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1.
We demonstrate the stimulated Raman scattering (SRS) of a binary solution of toluene and m-xylene at different volume concentrations
in liquid-core optical fiber (LCOF). The results show that SRS of three vibration modes of 1002 cm−1,2920 cm−1 and 3058 cm−1 bands are simultaneously generated at some volume concentrations. The 2920 cm−1 band and the 3058 cm−1 band are generated at one time, the SRS thresholds of the first-order Stokes of the 2920 cm−1 and 3058 cm−1 bands are lower compared with the second-order Stokes threshold of the 1002 cm−1 band and the main peak of the 2920 cm−1 and 3058 cm−1 bands changes from the 2920 cm−1 band to the 3058 cm−1 band as the volume concentrations are changed. We assume that these phenomena are attributed to the intermolecular Fermi
resonance. Raman scattering cross section (RSCS) theory is used to explain this assumption. 相似文献
2.
Li Wan Yiming Ren Bo Tang Xinhong Cheng Xuefei Zhang Dapeng Xu Hijun Luo Yunmi Huang 《Applied Physics A: Materials Science & Processing》2009,97(3):693-697
We report on the growth of NiSi film on Si(001) substrate with an orientation of NiSi[200]//Si[001]. Polarized Raman spectroscopy
was used to assign the symmetry of the NiSi Raman peaks. Raman peaks at 213 cm−1, 295 cm−1, and 367 cm−1 are assigned to be A
g
symmetry and peaks at 196 cm−1, and 254 cm−1 are B
3g
symmetry. 相似文献
3.
P. Martini M. Mazzoni S. Pestelli L. Ulivi M. Zoppi A. Diodati F. Fuso M. Allegrini E. Arimondo 《Il Nuovo Cimento D》1994,16(12):2011-2017
Summary We have used a Raman microprobe technique for the characterisation and the diagnostic of YBCO superconducting thin films deposited
by Pulsed-Laser Ablation (PLA) on MgO insulating substrates. Using polarisation analysis associated with sample rotations
we developed a method for films orientation determination without any request for absolute calibration of the Raman spectra.
The use of a bidimensional multichannel detector (OMA 4) allowed an overall detection time of 40 minutes. Each spectrum (shift
range from 100 cm−1 to 700 cm−1) takes about 600 seconds. The results of this detection were used to determine the oxygen content, from the position of the
Raman mode at 500 cm−1 Homogeneity was checked with the spatial resolution allowed by the dimension of the focused laser beam (10 μm).
Paper presented at the ?VII Congresso SATT?, Torino, 4–7 October 1994. 相似文献
4.
R. Ebert H. Pascher G. Appold H. G. Häfele 《Applied Physics A: Materials Science & Processing》1977,14(2):155-159
We report for the first time stimulated magneto-Raman scattering inp-type InSb. Two different Raman scattering processes were observed. The first one has a Raman shift of about 2cm−1/kG and is observed at magnetic fields up to 30kG. The other one is observable only at high magnetic fields above 30kG and
shows Raman shifts between 1.2cm−1 and 3.0cm−1 with a tuning rate of about 0.2cm−1/kG. The first process can be interpreted either as spin-flip Raman scattering by photo-excited electrons in the conduction
band or as Raman scattering by holes in the valence band involving transitions from heavy to light hole states. The other
Raman shift observed seems to occur on account of transitions between the heavy hole ladders. 相似文献
5.
Asmiet Ramizy Khalid Omar Z. Hassan Omar Alattas 《Journal of nanoparticle research》2011,13(12):7139-7148
Nanostructured GaN layers are fabricated by laser-induced etching processes based on heterostructure of n-type GaN/AlN/Si grown on n-type Si(111) substrate. The effect of varying laser power density on the morphology of GaN nanostructure layer is observed.
The formation of pores over the structure varies in size and shape. The etched samples exhibit dramatic increase in photoluminescence
intensity compared to the as-grown samples. The Raman spectra also display strong band at 522 cm−1 for the Si(111) substrate and a small band at 301 cm−1 because of the acoustic phonons of Si. Two Raman active optical phonons are assigned h-GaN at 139 and 568 cm−1 due to E2 (low) and E2 (high), respectively. Surface morphology and structural properties of nanostructures are characterized
using scanning electron microscopy and X-ray diffraction. Photoluminance measurement is also taken at room temperature by
using He–Cd laser (λ = 325 nm). Raman scattering is investigated using Ar+ Laser (λ = 514 nm). 相似文献
6.
