INFRARED ABSORPTION OF DEUTERIUM INDUCED BY INTERMOLECULAR FORCES

1965 ◽  
Vol 43 (5) ◽  
pp. 793-799 ◽  
Author(s):  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Absorption Band ◽  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Room Temperature ◽  
Intermolecular Forces ◽  
Absorption Coefficients ◽  
Fundamental Band ◽  
Molecular Parameters ◽  
The Individual ◽  
Gas Pressures

The pressure-induced fundamental infrared absorption band of deuterium has been investigated in the pure gas for gas pressures up to 250 atm at room temperature. The binary and ternary absorption coefficients were determined from the integrated absorption coefficients of the fundamental band at different densities of the gas. The splitting of the Q branch into two well-resolved components QP and QR was observed; the contours also exhibit pronounced S(0) and S(2) components with an indication of the S(1) and O(2) components. The existing theory and the available molecular parameters of deuterium were used to calculate the binary absorption coefficients of the individual lines of the O and S branches and of the quadrupole part of the Q branch. From these calculations and the experimental value of the total binary absorption coefficient of the fundamental band, the overlap part of the binary absorption coefficient of the Q branch was estimated.

INDUCED INFRARED ABSORPTION OF DEUTERIUM IN DEUTERIUM – FOREIGN GAS MIXTURES

1966 ◽  
Vol 44 (11) ◽  
pp. 2893-2903 ◽  
Author(s):  
S. T. Pai ◽  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Absorption Band ◽  
Binary Mixtures ◽  
Infrared Absorption ◽  
Room Temperature ◽  
The Other ◽  
Absorption Profile ◽  
Absorption Coefficients ◽  
Helium Mixtures ◽  
Experimental Values ◽  
The Individual

The pressure-induced fundamental infrared absorption band of deuterium was studied in deuterium–helium, deuterium–argon, and deuterium–nitrogen mixtures at pressures up to 1 200 atm at room temperature. The enhancement absorption profile of each mixture shows a well-resolved splitting of the Q branch into two components QP and QR. While the enhancement contours of deuterium–helium mixtures do not exhibit any absorption peaks corresponding to the O and S branches, those of the other two binary mixtures show a pronounced S(2) peak and an indication of several other O and S peaks of the band. Integrated absorption coefficients of the band have been measured for all the mixtures, and the binary and ternary absorption coefficients were determined. The theory of Van Kranendonk and the available molecular parameters of deuterium and the perturbing gases were used to calculate the binary absorption coefficients of the individual lines of the O and S branches and of the quadrupole part of the Q branch of the band in all three binary mixtures. Using these calculated values and the experimental values of the total binary absorption coefficients of these mixtures, the overlap parts of the binary absorption coefficients of the Q branch were estimated.

Further studies on the collision-induced absorption of the fundamental band of hydrogen at room temperature

1969 ◽  
Vol 47 (24) ◽  
pp. 2745-2751 ◽  
Author(s):  
G. Varghese ◽  
S. Paddi Reddy
Keyword(s):  
Binary Mixture ◽  
Infrared Absorption ◽  
Path Length ◽  
Room Temperature ◽  
Absorption Coefficients ◽  
Fundamental Band ◽  
Induced Absorption ◽  
Two Peaks

The collision-induced infrared absorption of the fundamental band of hydrogen in H2–O2 and H2–Xe mixtures was studied at room temperature at a path length of 105.2 cm at pressures up to 250 atm for different base pressures of hydrogen. The enhancement absorption profiles of the band in H2–O2 mixtures show the usual features of collision-induced absorption. However, the enhancement profiles in H2–Xe mixtures show some interesting new features. These are: the separation between the peaks of the two components of the Q branch remains almost constant with increasing density of the mixture; at all densities, the intensities of these two peaks are almost equal; and the lines of the quadrupolar branches O and S are more pronounced than those in any other binary mixture of hydrogen studied previously. Integrated absorption coefficients were measured for each of the mixtures and the binary and ternary absorption coefficients were derived. The values of the binary coefficients are 6.12 × 10−35 cm6 s−1 for H2–O2, and 11.34 × 10−35 cm6 s−1 for H2–Xe. The ternary coefficient is zero for H2–O2, whereas it has a large negative value for H2–Xe.

scholarly journals Infrared Absorption and Its Sources of CdZnTe at Cryogenic Temperature

2022 ◽  
Author(s):  
Hiroshi Maeshima ◽  
Kosei Matsumoto ◽  
Yasuhiro Hirahara ◽  
Takao Nakagawa ◽  
Ryoichi Koga ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Wavelength Region ◽  
Room Temperature Resistivity ◽  
Absorption Model ◽  
Acceptor Level ◽  
Absorption Coefficients ◽  
Temperature Resistivity

AbstractTo reveal the causes of infrared absorption in the wavelength region between electronic and lattice absorptions, we measured the temperature dependence of the absorption coefficient of p-type low-resistivity ($$\sim 10^2~ \Omega \mathrm{cm}$$ ∼ 10 2 Ω cm ) CdZnTe crystals. We measured the absorption coefficients of CdZnTe crystals in four wavelength bands ($$\lambda =6.45$$ λ = 6.45 , 10.6, 11.6, 15.1$$~\mu $$ μ m) over the temperature range of $$T=8.6$$ T = 8.6 -300 K with an originally developed system. The CdZnTe absorption coefficient was measured to be $$\alpha =0.3$$ α = 0.3 -0.5 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=300$$ T = 300 K and $$\alpha =0.4$$ α = 0.4 -0.9 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=8.6$$ T = 8.6 K in the investigated wavelength range. With an absorption model based on transitions of free holes and holes trapped at an acceptor level, we conclude that the absorption due to free holes at $$T=150$$ T = 150 -300 K and that due to trapped-holes at $$T<50$$ T < 50 K are dominant absorption causes in CdZnTe. We also discuss a method to predict the CdZnTe absorption coefficient at cryogenic temperature based on the room-temperature resistivity.

