Artykuły w czasopismach: „Raman shift”

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Yang, XueXian, Yonghui Liu, Xin Juan Liu, Jin Zhang Peng, Heping Zhao i Chang Qing Sun. "Composition- and Temperature-Resolved Raman Shift of Silicon". Applied Spectroscopy 72, nr 4 (12.01.2018): 598–603. http://dx.doi.org/10.1177/0003702817744218.

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We formulated the composition and temperature dependence of the Si and Si1– xGe x Raman shift from the perspectives of bond order–length–strength correlation and local bond average approach. It is verified that the Raman shift Δω varies in the form of Δω ∝ zE1/2/ d, with inclusion of bond length d and energy E changing with temperature and composition. Numerical reproduction of the thermally induced Si1– xGe x phonon softening indicates that bond thermal expansion and energy loss dictate the frequency redshift, which resulted in quantitative information on the bond energy and the reference frequencies from which the Raman shifts proceed. Observations not only gain deeper insight into the mechanism of the Raman shift but also demonstrate the revealing power of Raman technique for the bonding thermodynamics.

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Gao, Yukun, i PG Yin. "Synthesis of cubic CdSe nanocrystals and their spectral properties". Nanomaterials and Nanotechnology 7 (1.01.2017): 184798041770174. http://dx.doi.org/10.1177/1847980417701747.

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The cadmium selenide nanocrystals are prepared by colloidal chemistry under mild conditions. X-ray diffraction and high-resolution transmission electron microscopy measurements indicate that as-prepared cadmium selenide nanocrystals are zinc blende cubic structure. We carry out an analysis of quantum size effect in the Raman spectra of cadmium selenide nanocrystals performed by utilizing the chemical bond theory of Raman peak shift developed recently. It is revealed that the shifts of Raman peaks in cadmium selenide nanocrystals result from the overlapping of the quantum effect shifts and surface effect shifts. The sizes of the as-prepared cadmium selenide nanocrystals obtained by employing the Raman peak shift theory are in good agreement with the nanocrystal sizes determined by high-resolution transmission electron microscopy.

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Fountain, Augustus W., Charles K. Mann i Thomas J. Vickers. "Routine Wavenumber Calibration of an FT-Raman Spectrometer". Applied Spectroscopy 49, nr 7 (lipiec 1995): 1048–53. http://dx.doi.org/10.1366/0003702953964886.

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A readily automated procedure for testing and calibrating the wavenumber shift scale of an FT-Raman spectrometer is described. The procedure uses atomic lines as wavenumber standards. An apodization procedure is used in accurately determining the line positions to a fraction of the sampling interval. A fiber-optic bundle conveniently couples the output from a hollow cathode lamp to the collection optics of the Raman accessory. Results are reported and compared for both thorium and neon atomic lines. Acetonitrile is suggested as a wavenumber shift standard, and peak shifts have been measured for its major features. Peak shift values are reported for 11 lines of cyclohexane.

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Zhou, Minghao, i Rongying Dai. "Study on Characteristic Raman Shift Screening Method Based on MPA for Raman Spectrum of Mine Water Inrush Source". Scientific Programming 2022 (23.08.2022): 1–8. http://dx.doi.org/10.1155/2022/5202265.

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In the process of mine water inrush disaster prevention, accurate and rapid identification of water inrush source type is of great significance to coal mine safety production. However, traditional hydrochemical methods have shortcomings such as time-consuming and complex detection. Therefore, a new idea of identifying mine water inrush source by Raman spectroscopy is proposed. Goaf water, roof sandstone fissure water, Ordovician limestone water, Taiyuan limestone water, and surface water as well as their mixed water samples are selected as research objects, and Raman spectral data of different water samples are collected by the Raman spectroscopy system. To eliminate the influence of laser power fluctuation and spectrometer system noise in Raman spectrum acquisition, detrend correction (DC), multiplicative scatter correction (MSC), standard normal variate transformation (SNV), first derivative (FD), and mean centering (MC) were used to preprocess the raw Raman spectra. Due to the large dimension and long analysis time of Raman spectrum data, the marine predator algorithm (MPA) is used to screen the characteristic Raman shifts of the Raman spectrum of water samples, and the characteristic Raman shift information that can best characterize the mine water samples is obtained. Finally, to verify the feasibility of MPA screening the characteristic Raman shifts of Raman spectrum of mine water inrush source, the selected characteristic Raman displacement information is used as input to construct BP neural network (BP), k-nearest neighbor algorithm (KNN), support vector machine (SVM), and decision tree (DT) classification models, respectively. Experiments show that SNV has the best preprocessing effect on the raw Raman spectrum, which can effectively eliminate part of the noise in the Raman spectrum data and improve the accuracy of Raman spectrum identification. Using MPA, 226 characteristic Raman shifts can be screened from 2048 Raman data points, reducing the number of Raman shifts to 11.04%, and the modeling accuracy of characteristic Raman shift information screened by MPA is higher than that of full Raman data. In addition, the average analysis speed of BP, KNN, SVM, and DT water source identification models is 7.61 times faster than that of all Raman data. The results show that MPA is adopted to screen the characteristic Raman displacement of mine water source Raman spectrum, which can effectively reduce the redundancy of Raman spectral data and greatly improve the speed of Raman spectral analysis, which is of great significance to ensure the real-time detection of the mine water source.

