X-ray Raman scattering on polycrystalline graphite in the scattering angle range 0–120°

1983 ◽  
Vol 61 (4) ◽  
pp. 629-632 ◽  
Author(s):  
Z. I. Kavogli ◽  
D. K. Leventouri ◽  
C. N. Koumelis
Keyword(s):  
Raman Spectrum ◽  
Raman Scattering ◽  
Raman Line ◽  
Scattering Angle ◽  
X Ray ◽  
Peak Intensity ◽  
Polycrystalline Graphite

X-ray Raman scattering was studied on polycrystalline graphite for various scattering angles in the range 0–120°. A mosaic graphite spectrometer without collimators and Crkβ radiation were used.The shape of the Raman spectrum depended slightly on the scattering angle. The peak intensity of the Raman line increases with scattering angle but in a different way to that resulting from the calculation of Mizuno and Ohmura. Additional components were observed in the spectrum on both sides of the Raman line.

scholarly journals Influence of the Crystal Texture on Raman Spectroscopy of the AlN Films Prepared by Pulse Laser Deposition

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jingjing Wang ◽  
Da Chen ◽  
Yan Xu ◽  
Qixin Liu ◽  
Luyin Zhang
Keyword(s):  
Raman Spectrum ◽  
Raman Scattering ◽  
Pulse Laser Deposition ◽  
Pulse Laser ◽  
Laser Deposition ◽  
High Mode ◽  
Crystal Quality ◽  
X Ray ◽  
Crystal Texture ◽  
Xrd Patterns

We investigate the Raman scattering of the AlN films prepared by pulse laser deposition. The Raman spectrum and the X-ray diffraction (XRD) patterns of the AlN films were compared to find out the influence of the crystal texture on the Raman scattering. TheE2(high) andA1(TO) scattering modes were observed in Raman spectra. The results show that the orientation and the crystal quality of the AlN films have a great impact on these Raman scattering modes. The deterioration of (002) orientation and the appearance of other orientations in the XRD patterns lead to the weakening of theE2(high) mode and strengthening of theA1(TO) mode in the Raman spectrum. In addition, theE2(high) peak is broadened with the increasing of the width of the X-ray rocking curve. The broadening of the Raman peaks can be associated with degeneration in crystal quality. Furthermore, by combining the energy shift ofE2(high) mode with the measured residual stress in the films, the Raman-stress factor of the AlN films prepared by pulse laser deposition is −4.45 cm−1/GPa for theE2(high) mode.

scholarly journals The theory of the vibrations and the Raman spectrum of the diamond lattice

1948 ◽  
Vol 241 (829) ◽  
pp. 105-145 ◽  
Keyword(s):  
Raman Spectrum ◽  
Vibrational Spectrum ◽  
Frequency Shift ◽  
Raman Line ◽  
Elastic Constants ◽  
Lattice Dynamics ◽  
Ultra Violet ◽  
Force Constants ◽  
X Ray ◽  
Infra Red

The crystal structure of diamond was first determined by Bragg in 1913 from X-ray photographs; the carbon atoms are arranged at the apices and median points of interlinked tetrahedra. Born (1914) derived expressions for the three elastic constants of diamond in terms of two force constants related to the valency bonds between neighbouring atoms. But, at that time, the only experimental data available were the compressibility and the Debye characteristic temperature 0, and precise determination of the valence force constants was not possible. Meanwhile, investigation of the optical properties of diamond had produced evidence for the existence of two distinct types, one with an absorption band at 8 [i in the infra-red, the other transparent at this point. Robertson, Fox & Martin (1934) took up this problem and found that absorption in the infra-red is associated with absorption in the ultra-violet; diamonds transparent at 8y transmit much farther into the ultra-violet. Both types of diamond have Bragg’s tetrahedral structure, the same refractive index, specific gravity, dielectric constant and electron diffraction. Their infra-red spectra are identical up to 7y, and the frequency shift of the principal Raman line is the same. The derivation of the elastic constants was again considered by Nagendra Nath (1934). He extended the theory to include central forces between second neighbours in the lattice. He also suggested that the frequency shift of the principal Raman line corresponds to the relative vibration of the two carbon atoms in the unit cell, along the line joining their nuclei. Raman and his collaborators have recently (1941) put forward a new theory of lattice dynamics according to which the vibrational spectrum of a crystal consists of a few discrete lines. This is in direct contradiction to the quasi-continuous vibrational spectrum predicted by classical or quantum mechanics. On this new theory there are eight fundamental frequencies of vibration for diamond; the values of these frequencies are deduced from the observed specific heat, ultra-violet absorption and Raman spectrum, which, it is claimed, cannot be explained by ‘orthodox’ lattice dynamics. Raman (1944) has suggested that there are, not two, but four types of diamond, two with tetrahedral symmetry and two with octahedral symmetry depending on the electronic configurations, but X-ray analysis gives no indication of this and the attempts of his school to explain the observed infra-red spectra on the basis of their new lattice theory have been, up to now, unsuccessful.

