Raman Spectra of BxNyCz - Nanotubes: Correlation between B, N - Content and Frequency Shifts of the G-band

2004 ◽  
Author(s):  
T. Skipa
Keyword(s):  
Raman Spectra ◽  
Frequency Shifts ◽  
N Content

Frequency Shifts in Raman Spectra of Liquid Crystals at the Phase Transitions

1973 ◽  
Vol 34 (3) ◽  
pp. 841-841 ◽  
Author(s):  
Hiroshi Itoh ◽  
Hiroki Nakatsuka ◽  
Masahiro Matsuoka
Keyword(s):  
Phase Transitions ◽  
Liquid Crystals ◽  
Raman Spectra ◽  
Frequency Shifts

Pressure shifts in the vibrational Raman spectra of hydrogen and deuterium, 315–85 K

1978 ◽  
Vol 56 (8) ◽  
pp. 1102-1108 ◽  
Author(s):  
E. C. Looi ◽  
J. C. Stryland ◽  
H. L. Welsh
Keyword(s):  
Standard Deviation ◽  
Raman Spectra ◽  
Rotational Level ◽  
The Other ◽  
Dispersion Forces ◽  
Temperature Dependent ◽  
Vibrational Coupling ◽  
Frequency Shifts ◽  
Linear Coefficient ◽  
Gas Density

The Raman frequencies of the Q(J) lines of the fundamental Raman bands of compressed H2 and D, were measured with a standard deviation of ±0.02 cm−1 at gas densities from 10 to 100 amagat at several temperatures in the range 315 to 85 K. The frequency shifts are negative and linear in the gas density; they range up to −1.2 cm−1 for H2 and −0.7 cm−1 for D2. The linear coefficient for the Q(J) line has the form, ai + ac(nJ/n), where nJ/n is the fractional population of the rotational level, J, and ai and ac are constants independent of J. The constant ai is strongly temperature-dependent and is interpreted as the vibrational shift due to isotropic dispersion and overlap forces. On the other hand, ac is practically temperature-independent and is believed to arise from vibrational coupling through dispersion forces.

Spectra and Structure of Silicon-Containing Compounds. X. Infrared and Raman Spectra of Methoxytrimethylsilane and Methoxy-D3-Trimethylsilane

1978 ◽  
Vol 32 (5) ◽  
pp. 457-462 ◽  
Author(s):  
J. R. Durig ◽  
B. J. Streusand
Keyword(s):  
Solid State ◽  
Internal Rotation ◽  
Raman Spectra ◽  
Strong Mixing ◽  
Isotopic Substitution ◽  
Infrared And Raman Spectra ◽  
Vibrational Assignment ◽  
Torsional Mode ◽  
Frequency Shifts ◽  
Bending Mode

The infrared (20 to 3100 cm−1) and Raman (10 to 3100 cm−1) spectra of gaseous (CH3)3SiOCH3 and (CH3)3SiOCD3 have been recorded. The Raman spectra of both liquids and the infrared and Raman spectra of the “light” compound in the solid state have also been recorded. A vibrational assignment based upon depolarization ratios, frequency shifts with isotopic substitution, and group frequencies is proposed. The Si—O torsional mode was observed at 67 cm−1 which gives a barrier to internal rotation of 1.02 kcal/mol. Strong mixing of the Si—O—C bending mode with the C—Si—C bends is proposed. The CH3—O torsion was not observed.

Polarized Raman Spectra of Carbon Nanotubes

2000 ◽  
Vol 633 ◽  
Author(s):  
Ado Jorio ◽  
Sandra D.M Brown ◽  
Gene Dresselhaus ◽  
Mildred S. Dresselhaus ◽  
Marcos A. Pimentap ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Group Theory ◽  
Raman Spectra ◽  
Theory Analysis ◽  
Frequency Shifts ◽  
Theoretical Predictions ◽  
Polarized Raman

AbstractP olarizedresonant Raman spectra for the G-band were obtained from a rope of aligned semiconducting SWNTs and from nonaligned semiconducting and metallic SWNTs. Based on group theory analysis and related theoretical predictions, we assign the symmetry for the modes in the G-band of both metallic and semiconducting SWNTs. he frequency shifts of the tangential G modes from the 2D graphite-like E2g2 frequency are discussed in terms of the nanotube geometry.