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Izadshenas, Saeid, Piotr Masłowski, Tobias Herr i Karolina Słowik. "Multiresonant metasurface for Raman spectroscopy beyond single molecule detection level". EPJ Applied Metamaterials 9 (2022): 11. http://dx.doi.org/10.1051/epjam/2022009.

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A metasurface in the metal-insulator-grating configuration is designed and optimised to support enhancement of coherent Raman signal of selected molecules orders of magnitude above the single-molecule detection threshold. The tunability is demonstrated by adjusting the structure to match selected Raman peaks of rhodamine, however, its spectral response is broad enough to cover a range of Raman shifts. Finally, the grating allows switching between distinct values of Raman shift with a single metasurface illuminated at different angles.

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Wang, Can, Bo Lin Cheng, S. Y. Wang, S. Y. Dai i Zhao Hui Chen. "Raman Spectra Study on Multilayered Compositional Graded (Ba_0.8Sr_0.2)(Ti_1-xZr_x)O₃ Thin Films". Key Engineering Materials 280-283 (luty 2007): 1909–12. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1909.

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Compositional graded thin films of (Ba0.8Sr0.2)(Ti1-xZrx)O3 (BSTZ) are grown on MgO by pulsed laser deposition technique with four BSTZ ceramic targets. Gradients of composition are achieved by artificially tailoring composition in multilayered thin films to form compositional graded layers (CGL). In each CGL four individual layers of BSTZ with x = 0.36, 0.18, 0.08 and 0 are grown^in series with equal thickness. Three kinds of CGL samples comprising one, two or four CGLs have been elaborated with the same total thickness by varying the thickness of each CGL. Raman spectra show existence of tetragonal structure in all the multilayered BSTZ thin films. Raman peak at 535 cm-1 shifts to high frequency with increasing of compositional gradient, and the peak at 750 cm-1 also shows a small shift to high frequency. Moreover, other Raman peak is observed at about 830 cm-1, which is associated with phonon mode of cubic phase, and such peak shifts towards lower frequency with increasing of compositional gradient. The shift of Raman peak is related to variation of internal stress in BSTZ thin film due to increasing compositional gradient.

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Amaechi, Ifeanyichukwu C., Andreas Ruediger i Alain Pignolet. "Phonon confinement and particle size effect on the low-frequency Raman mode of aurivillius phase Bi₄Ti₃O₁₂ powders". RSC Advances 13, nr 8 (2023): 4917–23. http://dx.doi.org/10.1039/d2ra06297f.

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Both Raman shift, ω ∝ x−0.73, and linewidth, Γ ∝ x−0.38, exhibit a power law dependence on the particle size. The particle size-dependent lattice constant contributed to satisfactory explanation of the Raman shift.

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Piluso, Nicolò, Massimo Camarda, Ruggero Anzalone, Andrea Severino, Antonino La Magna, Giuseppe D'Arrigo i Francesco La Via. "Raman Stress Characterization of Hetero-Epitaxial 3C-SiC Free Standing Structures". Materials Science Forum 679-680 (marzec 2011): 141–44. http://dx.doi.org/10.4028/www.scientific.net/msf.679-680.141.

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Raman microscopy has been used to study the stress distribution on 3C-SiC/Si(100) micro-machined free standing structures. Linear scans along different structures reveal similar trends of the TO mode Raman Shift. We have found that, independently of the microstructure considered, the Raman frequency decreases close to the undercut. We compare our experimental measurements with FEM simulations finding that, close to the undercut, the stress tensor becomes non-diagonal, modifying the Raman shift to stress relation.

