scholarly journals Shedding light onto the spectra of lime—Part 2: Raman spectra of Ca and Mg carbonates and the role of d ‐block element luminescence

2021 ◽  
Author(s):  
Thomas Schmid ◽  
Ronja Kraft ◽  
Petra Dariz
Keyword(s):  
Raman Spectra ◽  
Block Element

scholarly journals Graphene Domain Signature of Raman Spectra of sp2 Amorphous Carbons

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2021
Author(s):  
Elena F. Sheka ◽  
Yevgeny A. Golubev ◽  
Nadezhda A. Popova
Keyword(s):  
Raman Spectra ◽  
Molecular Spectroscopy ◽  
Basic Structure ◽  
Quasi Particle ◽  
Phonon Spectra ◽  
2D Pattern ◽  
Density Delocalization ◽  
Electron Density Delocalization ◽  
High Degree

The standard D-G-2D pattern of Raman spectra of sp2 amorphous carbons is considered from the viewpoint of graphene domains presenting their basic structure units (BSUs) in terms of molecular spectroscopy. The molecular approximation allows connecting the characteristic D-G doublet spectra image of one-phonon spectra with a considerable dispersion of the C=C bond lengths within graphene domains, governed by size, heteroatom necklace of BSUs as well as BSUs packing. The interpretation of 2D two-phonon spectra reveals a particular role of electrical anharmonicity in the spectra formation and attributes this effect to a high degree of the electron density delocalization in graphene domains. A size-stimulated transition from molecular to quasi-particle phonon consideration of Raman spectra was experimentally traced, which allowed evaluation of a free path of optical phonons in graphene crystal.

Critical Role of Tricyclic Bridges Including Neighboring Rings for Understanding Raman Spectra of Zeolites

2019 ◽  
Vol 141 (51) ◽  
pp. 20318-20324 ◽  
Author(s):  
Tongkun Wang ◽  
Song Luo ◽  
Geoffrey A. Tompsett ◽  
Michael T. Timko ◽  
Wei Fan ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Critical Role

The Role of Fermi and Darling–Dennison Resonances in the Formation of the Raman Spectra of Water and Water–Ethanol Solutions

2019 ◽  
Vol 83 (3) ◽  
pp. 324-329 ◽  
Author(s):  
I. V. Plastinin ◽  
S. A. Burikov ◽  
S. A. Dolenko ◽  
T. A. Dolenko
Keyword(s):  
Raman Spectra

Interface Effects on the Raman Spectra of Si/3C-SiC Superlattices

2000 ◽  
Vol 640 ◽  
Author(s):  
E. F. Bezerra ◽  
A. G. Souza Filho ◽  
J. Mendes Filho ◽  
V. Lemos ◽  
V. N. Freire ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Theoretical Calculations ◽  
Linear Chain ◽  
Dispersion Relations ◽  
Chain Model ◽  
Virtual Crystal Approximation ◽  
Smooth Interface ◽  
Bond Polarizability ◽  
Interface Effects

ABSTRACTTheoretical calculations are performed on the role of smooth interfaces in the Raman spectra of Si/3C-SiC superlattices. The dispersion relations were obtained using a linear chain model with the alloyed interface δ-(3C-SiC)0.5(Si)0.5 described in the virtual crystal approximation. A modified bond-polarizability model was used to calculate the Raman spectra. The main results are the enhancement of the Raman spectra and the appearance of new peaks in between those related to the Si quasi confined and the 3C-SiC-confined modes with increasing number δ?of interfacial monolayers (3C-SiC)0.5(Si)0.5. Some of the smooth interface related Raman peaks have intensity comparable with those of an abrupt Si/3C-SiC superlattice.

Role of intramolecular interactions in Raman spectra of N2 and O2 molecules

2003 ◽  
Vol 217 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M.A. Buldakov ◽  
V.N. Cherepanov ◽  
B.V. Korolev ◽  
I.I. Matrosov
Keyword(s):  
Raman Spectra ◽  
Intramolecular Interactions

scholarly journals Role of electronic excitations in magneto-Raman spectra of graphene

2012 ◽  
Vol 14 (10) ◽  
pp. 105016 ◽  
Author(s):  
Oleksiy Kashuba ◽  
Vladimir I Fal'ko
Keyword(s):  
Raman Spectra ◽  
Electronic Excitations

Role of intramolecular interactions in Raman spectra of N 2 and O 2 molecules

2002 ◽  
Author(s):  
Michail A. Buldakov ◽  
Victor N. Cherepanov ◽  
Boris V. Korolev ◽  
Ivan I. Matrosov
Keyword(s):  
Raman Spectra ◽  
Intramolecular Interactions

ELASTOOPTICAL SPECTRA OF NOVEL L-LYSINE MONOHYDROCHLORIDE DEHYDRATE SINGLE CRYSTALS

2010 ◽  
Vol 24 (05) ◽  
pp. 629-645 ◽  
Author(s):  
V. KRISHNAKUMAR ◽  
R. NAGALAKSHMI ◽  
S. MANOHAR ◽  
K. OZGA ◽  
B. CLAUDET ◽  
...  
Keyword(s):  
Single Crystals ◽  
Raman Spectra ◽  
Xrd Analysis ◽  
Principal Role ◽  
Space Group ◽  
Ft Raman

We have established highly anisotropic features of the piezooptical coefficient behavior in L-lysine monohydrochloride dihydrate (LLMHCl) single crystals (a semiorganic material with space group P2 1). These coefficients show substantial anisotropy for the diagonal and off-diagonal tensor coefficients. The XRD analysis, FTIR, optical and FT Raman spectra were performed. Following the obtained data, principal role of the phonon sub-system was established.

scholarly journals Raman spectroscopic study of bioactive silica-based glasses: The role of the alkali/alkali earth ratio on the Non-Bridging Oxygen/Bridging Oxygen (NBO/BO) ratio

2009 ◽  
Vol 23 (3-4) ◽  
pp. 227-232 ◽  
Author(s):  
Lucia Marsich ◽  
Loredana Moimas ◽  
Valter Sergo ◽  
Chiara Schmid
Keyword(s):  
Raman Spectra ◽  
Glass Composition ◽  
Linear Increase ◽  
Calibration Plot ◽  
Bioactive Glasses ◽  
Raman Spectroscopic ◽  
Alkali Earth ◽  
Raman Spectroscopic Study ◽  
Dissolution Tests

Raman spectra of bioactive glasses of the Na2O–K2O–MgO–CaO–B2O3–P2O5–SiO2to be used in bone reconstruction systems have been collected from samples with three different concentrations of alkali and alkali earth elements. Compositions were chosen with a constant total amount of modifiers and formers, with only minor changes among the formers. The ratio of Non-Bridging Oxygens to Bridging Oxygens (NBO/BO) has been obtained from the Raman spectra and reported as a function of the alkali/alkali earth ratio, showing a linear increase. Dissolution tests indicate also a linear dependence of the amount of Na+, K+and Ca++ions leached in water on the alkali/alkali earth ratio. Consequently a calibration plot correlating the NBO/BO ratio with the amount of Na+, K+and Ca++ions leached in water has been obtained, thus demonstrating the sensitivity of the method, given that the changes from one glass composition to the other are of the order of some points in percentage among the glass modifiers.

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