Chan y Díaz E. Duarte-Moller A. Camacho Juan M. Castro-Rodríguez R. 《Applied Physics A: Materials Science & Processing》2012,106(3):619-624
SnO2 thin films have been deposited on glass substrates by pulsed Nd:YAG laser at different oxygen pressures, and the effects
of oxygen pressure on the physical properties of SnO2 films have been investigated. The films were deposited at substrate temperature of 500°C in oxygen partial pressure between
5.0 and 125 mTorr. The thin films deposited between 5.0 to 50 mTorr showed evidence of diffraction peaks, but increasing the
oxygen pressure up to 100 mTorr, three diffraction peaks (110), (101) and (211) were observed containing the SnO2 tetragonal structure. The electrical resistivity was very sensitive to the oxygen pressure. At 100 mTorr the films showed
electrical resistivity of 4×10−2 Ω cm, free carrier density of 1.03×1019 cm−3, mobility of 10.26 cm2 V−1 s−1 with average visible transmittance of ∼87%, and optical band gap of 3.6 eV. 相似文献
7.
The Raman spectrum of polycrystalline α-naphthylamine was recorded in the region 100–4000 cm−1. Polarisation measurements were made in CS2 and CHCl3 solutions. The infrared spectrum was recorded in nujol mull in the region 200–4000 cm−1. The resolution was better than 2 cm−1 and the accuracy of the measurements was within ± 2 cm−1 for all the spectra. Vibrational assignments have been proposed for the observed frequencies. Out of the 54 normal modes
of vibrations, 51 modes could be observed experimentally. 相似文献
8.
T. G. Adiks A. F. Bunkin V. A. Luk’yanchenko S. M. Pershin 《Physics of Wave Phenomena》2008,16(1):1-6
The contribution of impurity fluorescence was determined in the water Raman spectra excited by the second harmonic (λ = 532 nm) of a pulsed Nd:YAG laser. Water samples prepared by different techniques (tap water (undistilled), distilled water,
Milli-Q water, water for injections, and water subjected to cavitation treatment) were investigated. The Raman (bands at ν
2 ∼ 1550 cm−1 and ν
3 ∼ 3400 cm−1) and fluorescence (Stokes shift 2500 cm−1) signals were separated spectrally and according to the differences in the emission kinetics. It was established that all
investigated samples, including distilled and specially purified water for injections, exhibit afterglow. The highest sensitivity
to the presence of impurities was revealed near ∼ 2500 cm−1. The least contribution to the fluorescence signal was found in the water for injections. 相似文献
9.
We present an investigation of the nature of single-walled carbon nanotubes (SWCNTs) in a bundle by resonant Raman spectroscopy.
The calculation has been done for the three peak positions in radial breathing mode (RBM) spectra obtained by using a laser
excitation wavelength (γ) of 633 nm from He-Ne laser on SWNT bundle sample prepared by chemical vapor deposition (CVD) technique
using iron catalyst at 800°C. The detailed analysis in the present study is focused on peak positions 162 cm−1, 186 cm−1, and 216 cm−1. The firs step of the analysis is to construct a list of possible (n, m) pairs from the diameters calculated from the RBM peak positions. The parameters of SWNTs studied gives in-depth understanding
of many symmetry, resonance and characteristic properties of SWNT bundles. Our results indicate that the contribution of metallic
SWNTs in the bundle is small at RBM peak positions 162 cm−1, 186 cm−1 and in agreement with pervious results at peak position 216 cm−1. 相似文献
10.
The 2H polytype of a SnS2 layered crystal has been studied using Raman spectroscopy at pressures of up to 5 GPa in a diamond anvil cell. The Raman
frequency of the intralayer mode increases linearly with increasing pressure at baric coefficients of 5.2 cm−1/GPa for P<3 GPa and 3.4 cm−1/GPa for P>3 GPa. This change in the baric coefficient for Raman scattering and the available data on X-ray measurements of the compressibility
of 2H-SnS2up to 10 GPa suggest that the crystal structure undergoes a transformation at about 3 GPa. 相似文献
11.
Distinctive optical properties of single-wall carbon nanotubes (SWNT) are highly sensitive to variations in the environment.
Here, we have studied SWNT in aqueous suspensions at a low (less than 0.1 μg ml−1) concentration by four-wave mixing (FWM) spectroscopy in the spectral bands of 0.1 to 10 cm−1 (≈300 GHz) and 100 to 250 cm−1 (3 to 7.5 THz). We directly investigated the hydration layers around SWNT. A comparison of the FWM spectra of an SWNT aqueous
suspension and Milli-Q water shows a considerable increase in the intensity of low-frequency Raman modes, which are attributed
to the rotational transitions of H2O2 and H2O molecules. We explain the observed phenomenon by the hydrogen peroxide production and formation of a low-density depletion
layer at the water-nanotube interface. We have observed several SWNT radial breathing modes ω
RBM =118.5, 164.7, and 233.5 cm−1 in an SWNT aqueous suspension and estimated the corresponding SWNT diameters as ≈2.0, 1.5, and 1 nm. 相似文献
12.