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Suda, Jun, i Petr Zverev. "Temperature Dependence of Raman Frequency Shift in SrWO4 Crystal Studied by Lattice Dynamical Calculations". Crystals 9, nr 4 (7.04.2019): 197. http://dx.doi.org/10.3390/cryst9040197.

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The frequency shift of the Raman modes in strontium tungstate (SrWO4) was investigated in the temperature range from 15 to 295 K. The experimental temperature dependence of the shift was analyzed using both the lattice dynamical calculations and the lattice perturbative approach. We found that the quartic anharmonic term of the first-order perturbation and the cubic term of the second-order perturbation, as well as the thermal expansion, contribute to the temperature shift of the highest-frequency Ag(ν1) mode. The values of the temperature sensitivity of the frequency shift of the Raman modes at room temperature were measured, which is important for developing high-power crystalline Raman lasers and frequency shifters.

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Shin, Y. J., W. J. Kim, H. Y. Kim i W. Bahng. "Dislocation Analysis of 4H-/6H-SiC Single Crystals Using Micro-Raman Spectroscopy". Materials Science Forum 740-742 (styczeń 2013): 481–84. http://dx.doi.org/10.4028/www.scientific.net/msf.740-742.481.

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Micro-Raman spectroscopy is an excellent non-destructive analysis method, which compensates for disadvantages of KOH method. Raman shift of A1(LO) and E1(TO) band at threading screw dislocation(TSD) were investigated in n-type on/off-axis 4H- and 6H-SiC single crystal wafers by Micro-Raman scattering at room temperature. The results showed that A1(LO) band were shifted toward higher frequency while the E1(TO) band were shifted toward lower frequency on the on-axis wafers. The shifts are caused by increasing electron concentration and lattice disorder near the dislocation core, respectively. In the off-axis wafers, no shifts were observed possibly due to the measurement geometry which does not contain whole dislocation core.

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Chertkova, Nadezda, Shigeru Yamashita, Eiji Ito i Akira Shimojuku. "High-pressure synthesis and application of a 13C diamond pressure sensor for experiments in a hydrothermal diamond anvil cell". Mineralogical Magazine 78, nr 7 (grudzień 2014): 1677–85. http://dx.doi.org/10.1180/minmag.2014.078.7.11.

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AbstractPolycrystalline, cubic 13C diamond was synthesized from amorphous carbon in the Kawai-type multianvil apparatus at 21 GPa and at a temperature greater than 2350ºC. The polycrystalline diamond was homogeneous with a small grain size (10–20 μm) and a sharp Raman peak, and thereby was suitable as a pressure sensor for the experiments in a hydrothermal diamond anvil cell. Pressure- and temperature-dependence of the Raman shift of the synthesized 13C diamond was investigated in situ at simultaneous high pressures and high temperatures in the hydrothermal diamond anvil cell, using the ruby fluorescence line, quartz Raman shift and H2O phase transitions as pressure references. It was observed that the frequency shift with pressure is independent of temperature and vice versa up to 500ºC and 4.2 GPa. The present study indicates that the 13C diamond Raman shift can be used for pressure determination with an accuracy better than ±0.3 GPa under the conditions examined.

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Kai, Akira, Masao Takegoshi i Tetsuo Shoji. "In Situ Micro Raman Spectroscopy for Characterization of Oxide Film Formed on the New Surface and for Measurements of the Stress of Oxide Film Formed on 304L Stainless Steel". Key Engineering Materials 261-263 (kwiecień 2004): 913–18. http://dx.doi.org/10.4028/www.scientific.net/kem.261-263.913.

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Environmentally assisted cracking (EAC) consists of two distinct events viz., i) crack initiation and ii) crack propagation. On a smooth surface, the EAC initiates by the rupture or by the degradation of the surface film due to the combined action of stress and an electrochemical reaction of the materials with the environment. The mechanical properties of the surface oxide films are also important considerations when determining the susceptibility to EAC. In this research, Micro Raman Spectroscopy(MRS) was applied for in-situ oxides characterization and for in-situ measurements of the stress in oxide film formed on the surface of 304L stainless steel during the scratching electrode and the slow strain rate test (SSRT), respectively. The passive oxide film growth formed on the bare surface was continuously monitored by MRS as a function of time. For stress measurements, Cr2O3 was focused on and Raman shift at Cr2O3 peak of Raman spectrum was measured continuously. The strain rate was 8.2×10-7 /sec. . In the initial stage of SSRT, the Raman shift of surface film decreased gradually with strain. At 5% strain, the Raman shift of surface film increased rapidly to around the initial value of Raman shift. It is considered that the surface film was ruptured at this time. At 5% strain, the shift value of Raman peak of Cr2O3 reached to 5cm-1. This value (5cm-1) corresponds to 1.2GPa which value of tensile stress is calculated from reference data. These characteristics of oxide film will be implemented into the theoretical formulation of EAC and their implication to EAC growth rate will be discussed.

