Calculated phonon modes, infrared, and Raman spectra in ZnGeGa2N4

2020 ◽  
Vol 128 (7) ◽  
pp. 075702
Author(s):  
Amol Ratnaparkhe ◽  
Walter R. L. Lambrecht
Keyword(s):  
Raman Spectra ◽  
Infrared And Raman Spectra ◽  
Phonon Modes

scholarly journals Calculated phonon modes, infrared and Raman spectra in orthorhombic α − MoO3 and monolayer MoO3

2021 ◽  
Vol 130 (10) ◽  
pp. 104302
Author(s):  
Amol Ratnaparkhe ◽  
Santosh Kumar Radha ◽  
Walter R. L. Lambrecht
Keyword(s):  
Raman Spectra ◽  
Infrared And Raman Spectra ◽  
Phonon Modes

Vibration spectra of sulphur tetranitride

1981 ◽  
Vol 46 (11) ◽  
pp. 2613-2619 ◽  
Author(s):  
Jiří Toužín
Keyword(s):  
Solid State ◽  
Raman Spectra ◽  
Normal Coordinate Analysis ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Vibration Spectra

Available data on infrared and Raman spectra of S4N4 in solid state and solutions have been verified and completed. On the basis of normal coordinate analysis an attempt has been made to define with more precision the interpretation of vibration spectra of this compound given in earlier reports.

Vibrational spectra of aquadioxotetra; peroxodivanadates(V) M2[V2O2(O2)4(H2O)]·xH2O (M = N(CH3)4, Cs)

1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Infrared And Raman Spectra ◽  
Empirical Correlations ◽  
Normal Coordinate ◽  
Bond Lengths ◽  
Stretching Vibrations

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.

Infrared and Raman Spectra, conformations,ab initio calculations and spectral assignments of 1,3-disilabutane (SiH3CH2SiH2CH3)

2007 ◽  
Vol 38 (9) ◽  
pp. 1159-1173 ◽  
Author(s):  
Gamil A. Guirgis ◽  
Paul M. Mazzone ◽  
Daniel N. Pasko ◽  
Peter Klaeboe ◽  
Anne Horn ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Raman Spectra ◽  
Infrared And Raman Spectra

scholarly journals Phonons in Short-Period GaN/AlN Superlattices: Group-Theoretical Analysis, Ab initio Calculations, and Raman Spectra

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 286
Author(s):  
Valery Davydov ◽  
Evgenii Roginskii ◽  
Yuri Kitaev ◽  
Alexander Smirnov ◽  
Ilya Eliseyev ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Raman Spectra ◽  
Density Functional ◽  
Structural Characteristics ◽  
Vibrational Modes ◽  
Phonon Modes ◽  
Short Period ◽  
Group Theoretical Analysis

We report the results of experimental and theoretical studies of phonon modes in GaN/AlN superlattices (SLs) with a period of several atomic layers, grown by submonolayer digital plasma-assisted molecular-beam epitaxy, which have a great potential for use in quantum and stress engineering. Using detailed group-theoretical analysis, the genesis of the SL vibrational modes from the modes of bulk AlN and GaN crystals is established. Ab initio calculations in the framework of the density functional theory, aimed at studying the phonon states, are performed for SLs with both equal and unequal layer thicknesses. The frequencies of the vibrational modes are calculated, and atomic displacement patterns are obtained. Raman spectra are calculated and compared with the experimental ones. The results of the ab initio calculations are in good agreement with the experimental Raman spectra and the results of the group-theoretical analysis. As a result of comprehensive studies, the correlations between the parameters of acoustic and optical phonons and the structure of SLs are obtained. This opens up new possibilities for the analysis of the structural characteristics of short-period GaN/AlN SLs using Raman spectroscopy. The results obtained can be used to optimize the growth technologies aimed to form structurally perfect short-period GaN/AlN SLs.

scholarly journals Resonance and antiresonance in Raman scattering in GaSe and InSe crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Osiekowicz ◽  
D. Staszczuk ◽  
K. Olkowska-Pucko ◽  
Ł. Kipczak ◽  
M. Grzeszczyk ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Temperature Effect ◽  
Band Gap ◽  
Raman Spectra ◽  
Quantum Interference ◽  
Optical Band Gap ◽  
Phonon Coupling ◽  
Phonon Modes ◽  
Electron Phonon Coupling ◽  
Resonant Raman

AbstractThe temperature effect on the Raman scattering efficiency is investigated in $$\varepsilon$$ ε -GaSe and $$\gamma$$ γ -InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.

CONFORMATIONAL EQUILIBRIA IN OPEN-CHAIN α,β-UNSATURATED KETONES

1961 ◽  
Vol 39 (11) ◽  
pp. 2225-2235 ◽  
Author(s):  
K. Noack ◽  
R. Norman Jones
Keyword(s):  
Raman Spectra ◽  
Equilibrium Mixture ◽  
Infrared And Raman Spectra ◽  
Temperature Dependent ◽  
Trans Form ◽  
Open Chain ◽  
Unsaturated Ketones ◽  
Conformational Isomers ◽  
Alkyl Substitution ◽  
Conformational Equilibria

The infrared and Raman spectra of trans-Δ3-penten-2-one have been measured over the temperature range +30° to −75° and +85° to +5° respectively. The temperature-dependent changes observed in the spectra indicate that this ketone exists as an equilibrium mixture of s-cis and s-trans conformational isomers in the liquid state. The s-trans form is the more stable and is present exclusively in the crystalline solid.Similar measurements have been carried out on Δ3-buten-2-one. The infrared and Raman spectra of this ketone also exhibit temperature effects that can be explained by a similar equilibrium, though the evidence is not as conclusive as for trans-Δ3-penten-2-one.The influence of alkyl substitution at the α- and β-carbon atoms on the relative stability of the s-cis and s-trans forms of α,β-unsaturated ketones is discussed.

Infrared and Raman spectra, vibrational assignment, and ab initio calculations of fluoromalononitrile

1997 ◽  
Vol 53 (12) ◽  
pp. 2001-2012 ◽  
Author(s):  
M. Dakkouri ◽  
A. Grunvogel-Hurst ◽  
Gamil A. Guirgis ◽  
Zhenhong Yu ◽  
Yanping Jin ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Raman Spectra ◽  
Infrared And Raman Spectra ◽  
Vibrational Assignment
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