass System

2014 ◽  
Vol 548-549 ◽  
pp. 124-128 ◽  
Author(s):  
S. Insiripong ◽  
S. Kaewjeang ◽  
U. Maghanemi ◽  
H.J. Kim ◽  
N. Chanthima ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Concentration Quenching ◽  
Luminescence Spectra ◽  
Optical Absorption Spectra ◽  
Glass Matrices ◽  
Nir Luminescence

In this work, properties of Nd3+ in Gd2O3-CaO-SiO2-B2O3 glass systems with composition 25Gd2O3-10CaO-10SiO2-(55-x)B2O3-xNd2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% were investigated. The optical absorption spectra show peaks at 4F3/2 (877 nm) , 4F5/2+2H9/2 (802 nm), 4F7/2+4S3/2 (743 nm), 4F9/2 (682 nm), 2H11/2 (627 nm), 2G7/2 +4G5/2 (582 nm), 4G7/2 +2K13/2 (527 nm), 4G11/2 (481 nm), 2P1/2 (427 nm) and 2L15/2 + 4D1/2 + 1I11/2+ 4D5/2+ 4D3/2 (355 nm) reflecting the Nd3+ ions in glass matrices. The densities were increased with increasing of Nd2O3 concentration. This indicates the increase of the molecular weight by the replacement of B2O3 with a heavier Nd2O3 oxide in the glass. The upconversion luminescence spectra show bands at 393 nm for all Nd2O3 concentration and the strongest intensity from 2.5 % mol of Nd2O3 was obtained. For NIR luminescence, the intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1.5 mol% and beyond 1.5 mol% the concentration quenching is observed.

OPTICAL ABSORPTION SPECTRA OF ARSENIC AND PHOSPHORUS IN SILICON

1962 ◽  
Vol 40 (10) ◽  
pp. 1480-1489 ◽  
Author(s):  
J. W. Bichard ◽  
J. C. Giles
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Excited States ◽  
Ground State ◽  
Absorption Lines ◽  
Full Width ◽  
Optical Absorption Spectra ◽  
Phosphorus Impurity ◽  
Line Widths ◽  
Phosphorus In Silicon

The optical absorption spectra of arsenic and phosphorus donor impurities in silicon have been studied under conditions of improved resolution. Absorption lines due to transitions from the impurity ground state to the excited states 2p0, 2p±, 3p0, 3p±, 4p0, 4 p±, and 5p0, and 5p± have been observed at 4.2° K. The relative intensities of some of these absorption lines are compared with existing experimental and theoretical estimates. The contribution of instrumental broadening to the observed line widths is assessed and natural line widths are estimated. The estimates indicate values for the natural line widths which are much less than those previously reported. For phosphorus impurity, the natural line widths are estimated to be less than 0.08 × 10−3 electron volts full width at half-maximum. The possibility of concentration broadening is discussed in connection with the arsenic data.

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