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Tardieu, A., F. Cansell i J. P. Petitet. "Comparison of the Raman pressure shift and the Raman temperature shift of benzene and diamond with the ruby soale". High Pressure Research 5, nr 1-6 (kwiecień 1990): 779–81. http://dx.doi.org/10.1080/08957959008246256.

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Zerda, T. W., X. Song i J. Jonas. "Raman Study of Intermolecular Interactions in Supercritical Solutions of Naphthalene in CO2". Applied Spectroscopy 40, nr 8 (listopad 1986): 1194–99. http://dx.doi.org/10.1366/0003702864507657.

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The high-pressure Raman spectra of the v1 and 2 v2 Fermi doublet of CO2 and the C-H stretching, C-H bending and C-C-C breathing modes of naphthalene have been studied at pressures varying up to 2000 bar and temperatures between 60 and 90°C. The naphthalene bands show a blue frequency shift with increasing density, whereas a red shift for the Fermi resonance free stretching mode of CO2 is observed with increasing density. The blue shift is explained in terms of repulsive interactions probed by the naphthalene vibrations, while the red shift is related to the attractive forces dominating in the intermolecular potential as seen by the CO2 stretching mode. The experimental results support the validity of the site-to-site model of intermolecular potential. The intermolecular potential between naphthalene and CO2 is assumed to be anisotropic, and the proposed electrostatic quadrupole-quadrupole model of these interactions effectively explains the anisotropy in the intermolecular potential, the energy of association, and the frequency shifts.

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Cetinel, A., N. Artunç, G. Sahin i E. Tarhan. "Influence of applied current density on the nanostructural and light emitting properties of n-type porous silicon". International Journal of Modern Physics B 29, nr 15 (25.05.2015): 1550093. http://dx.doi.org/10.1142/s0217979215500939.

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Effects of current density on nanostructure and light emitting properties of porous silicon (PS) samples were investigated by field emission scanning electron microscope (FE-SEM), gravimetric method, Raman and photoluminescence (PL) spectroscopy. FE-SEM images have shown that below 60 mA/cm 2, macropore and mesopore arrays, exhibiting rough morphology, are formed together, whose pore diameter, pore depth and porosity are about 265–760 nm, 58–63 μ m and 44–61%, respectively. However, PS samples prepared above 60 mA/cm 2 display smooth and straight macropore arrays, with pore diameter ranging from 900–1250 nm, porosity of 61–80% and pore depth between 63–69 μ m . Raman analyses have shown that when the current density is increased from 10 mA/cm 2 to 100 mA/cm 2, Raman peaks of PS samples shift to lower wavenumbers by comparison to crystalline silicon (c-Si). The highest Raman peak shift is found to be 3.2 cm -1 for PS sample, prepared at 90 mA/cm 2, which has the smallest nanocrystallite size, about 5.2 nm. This sample also shows a pronounced PL, with the highest blue shifting, of about 12 nm. Nanocrystalline silicon, with the smallest nanocrystallite size, confirmed by our Raman analyses using microcrystal model (MCM), should be responsible for both the highest Raman peak shift and PL blue shift due to quantum confinement effect (QCE).

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Radtke, Mariusz, i Christian Hess. "Operando Raman Shift Replaces Current in Electrochemical Analysis of Li-ion Batteries: A Comparative Study". Molecules 26, nr 15 (1.08.2021): 4667. http://dx.doi.org/10.3390/molecules26154667.

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Li-rich and catalytically active γ-LixV2O5 (x = 1.48) was investigated as a cathode for its heterogeneous charge transfer kinetics. Using a specially designed two-electrode system lithium half cell, Butler–Volmer analysis was performed, and Raman spectra were acquired in 18 mV intervals. A direct correlation was observed between the Raman shift of the active modes Ag,Bg, Au, and Bu, and the development of the Faraday current at the working electrode. The Raman intensity and the Raman shift were implemented to replace the current in a Tafel plot used for the analysis of Butler–Volmer kinetics. Striking similarities in the charge transfer proportionality constants α were found for current and Raman-based analysis. The potential of this new method of Raman-aided electrochemical detection at the diffraction limit is discussed.

