Fe2+ Electronic Transitions in Raman and Infrared Spectra of FePSe3 and FePS3 Crystals

1988 ◽  
Vol 135 ◽  
Author(s):  
M. Jouanne ◽  
M.L. Sanjuan ◽  
M.A. Kanehisa ◽  
M. Balkanski ◽  
P. Cavalli ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Electronic Transitions ◽  
Tentative Model ◽  
Polarized Raman ◽  
Absorption Measurements

AbstractPolarized Raman scattering and infrared absorption measurements were carried out in FePS3 and FePSe3 as a function of temperature. Features at 700-2000 cm−1 are shown to be essentially due to transitions among the trigonal-field-split 5T2g multiplet of the Fe2+ iron and their phonon sidebands. Though the unpolarized Raman spectra are similar in both compounds, polarized spectra are markedly different. We propose a tentative model to account for this.

Theoretical study of the ν3 and ν4 Raman bands of methane in rare gas matrices

1976 ◽  
Vol 54 (13) ◽  
pp. 2154-2161 ◽  
Author(s):  
Koji Kobashi ◽  
Yosuke Kataoka ◽  
Tsunenobu Yamamoto
Keyword(s):  
Raman Scattering ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Low Temperatures ◽  
Theoretical Study ◽  
Mutual Exclusion ◽  
Theoretical Work ◽  
Rare Gas ◽  
Vibration Rotation

Theoretical study has been carried out on the Raman spectra of the ν3 and ν4 vibration bands of methane in Ar, Kr, and Xe matrices at low temperatures. The present study is a continuation of a theoretical work by Nishiyama and Yamamoto on the infrared spectra of the same Systems. We consider the symmetry of the System under the group [Formula: see text] introducing the inversion functions to generalize Wigner's rotational functions. As a result, dual assignments are given to each vibration–rotation state. The allowed transitions of the Raman scattering are compared with those of the infrared absorption, and it is found that a kind of 'rule of mutual exclusion' holds. The relative intensities and spacings of the Raman spectra are calculated and successfully compared with experiment.

Infrared absorption and resonance Raman scattering of photochromic triphenylformazans

1983 ◽  
Vol 61 (5) ◽  
pp. 809-816 ◽  
Author(s):  
J. W. Lewis ◽  
C. Sandorfy
Keyword(s):  
Excited State ◽  
Raman Scattering ◽  
Proton Transfer ◽  
Raman Spectra ◽  
Infrared Absorption ◽  
Resonance Raman ◽  
Tautomeric Equilibrium ◽  
Resonance Raman Scattering ◽  
Excited State Proton Transfer ◽  
Resonance Raman Spectra

The infrared and resonance Raman spectra of the two long-lived forms of triphenylformazan and several of its derivatives have been examined. The spectra of unsymmetrically 15N-labelled derivatives suggest that two tautomers exist for each of the two forms. This observation is confirmed by the spectra of 1-(p-halophenyl)-3,5-diphenylformazans. The spectra of the non-chelate forms of these latter compounds demonstrate that the position of the tautomeric equilibrium is influenced by the electron-attracting ability of the para-halo-substituent. A comparison of the resonance Raman spectra of the two forms leads to the conclusion that excited state proton transfer is the initial photoevent in the photochromism of the triphenylformazans.

Polarized Raman Scattering Study of ZnGeP2 Single Crystals

1997 ◽  
Vol 484 ◽  
Author(s):  
Spirit Tlali ◽  
Howard E. Jackson ◽  
M. C. Ohmer ◽  
P. G. Schunemann ◽  
T. M. Pollak
Keyword(s):  
Raman Scattering ◽  
Single Crystals ◽  
Raman Spectra ◽  
Low Temperatures ◽  
High Quality ◽  
Crystal Orientations ◽  
Gradient Technique ◽  
Theoretical Predictions ◽  
Scattering Study ◽  
Polarized Raman

AbstractRaman scattering experiments on high quality ZnGeP2 single crystals grown by the seeded horizontal dynamic gradient technique have been carried out. Polarized Raman spectra were obtained in the backscattering geometry at both room and low temperatures for several crystal orientations and compared with group theoretical predictions. Raman spectra from as-grown and annealed samples display distinctive differences which were explored by utilizing two different excitation wavelengths: 514.3 nm and 632.8 nm; the observed differences are attributed to a surface interdiffuasion effect.

Infrared Spectra and Structures of Solid CH4 and CD4 in Phases I and II

1972 ◽  
Vol 50 (21) ◽  
pp. 3521-3533 ◽  
Author(s):  
C. Chapados ◽  
A. Cabana
Keyword(s):  
Phase I ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Noble Gas ◽  
Rotational Diffusion ◽  
Local Symmetry ◽  
Higher Temperature ◽  
Solid Phases ◽  
Angular Oscillations ◽  
Absorption Measurements

This paper reports the results of extensive infrared absorption measurements of CH4, CD4, and mixed isotopic crystals containing CH4, CD4, CHD3, and CH3D at low concentration in matrices of light and heavy methane in crystalline phases I and II. The interpretation of the spectra, based upon the Halford–Hornig approach, provides information on the crystal structures. The spectra indicate that the two solid phases of CH4 are similar to the two higher temperature phases of CD4. In phase I, there is apparently considerable motion: either the molecules undergo large angular oscillations or even rotational diffusion. In phase II, there exist two types of sites for the molecules: some molecules undergo quantized rotation similar to that found in noble gas matrices while others order with a local symmetry that is probably slightly distorted from Td[Formula: see text] to D2d[Formula: see text]. Acceptable factor groups are then limited to Td and Oh, but the former is unlikely for it could yield the f.c.c. lattice found by diffraction experiments only by a particular choice of the parameters, whereas the latter leads to the f.c.c. space group [Formula: see text] (Fm 3c).

