Improved analysis of atmospheric absorption spectra by including the temperature dependence of NO2

1996 ◽  
Vol 101 (D15) ◽  
pp. 20945-20952 ◽  
Author(s):  
R. W. Sanders
Keyword(s):  
Temperature Dependence ◽  
Absorption Spectra ◽  
Atmospheric Absorption

Temperature dependence of the absorption spectra in CdTe-doped glasses

1999 ◽  
Vol 14 (1) ◽  
pp. 58-63 ◽  
Author(s):  
M L Redígolo ◽  
W A Arellano ◽  
L C Barbosa ◽  
C H Brito Cruz ◽  
C L Cesar ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Absorption Spectra ◽  
Doped Glasses

The origins of the colours of natural yellow, blue, and green sapphires

1972 ◽  
Vol 25 (7) ◽  
pp. 1371 ◽  
Author(s):  
J Ferguson ◽  
PE Fielding
Keyword(s):  
Temperature Dependence ◽  
Absorption Spectra ◽  
Excited States ◽  
Exchange Parameter ◽  
Nearest Neighbour ◽  
Electronic Excitations ◽  
Heisenberg Exchange ◽  
Synthetic Crystals

An analysis of the absorption spectra of natural yellow sapphires shows that the absorption is due to single Fe3+ ions and pairs of ions Fe3+-O2--Fe3+. Assignments of all levels from the 4G, 4P, and 4D have been made as well as four simultaneous electronic excitations of a pair of ions. The temperature dependence of the intensity of the pair absorption shows that one pair is mainly involved, probably the fourth- nearest neighbour pair. The value of the Heisenberg exchange parameter (J Sa. Sb) lies in the range 30-40 K. Estimates of this parameter for various excited states have been made. Synthetic yellow sapphires have spectra which duplicate the natural specimens. Blue and green natural sapphires have, in addition to the bands present in the spectra of yellow sapphires, spectra with bands at 17800 (┴C), 14200 (//c), 11500 (┴C), and 10000 om-1 (//c). The first two can be linked to Fe,Ti pairs and the evidence favours the nearest neighbour pair Ti4+-O2?Fe2+ for the 17800 cm-1 band and possibly the first neighbour pair for the 14200 cm-1 band. The second two can be produced in synthetic crystals by growth from fluoride-containing flux and the evidence supports an explanation involving second-nearest neighbour pairs Fe2+- O2--Fe3+ for the 11500 cm-1 absorption and first neighbours for the 10000 om-1 absorption.

Optical Spectroscopy of Mixed Metamagnetic FexCo1-xCl2 Crystals

1980 ◽  
Vol 35 (10) ◽  
pp. 1013-1019 ◽  
Author(s):  
Friedrich Seitz ◽  
Terence E. Wood ◽  
Peter Day
Keyword(s):  
Charge Transfer ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Absorption Spectra ◽  
Optical Spectroscopy ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Broad Band ◽  
Mixed Crystals ◽  
Magnetic Exchange

Abstract Electronic absorption spectra are reported for single crystals of composition FexCo1-xCl2 as a function of temperature from 300 K to 4 K. A broad band at 436 nm is assigned to Fe (II) → Co (II) charge transfer and the temperature dependence of its intensity is related to the magnetic exchange between the ions. The 2T1g(2H) excitation of Co (II) in the mixed crystals has an unusual temperature dependence which correlates with the Néel temperature.

Temperature Dependence of Integrated Intensities of Vibrational Bands in M2GeF6IR-Absorption Spectra

1978 ◽  
Vol 11 (11) ◽  
pp. 877-890 ◽  
Author(s):  
Y. I. Sergienko ◽  
L. N. Ignatieva ◽  
P. S. Gordienko ◽  
M. F. Eiberman ◽  
S. F. Bogdan
Keyword(s):  
Temperature Dependence ◽  
Absorption Spectra ◽  
Vibrational Bands ◽  
Integrated Intensities

Second Moment Simulations for Different Models of Rotations and Oscillations in Polycrystalline Thiourea Pyridinium Nitrate Inclusion Compound and its Two Perdeuterated Analogues

2005 ◽  
Vol 60 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Roman Goc ◽  
Aleksandra Pajzderska ◽  
Jan Wᶏsicki
Keyword(s):  
Temperature Dependence ◽  
Absorption Spectra ◽  
Inclusion Compound ◽  
Experimental Results ◽  
Second Moment ◽  
Potential Barriers ◽  
H Nmr ◽  
Three Samples ◽  
Wide Range ◽  
Insight Into

The second moment of 1H NMR absorption spectra was calculated for three samples of [(NH2)2CS]2(C5H5NH)+NO3−, two of which were deuterated at different positions. The calculations were performed for different rotations and oscillations, and for a wide range of frequencies of these motions. These frequencies were then transformed into temperatures resulting in the temperature dependence of the second moment. The calculations were undertaken in order to analyze the experimental results obtained in our laboratory. Special attention was paid to molecular reorientations through unequal potential barriers. Comparison of the second moment values calculated for different models of rotation with the experimental ones enabled a deeper insight into the internal motion in this material as a function of temperature.

Non-Markovian Dynamic And Nmr Spectra In Solids

2004 ◽  
Vol 59 (7-8) ◽  
pp. 501-504 ◽  
Author(s):  
M. Olszewski ◽  
N. A. Sergeev ◽  
A.V. Sapiga
Keyword(s):  
Markov Model ◽  
Temperature Dependence ◽  
Absorption Spectra ◽  
Nmr Spectra ◽  
Molecular Motion ◽  
Molecular Motions ◽  
Dichotomic Noise

The influence of non-Markov molecular motions on NMR absorption spectra has been investigated. It has been shown that the simple non-Markov model of water molecular motion with fluctuations driven by dichotomic noise very well explains the observed temperature dependence of NMR spectra in the mineral natrolite. - PACS number: 05.40.+j, 33.25.+k, 76.20.+q

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