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Sun, Xiu Ping, i Zai Chao Yu. "Study on Raman Spectra of Zinc Gluconate under Effect of Different Solvent". Key Engineering Materials 552 (maj 2013): 111–14. http://dx.doi.org/10.4028/www.scientific.net/kem.552.111.

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Raman spectrum is a kind of characteristic spectrum. The information of molecular vibration and rotation can be obtained by studying Raman spectrum. Raman spectrum will be changed because of molecular interaction under effect of different solvent. We selected zinc gluconate as the object of research. Zinc gluconate is dissolved respectively in ethyl chloride, benzene, ring of ethane，chloroform, acetic acid, ethylene oxide, n-propanol, n-butanol solution, and Raman spectra were tested. The change of molecular internal structure and the interaction of molecular functional groups are studied by means of measuring Raman frequency shift, bandwidth, and light intensity. Thus, the information of solute structure change can be obtained. Experiments show that when zinc gluconate dissolved in the organic solvent, molecular gap became larger, its velocity increased, and stretching vibration of associating OH key group became strong. Methylenes in polar and non-polar molecule interact, and the polarization changed. In different polar solvents, Raman spectra had different changes. When the bond length increases，the stretching vibration frequency of molecules moves to the direction of low frequency. It produces red shift instead of blue shift. The results of this paper provide a basis to study molecular interactions further.

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Sahu, Sumit Ranjan, Mayanglambam Manolata Devi, Puspal Mukherjee, Pratik Sen i Krishanu Biswas. "Optical Property Characterization of Novel Graphene-X (X=Ag, Au and Cu) Nanoparticle Hybrids". Journal of Nanomaterials 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/232409.

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The present investigation reports new results on optical properties of graphene-metal nanocomposites. These composites were prepared by a solution-based chemical approach. Graphene has been prepared by thermal reduction of graphene oxide (GO) at 90°C by hydrazine hydrate in an ammoniacal medium. This ammoniacal solution acts as a solvent as well as a basic medium where agglomeration of graphene can be prevented. This graphene solution has further been used for functionalization with Ag, Au, and Cu nanoparticles (NPs). The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to reveal the nature and type of interaction of metal nanoparticles with graphene. The results indicate distinct shift of graphene bands both in Raman and UV-Vis spectroscopies due to the presence of the metal nanoparticles. Raman spectroscopic analysis indicates blue shift of D and G bands in Raman spectra of graphene due to the presence of metal nanoparticles except for the G band of Cu-G, which undergoes red shift, reflecting the charge transfer interaction between graphene sheets and metal nanoparticles. UV-Vis spectroscopic analysis also indicates blue shift of graphene absorption peak in the hybrids. The plasmon peak position undergoes blue shift in Ag-G, whereas red shift is observed in Au-G and Cu-G.

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Sokalski, Peter, Zherui Han, Gabriella Coloyan Fleming, Brandon Smith, Sean E. Sullivan, Rui Huang, Xiulin Ruan i Li Shi. "Effects of hot phonons and thermal stress in micro-Raman spectra of molybdenum disulfide". Applied Physics Letters 121, nr 18 (31.10.2022): 182202. http://dx.doi.org/10.1063/5.0122945.

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Micro-Raman spectroscopy has become an important tool in probing thermophysical properties in functional materials. Localized heating by the focused Raman excitation laser beam can produce both stress and local nonequilibrium phonons in the material. Here, we investigate the effects of hot optical phonons in the Raman spectra of molybdenum disulfide and distinguish them from those caused by thermally induced compressive stress, which causes a Raman frequency blue shift. We use a thermomechanical analysis to correct for this stress effect in the equivalent lattice temperature extracted from the measured Raman peak shift. When the heating Gaussian laser beam is reduced to 0.71 μm, the corrected peak shift temperature rise is 17% and 8%, respectively, higher than those determined from the measured peak shift and linewidth without the stress correction, and 32% smaller than the optical phonon temperature rise obtained from the anti-Stokes to Stokes intensity ratio. This nonequilibrium between the hot optical phonons and the lattice vanishes as the beam width increases to 1.53 μm. Much less pronounced than those reported in prior micro-Raman measurements of suspended graphene, this observed hot phonon behavior agrees with a first-principles based multitemperature model of overpopulated zone-center optical phonons compared to other optical phonons in the Brillouin zone and acoustic phonons of this prototypical transition metal dichalcogenide. The findings provide detailed insight into the energy relaxation processes in this emerging electronic and optoelectronic material and clarify an important question in micro-Raman measurements of thermal transport in this and other two-dimensional materials.