Applications of Four-Channel Raman Difference Spectroscopy

1981 ◽  
Vol 35 (4) ◽  
pp. 428-432 ◽  
Author(s):  
Jaan Laane ◽  
Wolfgang Kiefer
Keyword(s):  
Raman Spectra ◽  
Carbon Disulfide ◽  
Simultaneous Measurement ◽  
Photon Counting ◽  
High Accuracy ◽  
Difference Spectroscopy ◽  
Difference Spectra ◽  
Counting System ◽  
Frequency Shifts ◽  
Very High

A four-channel photon counting system has been constructed for the measurement of Raman difference spectra. In this work we will describe the applications and advantages of such a system. Specifically, the simultaneous measurement of the parallel and perpendicular polarized compounds of the Raman spectra of both benzene and a mixture of benzene and benzene-d6 will be discussed. Spectra of two different mixtures of benzene and carbon disulfide and of the pure components were also recorded simultaneously using the four separate channels of the photon counting system. For both sets of data the solvent-induced frequency shifts were determined with very high accuracy.

The crystal structure of RbCdCl3 and the polarized Raman spectra of RbCdX3 (X = Cl, Br)

1978 ◽  
Vol 56 (9) ◽  
pp. 1192-1195 ◽  
Author(s):  
Mahadevan Natarajan ◽  
Helen Elaine Howard-Lock ◽  
Ian David Brown
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
X Ray Diffraction ◽  
Frequency Shifts ◽  
X Ray ◽  
Polarized Raman

The polarized Raman spectra of single crystals of RbCdCI3 and RbCdBr3 (isostructural with NH4CdCl3) have been measured and analysed by comparison of the frequency shifts. The crystal structure of RbCdCl3 refined by X-ray diffraction is also reported.

Infrared and Raman Spectra of Pyrazinium Halides

1970 ◽  
Vol 24 (6) ◽  
pp. 601-605 ◽  
Author(s):  
R. Foglizzo ◽  
A. Novak
Keyword(s):  
Raman Spectra ◽  
Ir And Raman Spectra ◽  
Infrared And Raman Spectra ◽  
Frequency Shifts ◽  
Ir And Raman

The ir and Raman spectra of pyrazinium chloride and bromide and their ND deuterated derivatives have been obtained in the 4000–300 cm−1 range. Twenty-six fundamentals of the pyrazinium ion are identified and compared to those of the pyrazine molecule. Frequency shifts on protonation of pyrazine are discussed.

Raman and magnetization studies of barium ferrite powder prepared by water-in-oil microemulsion

2000 ◽  
Vol 15 (2) ◽  
pp. 483-487 ◽  
Author(s):  
M. S. Chen ◽  
Z. X. Shen ◽  
X. Y. Liu ◽  
J. Wang
Keyword(s):  
Magnetic Properties ◽  
Calcination Temperature ◽  
Raman Spectra ◽  
Ferrite Powder ◽  
X Ray Diffraction ◽  
Ferric Ions ◽  
Frequency Shifts ◽  
X Ray ◽  
Calcination Temperatures ◽  
Crystallization Effect

Micro-Raman spectroscopy was used to study the formation of BaFe12O19 (BaM) powders derived from water-in-oil microemulsion at different calcination temperatures. With increase in the calcination temperature, the Raman spectra of the BaM powders become narrower and stronger without apparent frequency shifts of the Raman bands. The calcination temperature dependence of the Raman spectra and the magnetic properties of the BaM powders result from the crystallization rather than size effect. Our results show that there is a strong correlation between the crystallinity and the magnetic properties, which could be explained in terms of the crystallization effect on the superexchange interaction between ferric ions. The γ–Fe2O3 phase occurred in the BaM precursor and the powder calcined at 500 °C. The α–Fe2O3 phase was developed in the powders calcined at 500, 600, and 700 °C, which was not detected by x-ray diffraction. With increasing calcination temperature, the γ–Fe2O3 phase can either react with oxide containing barium to form the BaM phase or transform to the α–Fe2O3 phase. The amount of α–Fe2O3 decreases due to reaction with BaCO3 to form BaM phase at higher calcination temperature.

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