Vibrational modes and resonant Raman spectra of new B2C nanoribbons

2011 ◽  
Vol 375 (28-29) ◽  
pp. 2733-2737
Author(s):  
Xiaowei Li ◽  
Yuehua Xu ◽  
Jinming Dong
Keyword(s):  
Raman Spectra ◽  
Vibrational Modes ◽  
Resonant Raman

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.

Resonant Raman spectra of molecules with diradical character: multiconfigurational wavefunction investigation of neutral viologens

2014 ◽  
Vol 16 (39) ◽  
pp. 21721-21731 ◽  
Author(s):  
Julia Romanova ◽  
Vincent Liégeois ◽  
Benoît Champagne
Keyword(s):  
Raman Spectra ◽  
Resonance Raman ◽  
Diradical Character ◽  
Multiconfigurational Methods ◽  
Resonant Raman

In search for a relationship between the diradical character and resonance Raman signatures of neutral viologens by multiconfigurational methods.

Photoluminescence and resonant Raman spectra of silicon films produced by size-selected cluster beam deposition

1997 ◽  
Vol 56 (11) ◽  
pp. 6958-6964 ◽  
Author(s):  
M. Ehbrecht ◽  
B. Kohn ◽  
F. Huisken ◽  
M. A. Laguna ◽  
V. Paillard
Keyword(s):  
Raman Spectra ◽  
Silicon Films ◽  
Cluster Beam ◽  
Resonant Raman ◽  
Cluster Beam Deposition ◽  
Beam Deposition

Identification of Vibrational Modes in BaSi2 Epitaxial Films by Infrared and Raman Spectroscopy

2018 ◽  
Vol 386 ◽  
pp. 43-47 ◽  
Author(s):  
Hirofumi Hoshida ◽  
Naoki Murakoso ◽  
Takashi Suemasu ◽  
Yoshikazu Terai
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Epitaxial Films ◽  
Ir Absorption ◽  
Vibrational Modes ◽  
Depolarization Ratio ◽  
Phonon Line ◽  
Infrared And Raman Spectroscopy ◽  
Raman Intensities ◽  
Polarized Raman

Infrared (IR) absorption and polarized Raman spectra were measured in BaSi2 epitaxial films to investigate the vibrational modes and the symmetry of Si4 cluster in BaSi2. By an analysis based on Raman and/or IR activity in the spectra, the symmetry of Si4 cluster was determined as Th-symmetry and the observed Raman lines and IR peaks were assigned to Ag, Eg, Fg, and Fu, respectively. In the three Raman lines of Fg-mode, one LO phonon line and two TO phonon lines were classified by the depolarization ratio of polarized Raman intensities.

UV resonant Raman spectra of nitrobenzene adsorbed on Ni(111)

1996 ◽  
Vol 368 (1-3) ◽  
pp. 292-295 ◽  
Author(s):  
K. Sakamoto ◽  
H. Hashizume ◽  
M. Nagafusa ◽  
H. Sato ◽  
S. Ushioda
Keyword(s):  
Raman Spectra ◽  
Resonant Raman

Breit-Wigner-Fano Lineshape Analysis of the angential G-band of Metallic Nanotubes

2000 ◽  
Vol 633 ◽  
Author(s):  
Sandra D. Brown ◽  
Ado Jorio ◽  
Paola Corio ◽  
Mildred Dresselhaus ◽  
Gene Dresselhaus ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectra ◽  
Line Shape ◽  
Frequency Component ◽  
Lineshape Analysis ◽  
Raman Study ◽  
Resonant Raman ◽  
Band Spectra ◽  
Lorentzian Lineshape ◽  
Diameter Distributions

AbstractWe present a resonant Raman study of the tangential G-band in metallic SWNTs. By measuring the Raman spectra for isolated SWNTs, we show that the two different lineshapes observed for semiconducting and metallic SWNTs in bundles also occur for isolated SWNTs. A lineshape analysis of the tangential G-band feature for metallic SWNT bundles is presented, showing that only two components are present, the higher frequency component having a Lorentzian lineshape, and the lower one having a Breit–Wigner–Fano (BWF) line-shape. Through comparisons of the Raman tangential G-band spectra from three different diameter distributions of carbon nanotubes, we find that both the frequency and linewidth of the BWF component are diameter dependent.

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