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Suss, Nicole, Anna Ritscher, Martin Lerch i Ilias Efthimiopoulos. "Anharmonic Effects in Ordered Kesterite-Type Cu2ZnSnS4". Solids 2, nr 4 (24.11.2021): 385–94. http://dx.doi.org/10.3390/solids2040024.

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We performed an in-depth investigation and analysis of the effect of temperature on the Raman-active A-modes of bulk kesterite-type Cu2ZnSnS4 within the 300–460 K temperature range. We acquired the individual contributions to each Raman mode, namely, the thermal expansion and anharmonic interactions terms responsible for the Raman shift and broadening with temperature. Our results indicate that the Raman shift with temperature is dominated by the thermal expansion term, whereas the broadening is mainly governed by three-phonon damping processes in this material. Considering relevant results from the literature, it appears that dimensionality is a key factor in regulating the dominant phonon decay mechanism.

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Li, H., X. W. He, H. J. Xiao, H. N. Du, J. Wang i H. X. Zhang. "Size-dependent Raman shift of semiconductor nanomaterials determined using bond number and strength". Phys. Chem. Chem. Phys. 19, nr 41 (2017): 28056–62. http://dx.doi.org/10.1039/c7cp05495e.

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Endo, Masanori, Haruki Uchiyama, Yutaka Ohno i Jun Hirotani. "Temperature dependence of Raman shift in defective single-walled carbon nanotubes". Applied Physics Express 15, nr 2 (10.01.2022): 025001. http://dx.doi.org/10.35848/1882-0786/ac4678.

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Abstract Raman scatterings of both pristine and defective single-walled carbon nanotubes were measured. Defects on carbon nanotubes (CNTs) were induced by UV/O3 treatment, and the correlation between the temperature dependence of the Raman shift of the G-band and the crystallinity of CNTs was investigated. In the temperature range of 250–600 K, a gradual negative change in the slope was observed; the linear shift of the Raman G-band frequency with respect to temperature increased as the crystallinity deteriorated. This phenomenon is attributed to the increase in the fourth-order phonon–phonon scattering interaction resulting from the induced defects.

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Yulianto, Edy, Marsetiayu Ningsih, Wahyu Bahari, Ahmad Musthofa, Galuh Prihantoro i Fifit Astuti. "Raman Spectroscopy for Non-Destructive Detection of Pesticide on Guava Peel". Jurnal Penelitian Pendidikan IPA 9, nr 4 (30.04.2023): 2025–29. http://dx.doi.org/10.29303/jppipa.v9i4.3202.

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Pesticides are one of the substances that are widely used to protect plants from pests and plant diseases, and their use must be controlled for the public health. Currently, the pesticide contamination is determined by chromatographic, but this technique is destructive and not easy to implement. Therefore, this research is proposed to overcome these problems. Raman scattering technique as a non-destructive testing technique and easy to implement is used in this research. This technique utilizes Raman scattering resulting from laser excitation in a sample. Pesticide detection was carried out by observing the difference in Raman shift wavelength between samples containing pesticides and samples that did not contain pesticides. The experiments were done on guava peels with coated pesticide delthametrin 25 g/l. By excitation with laser wavelengths 532 nm and 785 nm, the differences in Raman shifts at wavelengths 1,225 nm and 1,480 for samples coated pesticide, and Raman shifts at wavelengths 1,008 nm and 1,480 nm for samples which is treated are obtained, respectively. From this research, it can be concluded that Raman scattering technique can be used as non-destructive and easy technique for detection pesticide contamination.

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Терещенко, Д. П., С. Н. Сметанин, А. Г. Папашвили, К. А. Губина, Ю. А. Кочуков, С. А. Солохин, М. Н. Ершков i in. "Обогащение спектра многоволновой пикосекундной генерации синхронно-накачиваемого ВКР-лазера на кристалле Sr(MoO_4)-=SUB=-0.8-=/SUB=-(WO_4)-=SUB=-0.2-=/SUB=-". Журнал технической физики 93, nr 4 (2023): 488. http://dx.doi.org/10.21883/jtf.2023.04.55036.270-22.