Vibrational Raman Scattering from high TC single Crystals

1987 ◽  
Vol 99 ◽  
Author(s):  
D. M. Krol ◽  
M. Stavola ◽  
L. F. Schneemeyer ◽  
J. V. Waszczak ◽  
W. Weber
Keyword(s):  
Chemical Composition ◽  
Raman Scattering ◽  
Single Crystals ◽  
Raman Spectra ◽  
Peak Position ◽  
High Tc ◽  
Stretching Vibration ◽  
Polarized Raman ◽  
Axial Stretching

ABSTRACTPolarized Raman spectra have been measured on single crystals of the high Tc materials A2BCu3Ox with A=Ba and Sr, B=Y and La and 6<x<7. The dependence of the 500 cm-i peak position (αzz)on chemical composition is in agreement with its assignment to the O(1) axial stretching vibration. The intensity of the 600 cm1 band, which has been ascribed to a defect induced Cu-O mode, strongly depends on the crystal preparation and resulting purity.

ORTHO AND PARA STATES OF INTERSTITIAL H2 IN SILICON AND GALLIUM ARSENIDE

2004 ◽  
Vol 18 (11) ◽  
pp. 453-466 ◽  
Author(s):  
E. V. LAVROV
Keyword(s):  
Gallium Arsenide ◽  
Raman Scattering ◽  
Band Gap ◽  
Raman Spectra ◽  
Spin State ◽  
Infrared Absorption ◽  
Nuclear Spin ◽  
Hydrogen Molecule ◽  
Room Temperature ◽  
Absorption Studies

A survey of recent Raman scattering studies on the interstitial hydrogen molecule ( H 2) in Si and GaAs is presented. It is shown that properties of H 2 strongly depend on the nuclear spin state I. In either material, para- H 2 (I=0) is unstable against irradiation with band gap light. In the case of Si, para- H 2 also preferentially disappears from the Raman spectra in the course of storage at room temperature in the dark. Possible explanations for this surprising behavior are discussed and compared with the latest infrared absorption studies.

scholarly journals RESONANT RAMAN SCATTERING OF INTERACTING TWO-CHANNEL QUANTUM WIRES

2001 ◽  
Vol 15 (22) ◽  
pp. 3031-3038
Author(s):  
HYUN C. LEE
Keyword(s):  
Raman Scattering ◽  
Raman Spectra ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Single Channel ◽  
Resonant Peak ◽  
Near Resonance ◽  
Resonant Raman ◽  
Resonant Raman Scattering ◽  
Polarized Raman

Resonant Raman scattering of degenerate interacting two-channel quantum wire is studied. All collective excitations of two-channel quantum wire are shown to give rise to peaks in the polarized Raman spectra near resonance. If there exist certain symmetries among interactions, a resonant peak can also appear in the depolarized Raman spectra, in contrast to the single-channel case studied by Sassetti and Kramer. We also calculate the explicit form of the scattering cross-section away from the peaks. The above features may be experimentally verified in armchair carbon nanotube systems.

Vibrational spectra of cyclopentadienyltrimethylplatinum(IV)

1971 ◽  
Vol 24 (5) ◽  
pp. 911 ◽  
Author(s):  
JR Hall ◽  
BE Smith
Keyword(s):  
Solid State ◽  
Spectral Data ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Local Symmetry ◽  
Stretching Vibrations ◽  
Polarized Raman

The Raman spectra of cyclopentadienyltrimethylplatinum(IV) in the solid state and solution have been recorded and interpreted in conjunction with the corresponding infrared spectra over the range 4000-30 cm-1. Assignments have been made on the basis of local symmetry. Polarized Raman lines at 561 and 263 cm-1 have been assigned to symmetric Pt-CH3 stretching and Pt-cp stretching vibrations respectively. The spectral data are consistent with a pentahapto π-bonded cp ring.

Electronic Raman Spectra. VII. Raman Spectra of the Lanthanides

1971 ◽  
Vol 49 (13) ◽  
pp. 2336-2344 ◽  
Author(s):  
J. A. Koningstein ◽  
P. Grunberg
Keyword(s):  
Experimental Data ◽  
Rare Earth ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Rare Earth Ions ◽  
Lanthanide Ions ◽  
Electronic Transitions ◽  
Raman Transition ◽  
Trivalent Lanthanides ◽  
Electronic Raman Scattering

Additional experimental data are reported on electronic Raman scattering of trivalent lanthanides, making the observation of this effect of the series nearly complete. The bulk of the information now available points to the fact that the intensity of electronic Raman transition is strongest for the rare earth ions in the middle of the series. The most profound differences of polarization features of electronic transitions and phonons is observed in the situation where the lanthanide ions have an odd number of 4f electrons. Antisymmetric scattering tensors play a less important role.

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