scholarly journals Pressure-induced infrared absorption of the fundamental band of hydrogen in H2–Ne and H2–Kr mixtures at room temperature

1968 ◽  
Vol 46 (12) ◽  
pp. 1373-1379 ◽  
Author(s):  
S. Paddi Reddy ◽  
W. F. Lee
Keyword(s):  
Infrared Absorption ◽  
Path Length ◽  
Room Temperature ◽  
Absorption Coefficients ◽  
Fundamental Band ◽  
Low Pressures

The pressure-induced infrared absorption of the fundamental band of hydrogen in H2–Ne and H2–Kr mixtures was studied at room temperature at a path length of 25.8 cm at pressures up to 400 atmospheres for different base pressures of hydrogen. In the enhancement absorption profiles of the band in H2–Ne mixtures, the S(1) line at all pressures and the QP component at low pressures show doublet structures. In the enhancement contours in H2–Kr mixtures, there is an indication of the QQ component between the QP and QR maxima at higher pressures, and the O and S lines are much stronger than the corresponding lines in H2–Ne mixtures. Integrated absorption coefficients were measured for each of the mixtures studied, and the binary and ternary absorption coefficients were derived. The values of the binary coefficients are 2.37 × 10−35 cm6 s−1 for H2–Ne and 7.56 × 10−35 cm6 s−1 for H2–Kr.

INDUCED INFRARED ABSORPTION IN HYDROGEN AND HYDROGEN - FOREIGN GAS MIXTURES AT PRESSURES UP TO 1500 ATMOSPHERES

1954 ◽  
Vol 32 (4) ◽  
pp. 291-312 ◽  
Author(s):  
D. A. Chisholm ◽  
H. L. Welsh
Keyword(s):  
Kinetic Energy ◽  
Absorption Band ◽  
Absorption Coefficient ◽  
Infrared Absorption ◽  
High Frequency ◽  
Absorption Process ◽  
Rate Of Increase ◽  
Frequency Components ◽  
Relative Kinetic ◽  
Gas Pressures

The pressure-induced fundamental infrared absorption band of hydrogen has been investigated in the pure gas and in hydrogen–helium, hydrogen–nitrogen, and hydrogen–argon mixtures for gas pressures up to 1500 atm. and temperatures in the range 80°–376°K. At the higher densities the rate of increase of the integrated absorption coefficient with density is anomalously large; this effect is interpreted in terms of finite molecular volumes. The Q branch has been shown to consist of three components QP, Qq, and QR. The separation of the maxima in the low- and high-frequency components, QP and QR, depends on the perturbing gas and increases linearly with its density; the separation and relative intensities of the components are also strongly dependent on the temperature. It is proposed that this splitting of the Q branch is caused by the participation of the relative kinetic energy of the colliding molecules in the absorption process for collisions in the region of overlap forces. The Qq component and the S lines show no splitting and are probably produced by collisions in the region of quadrupole interaction.

THEORY OF TRANSLATIONAL ABSORPTION IN GASES

1961 ◽  
Vol 39 (1) ◽  
pp. 189-204 ◽  
Author(s):  
J. D. Poll ◽  
J. Van Kranendonk
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Dipole Moments ◽  
Gas Mixtures ◽  
Absorption Coefficients ◽  
Monatomic Gas

The theory of translational infrared absorption in gases is developed. Invariant expressions for the integrated absorption coefficients are derived. The absorption coefficients are expanded in powers of the density, and the binary absorption coefficients are expressed in terms of a model for the induced pair dipole moments. Monatomic gas mixtures, diatomic gases, and diatomic–monatomic gas mixtures are considered in detail. As an application the binary absorption coefficient of the translational band of hydrogen is calculated.

PRESSURE-INDUCED INFRARED ABSORPTION OF HYDROGEN AND HYDROGEN – FOREIGN GAS MIXTURES IN THE RANGE 1500–5000 ATMOSPHERES

1958 ◽  
Vol 36 (1) ◽  
pp. 88-103 ◽  
Author(s):  
W. F. J. Hare ◽  
H. L. Welsh
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Room Temperature ◽  
Pure Hydrogen ◽  
Vibrational Transition ◽  
Absorption Process ◽  
Quadrupole Interactions ◽  
Relative Kinetic ◽  
Very High ◽  
Absorption Of Hydrogen

The pressure-induced infrared absorption of hydrogen was studied in pure hydrogen and in hydrogen–helium, hydrogen–argon, and hydrogen–nitrogen mixtures at pressures up to 5000 atm. at room temperature. The integrated absorption coefficient can be expressed in the form α1ρaρp + α2ρaρp2 over the whole range of densities (ρa = density of H2, ρp = density of the perturbing gas, [Formula: see text] in the mixture experiments). The coefficient α2 is much smaller than predicted from the effect of finite molecular volumes; this is interpreted as a partial cancellation of the induced moments in ternary collisions. The splitting of the Q branch of the fundamental, which is due to the participation of the relative kinetic energies of the colliding molecules in the absorption process, increases linearly with the density because of ternary collisions; a more rapid increase observed at very high densities is not yet explained. The components of the overtone and double vibrational transition, like the QQ and S components of the fundamental, show no splitting or broadening with increasing density; these absorptions are believed to be due to quadrupole interactions while the QP and QR components of the fundamental are due to overlap interactions.

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