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For the first time to our knowledge, a single-phase solid solution Sr(MoO4)0.8(WO4)0.2 was used as an active medium of a Raman laser. Using the high-intensity synchronous picosecond pumping satisfying the condition of phase capture of the parametric Raman interaction on the second vibrational mode made it possible to oscillate six components of Raman radiation with a combined frequency shift on the first (888 cm–1) and second (327 cm–1) vibrational modes in the wavelength range of 1194-1396 nm. Oscillation efficiency of the multiwavelength Raman laser radiation was as high as 10%. By detuning the Raman laser cavity length, the pulse shortening down to 6 ps for the Raman laser radiation components with the combined frequency shift was obtained, which is an order of magnitude shorter than the pumping pulse duration (64 ps).

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Garasevych, S., M. Iakhnenko, O. Slobodyanyuk i I. Vaskivskyi. "Abnormal shifts in Raman spectra of deuterated cytidine and 6-azacytidine". Spectroscopy 24, nr 3-4 (2010): 191–95. http://dx.doi.org/10.1155/2010/107694.

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It was revealed that some peaks in Raman spectra of cytidine, 6-azacytidine (6-azaC), and cytosine dissolved in D2O are shifted to high frequencies in respect to their positions in spectra of H2O solution. Such “blue shifts” occur due to deuteration of the nucleoside molecule itself but not due to effect of deuterated solvent. This conclusion is deduced from observation of blue (abnormal) shift in Raman spectra of cytidine and 6-azaC microcrystals recrystallized from D2O solution. Both normal and abnormal shifts close to the experimentally observed were obtained in the calculated spectra of 6-azaC and cytidine. We assume that abnormal shifts may be caused by substitution of intramolecular H-bonds with D-bonds.

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Hamad, W. Y., i S. Eichhorn. "Deformation Micromechanics of Regenerated Cellulose Fibers Using Raman Spectroscopy". Journal of Engineering Materials and Technology 119, nr 3 (1.07.1997): 309–13. http://dx.doi.org/10.1115/1.2812262.

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It is demonstrated that Raman spectroscopy can be used to study the molecular deformation of TENCELR fibers. It is shown that the peak positions of the 895 cm−1 and 1095 cm−1 Raman bands shift to lower frequency upon the application of tensile stress or strain owing to the macroscopic deformation leading to direct stretching of the cellulose chains. Significant frequency shifts of 1.98 cm−1 and 3.26 cm−1 are obtained for the two Raman-sensitive peak positions, respectively, using the 632.8 nm laser radiation. It is found that the change in position of the Raman band is more closely related to molecular stress than strain, and that the molecular deformation processes for tencel resemble those for other conventional polymers (PET fibers) and high-performance fibers such as aromatic polyamides (aramids).

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Smith, David R., Jeffrey J. Field, David G. Winters, Scott R. Domingue, Frauke Rininsland, Daniel J. Kane, Jesse W. Wilson i Randy A. Bartels. "Phase noise limited frequency shift impulsive Raman spectroscopy". APL Photonics 6, nr 2 (1.02.2021): 026107. http://dx.doi.org/10.1063/5.0038624.

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Xue, Xiaobo, Corey Janisch, Yizhu Chen, Zhiwen Liu i Jingbiao Chen. "Low-frequency shift Raman spectroscopy using atomic filters". Optics Letters 41, nr 22 (15.11.2016): 5397. http://dx.doi.org/10.1364/ol.41.005397.

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Vickers, Thomas J., i Charles K. Mann. "Raman Shift Calibration of a Compact Multichannel Spectrometer". Applied Spectroscopy 53, nr 12 (grudzień 1999): 1617–22. http://dx.doi.org/10.1366/0003702991946082.

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Guo, Z. X., J. W. Ding, Y. Xiao i D. Y. Xing. "Raman frequency shift in oxygen-functionalized carbon nanotubes". Nanotechnology 18, nr 46 (12.10.2007): 465706. http://dx.doi.org/10.1088/0957-4484/18/46/465706.

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Salamon, D., P. Abbamonte, Ran Liu, M. V. Klein, W. C. Lee, D. M. Ginsberg, I. I. Tartakovskii i B. W. Veal. "Large-shift Raman scattering features in superconductingYBa2Cu3O6+x". Physical Review B 53, nr 2 (1.01.1996): 886–91. http://dx.doi.org/10.1103/physrevb.53.886.

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Chen, X. H., T. Takenobu, T. Muro, H. Fudo i Y. Iwasa. "Anomalous Raman shift in the ternary fullerides witht1gstates". Physical Review B 60, nr 17 (1.11.1999): 12462–66. http://dx.doi.org/10.1103/physrevb.60.12462.