In this paper we report on measurements of spin-flip-Raman gain inn-InSb as a function of the magnetic field. The measurements were carried out at temperatures of 1.8 K and 4.2 K and at a carrier
concentration of 1.35×1015 cm−3. The Raman cross sections obtained from these results, e.g. 1.25×10−20 cm2/sr at a magnetic field of 10 kG and a pump frequency of 1884.35 cm−1, agree very well with those theoretically predicted by Wherrett and Wolland.
Furthermore, these measurements yield line shapes and linewidths of the spontaneous scattering (100–1500 MHz) and allow the
determination of the effectiveg-value with an accuracy known from ESR-investigations. These results are discussed in terms of already published theoretical
investigations. 相似文献
13.
A. V. Bazhenov V. V. Kveder A. A. Maksimov I. I. Tartakovskii R. A. Oganyan Yu. A. Ossipyan A. I. Shalynin 《Journal of Experimental and Theoretical Physics》1998,86(5):1030-1034
Raman light scattering and IR absorption spectra of samples containing multilayer carbon nanotubes in different stages of
purification by the selective oxidation technique have been investigated. It was found that the Raman spectra of carbon nanotubes
exhibit softening of the mode at 1582 cm−1 corresponding to E
2g
vibrations of graphite hexagons and a line at 120 cm−1 due to the radial vibrations of nanotubes. In IR absorption spectra measured in the region of 0.07–0.3 eV, several sets of
lines with a spacing of 15 meV (120 cm−1) between lines of each group have been detected. We suggest that each group corresponds to electron transitions generating
electron-hole pairs in semiconducting nanotubes and contains a phononless 00-line and its phonon replicas with spacing between
them equal to the “breathing” mode energy of 120 cm−1. Measurements of electric conductivity at a frequency of 9300 MHz indicate that, in addition to semiconducting nanotubes,
the samples contain nanotubes with properties of a highly disordered semimetal.
Zh. éksp. Teor. Fiz. 113, 1883–1891 (May 1998) 相似文献
14.
The broadening and shift of the Q bands of the 1388/1285-cm−1 Fermi doublet of carbon dioxide have been measured by means of the spectroscopy of coherent anti-Stokes Raman scattering
in a wide density range realized at compression in dense gaseous and liquid states. The spectrum of the low-frequency Q band exhibits an essential narrowing upon the compression of the liquid in the density range of 320–400 amagat from a maximum
width of about 2.2 cm−1 to about 1.7 cm−1 determined by elastic dephasing. The observed dependence is connected with the progressive narrowing of the spectral contribution
attributed to the collapsed rotational structure. 相似文献
15.
V. I. Vettegren V. B. Kulik A. V. Savitskii O. I. Fetisov V. V. Usov 《Technical Physics》2010,55(5):743-746
The solidification of a solution of poly(acrylonitrile) (PAN) in dimethylsulfoxide (DMSO) upon introduction of water into
the solution is studied by Raman spectroscopy. In the absence of water, DMSO molecules are found to produce dipole-dipole
bonds with PAN molecules. Upon the introduction of water, DMSO molecules produce hydrogen bonds with it and bands at 1005
and 1015 cm−1 appear in the Raman spectrum, which are assigned to the valence vibrations of S=O bonds involved in the hydrogen bonds. Simultaneously,
water molecules produce hydrogen bonds with PAN molecules: R-C≡N...H-O-H...N≡C-R, where R is the carbon skeleton of a PAN
molecule. Accordingly, a band at 2250 cm−1 arises in the Raman spectrum, which is assigned to the valence vibrations of C≡N bonds producing hydrogen bonds with a water
molecule. When the water content is low and the DMSO concentration is high, the length of the hydrogen bonds varies in wide
limits and the band at 2250 cm−1 is wide. As the water content rises, DMSO molecules come out of PAN, the variation of the hydrogen bond length in it decreases
(the band at 2250 cm−1 narrows), and a high-viscosity system (gel) arises that consists of PAN molecules bonded to water molecules via “equally
strong” hydrogen bonds. 相似文献
16.