X-ray Raman scattering in colloidal and polycrystalline graphite

1980 ◽  
Vol 58 (10) ◽  
pp. 1507-1509 ◽  
Author(s):  
C. N. Koumelis ◽  
C. A. Londos
Keyword(s):  
Raman Scattering ◽  
Short Range ◽  
Raman Band ◽  
Energy Shift ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Polycrystalline Graphite ◽  
Low Energies ◽  
The Difference ◽  
Additional Anomaly

Raman scattering was measured in colloidal and polycrystalline graphite for a scattering angle 45°, using X-ray CrKβ radiation and a mosaic graphite analysing crystal spectrometer without collimators. The use of such a spectrometer was necessary because of the weakness of the Raman effect.For the colloidal graphite, an energy shift of ΔE = 288.3 ± 0.6 eV from the primary line was observed. For the polycrystalline graphite, the above shift was ΔE = 284.9 ± 0.5 eV. These shifts can be ascribed to the transition of the 1s electrons onto and above the Fermi level, constituting the so-called Raman band.In the polycrystalline graphite, an additional anomaly was observed in the spectrum, beyond the Raman band towards the low energies, i.e., in 311 eV. This fine structure is a verification of the Weaire–Thorp concept about the difference in the spectra, due to the short-range and long-range order.

X-Ray Raman scattering in amorphous boron

1978 ◽  
Vol 56 (4) ◽  
pp. 438-439 ◽  
Author(s):  
D. K. Leventouri ◽  
S. S. Vaiopoulos ◽  
A. B. Vassilikou ◽  
C. N. Koumelis
Keyword(s):  
Raman Scattering ◽  
Raman Band ◽  
The Other ◽  
Amorphous Boron ◽  
Scattering Angle ◽  
X Ray ◽  
New Type

Raman scattering was measured using X-ray CrKβ radiation in amorphous boron for a scattering angle 45° and with a new type graphite spectrometer without collimators.Two energy shifts from the primary line were observed, one at a distance of 193 eV, which is ascribed to the Raman band, and the other at a distance of 183 eV, which is ascribed to the 1s–2p transition.

Raman scattering from impurities in nonmetals. II. Anharmonic effects

1979 ◽  
Vol 57 (1) ◽  
pp. 11-22
Author(s):  
H. C. Chow
Keyword(s):  
Raman Spectrum ◽  
Raman Scattering ◽  
Raman Line ◽  
Life Time ◽  
Resonant Scattering ◽  
Time Effect ◽  
Dipole Radiation ◽  
Anharmonic Effects ◽  
Spectrum Function

Anharmonic effects on the impurity Raman spectrum are examined on the basis of an approximately derived, nonphenomenological Raman spectrum function. It is shown that owing to the phonon life-time effect, anharmonicity broadens the zero-phonon Raman line and the accompanied satellite phonon Raman lines. The case of resonant scattering is re-examined and the result suggests that the dipole radiation formulation of Raman scattering, which is the basis of the present and some other treatments, is unsuited for demonstrating hot luminescence.

X-ray diffraction and Raman scattering studies of FeCl3–SbCl5-graphite bi-intercalation compounds

1996 ◽  
Vol 11 (12) ◽  
pp. 3039-3044 ◽  
Author(s):  
Takeshi Abe ◽  
Yasukazu Yokota ◽  
Yasuo Mizutani ◽  
Mitsuru Asano ◽  
Toshio Harada ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Raman Scattering ◽  
Intercalation Compound ◽  
Stacking Sequence ◽  
Graphite Intercalation Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphite Intercalation ◽  
Two Peaks

X-ray diffraction (XRD) and Raman spectroscopy have been used for the study of the bi-intercalation of SbCl5 into a stage 5 FeCl3-graphite intercalation compound (GIC). The stage 5 FeCl3-GIC is prepared by an ordinary two-bulb method with the temperature of graphite at 788 K and that of FeCl3 at 573 K. The FeCl3-SbCl5-graphite bi-intercalation compound (GBC) with one SbCl5 layer is obtained when the temperature of the stage 5 FeCl3-GIC is held at 443 K and the temperature of SbCl5 at 373 K in the two-zone system. The stacking sequence of the GBC is found to be an admixture of G(FeCl3)GG(SbCl5)GGG(FeCl3)G and G(FeCl3)GGG(SbCl5)GG(FeCl3)G by XRD, where G, (FeCl3), and (SbCl5) are the graphite, FeCl3, and SbCl5 layers, respectively. The Raman spectrum of the GBC shows two peaks associated with the and modes at 1588 cm−1 and 1610 cm−1, respectively. For the temperatures of stage 5 FeCl3-GIC at 443 K and SbCl5 at 403 K in the two-zone system, the FeCl3-SbCl5-GBC with two SbCl5 layers is obtained. The stacking sequence of the GBC is determined to be an admixture of G(FeCl3)GG(SbCl5)GG(SbCl5)G(FeCl3)G and G(FeCl3)G(SbCl5)GG(SbCl5)GG(FeCl3)G In the Raman spectrum of this GBC, two peaks associated with the mode are observed at 1616 and 1624 cm−1.

Collapse of vibrational structure in spectra of resonant x-ray Raman scattering

1997 ◽  
Vol 56 (1) ◽  
pp. 256-264 ◽  
Author(s):  
Faris Gel’mukhanov ◽  
Timofei Privalov ◽  
Hans Ågren
Keyword(s):  
Raman Scattering ◽  
Vibrational Structure ◽  
X Ray

scholarly journals Exploring the fundamental effects of deposition time on the microstructure of graphene nanoflakes by Raman scattering and X-ray diffraction

CrystEngComm ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 312-318 ◽  
Author(s):  
Navneet Soin ◽  
Susanta Sinha Roy ◽  
Christopher O'Kane ◽  
James A. D. McLaughlin ◽  
Teck H. Lim ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Deposition Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Nanoflakes
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