We report an efficient operation of a kilohertz nanosecond extracavity KGd(WO4)2 (KGW) crystal Raman yellow laser, which is pumped by a 532 nm lasers based on pulse laser diode (LD) side-pumped ceramic
Nd: YAG, BBO electro-optical Q-switched and LBO crystal extracavity frequency doubling. With the 5 W, 10 ns and 1 kHz output
power pumped at 532 nm, we obtained 2.58 W, 7.4 ns, 1 kHz second Stokes Raman laser output at 579.54 nm for 768 cm−1 Raman shift of KGW crystal, corresponding to a conversion efficiency of 51.4%. By changing the KGW crystal orientation, we
further obtained 3.18 W, 7.8 ns, 1 kHz Raman pulses at 588.33 nm for 901 cm−1 Raman shift, corresponding to a conversion efficiency of 63.3%. The beam quality factors M2 of 579.54 and 588.33 nm were (M
x−579.542 = 5.829, M
y−579.542 = 6.336) and (M
x−588.332 = 6.405, M
y−588.332 = 6.895), respectively. 相似文献
17.
H. Hobert H.H. Dunken G. Peiter W. Stier M. Diegel H. Stafast 《Applied Physics A: Materials Science & Processing》1999,69(1):69-76
A large number of thin SiC films, prepared at different conditions by KrF excimer laser ablation of solid SiC targets and
deposition onto Si substrates (some onto quartz glass (QG) and yttrium-stabilized zirconia (YSZ)) were characterized by infrared
and Raman spectroscopy. The films consisted of nano- and microcrystalline SiC and contained nanocrystalline carbon in the
case of QG or YSZ substrates. Raman spectra of nanocrystalline SiC (grains <30 nm) reflect the phonon density-of-state function
of SiC by broad scattering effects at 220–600 and 650–950 cm−1. Medium-size crystallites are represented by a relatively narrow asymmetric band at 790 cm−1 and crystallites >200 nm by an additional asymmetric band at 960 cm−1. Small satellite bands at 760 and 940 cm−1, attributed to SiC surface layers, were resolved in some well-ordered samples. Optical modelling was needed to interpret
the IR spectra. SiC films could be represented by an effective medium model containing a SiC host phase and embedded particles
with free charge carriers. The crystalline order of SiC films can be estimated from the parameters of the SiC oscillators.
Received: 5 October 1998 / Accepted: 8 January 1999 / Published online: 5 May 1999 相似文献
18.
E. S. Zhukova N. P. Aksenov B. P. Gorshunov Yu. G. Selivanov I. I. Zasavitskii D. Wu M. Dressel 《Physics of the Solid State》2011,53(4):810-814
The spectra of epitaxial Pb1 − x
Eu
x
Te (0 ≤ x ≤ 0.37) solid solution layers grown on BaF2 and Si substrates have been investigated over a wide frequency range 7–4000 cm−1 at temperatures of 5–300 K. Apart from the phonon and impurity absorption lines, the absorption in a local mode in PbEuTe
layers of substrates and buffer layers has been observed in the frequency range 110–114 cm−1. As the temperature decreases from 300 to 5 K, the transverse phonon mode softens from 33.0 to 19.5 cm−1. 相似文献
19.
L. P. Avakyants V. S. Gorelik É. M. Temper S. M. Shcherbina 《Physics of the Solid State》1999,41(8):1369-1372
Structure in the Raman scattering spectra of near-surface n-GaAs layers (n=2×1018 cm−3) implanted with 100 keV B+ ions in the dose range 3.1×1011–1.2×1014 cm−2 is investigated. The qualitative and quantitative data on the carrier density and mobility and on the degree of amorphization
of the crystal lattice and the parameters of the nanocrystalline phase as a result of ion implantation are obtained using
a method proposed for analyzing room-temperature Raman spectra.
Fiz. Tverd. Tela (St. Petersburg) 41, 1495–1498 (August 1999) 相似文献
20.
Mohammed A. Gondal Abdulaziz A. Bagabas Mohamed A. Dastageer 《Journal of nanoparticle research》2011,13(9):3835-3842
Cadmium sulfide (CdS) quantum dots (QDs), capped with cetyltrimethylammonium bromide (CTAB), and was synthesized as stable,
aqueous, colloidal nanofluid. A series of nine intense, well-resolved emission lines between 400 and 750 nm were observed
for the first time when exciting the CdS QDs nanofluid with a 355-nm high energy pulsed Nd:YAG laser radiation. The energy
separation between any two successive emission lines equals to the characteristic overtone energy of 295 cm−1 of the longitudinal optical phonon of CdS QDs. In addition, recording the PL spectrum by using a xenon broad band light source
resulted in the observation of this characteristic overtone energy of 295 cm−1. In agreement with this photoluminescence characteristic, Raman spectrum exhibited four prominent Stokes lines with Raman
shift equal to and multiple of 295 cm−1. Transmission electron microscopy investigation showed that the CdS QDs were spherical with hexagonal wurtzite structure
and had a size in the range of 5–10 nm. 相似文献