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Al Mutoki, Sabah Mohammed Mlkat, Baydaa Abul Hassan Khalaf Al Ghzawi, Samir M. Abdul Amohsin i Emad Abbas Jaffar Al-Mulla. "Raman shift of silicon rubber-nano titania PMNC". Epitoanyag - Journal of Silicate Based and Composite Materials 69, nr 1 (2017): 20–23. http://dx.doi.org/10.14382/epitoanyag-jsbcm.2017.4.

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Bauer, Michael, Alexander M. Gigler, Andreas J. Huber, Rainer Hillenbrand i Robert W. Stark. "Temperature-depending Raman line-shift of silicon carbide". Journal of Raman Spectroscopy 40, nr 12 (11.05.2009): 1867–74. http://dx.doi.org/10.1002/jrs.2334.

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Kim, Jung Geun, i Jin Yu. "A study on the residual stress measurement methods on chemical vapor deposition diamond films". Journal of Materials Research 13, nr 11 (listopad 1998): 3027–33. http://dx.doi.org/10.1557/jmr.1998.0414.

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Diamond films were deposited on the p-type Si substrate with the hot filament chemical vapor deposition (HFCVD). Residual stresses in the films were measured in air by the laser curvature, the x-ray diffraction (XRD) dϕψ − sin2ψ, and the Raman peak shift methods. All of the measuring methods showed similar behaviors of residual stress that changed from a compressive to a tensile stress with increasing the film thickness. However, values of residual stresses obtained through the Raman and XRD methods were 3–4 times higher than those of the curvature method. These discrepancies involved the setting of materials constants of CVD diamond film, and determination of a peak shifting on the XRD and Raman method. In order to elucidate the disparity, we measured a Young's moduli of diamond films by using the sonic resonance method. In doing so, the Raman and XRD peak shift were calibrated by bending diamond/Si beams with diamond films by a known amount, with stress levels known a priori from the beam theory, and by monitoring the peak shifts simultaneously. Results of each measuring method showed well coincidental behaviors of residual stresses which have the stress range from −0.5 GPa to +0.7 GPa, and an intrinsic stress was caused about +0.7 GPa with tensile stress.

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Tereshchenko D. P., Smetanin S. N., Papashvili A. G., Gubina K. A., Kochukov Y. A., Solokhin S. A., Ershkov M. N. i in. "Spectrum multiplexing of multiwavelength picosecond oscillation of synchronously pumped Raman laser based on a Sr(MoO_4)-=SUB=-0.8-=/SUB=-(WO_4)-=SUB=-0.2-=/SUB=- crystal". Technical Physics 68, nr 4 (2023): 455. http://dx.doi.org/10.21883/tp.2023.04.55936.270-22.

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For the first time to our knowledge, a single-phase solid solution Sr(MoO_4)0.8(WO_4)0.2 was used as an active medium of a Raman laser. Using the high-intensity synchronous picosecond pumping satisfying the condition of phase capture of the parametric Raman interaction on the second vibrational mode made it possible to oscillate six components of Raman radiation with a combined frequency shift on the first (888 cm-1) and second (327 cm-1) vibrational modes in the wavelength range of 1194-1396 nm. Oscillation efficiency of the multiwavelength Raman laser radiation was as high as 10%. By detuning the Raman laser cavity length, the pulse shortening down to 6 ps for the Raman laser radiation components with the combined frequency shift was obtained, which is an order of magnitude shorter than the pumping pulse duration (64 ps). Keywords: stimulated Raman scattering, single-phase solid solution, vibrational mode, synchronous pumping.

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Aaron Falk, R., i Tram Pham. "Raman Temperature Measurements". EDFA Technical Articles 11, nr 4 (1.11.2009): 6–12. http://dx.doi.org/10.31399/asm.edfa.2009-4.p006.

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Abstract Virtually all semiconductor materials exhibit Raman scattering which results in a frequency shift in photon energy. In this article, the authors explain how they harness this mechanism to measure the temperature of submicron structures and thereby produce high-resolution temperature maps. They review the basic theory of Raman scattering and present application examples involving high-bandgap materials as well as silicon devices.

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Puppels, G. J., M. Grond i J. Greve. "Direct Imaging Raman Microscope Based on Tunable Wavelength Excitation and Narrow-Band Emission Detection". Applied Spectroscopy 47, nr 8 (sierpień 1993): 1256–67. http://dx.doi.org/10.1366/0003702934068017.

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A new type of imaging Raman microscope is described. First the advantages and disadvantages of the two possible approaches to Raman microscopy based on signal detection by means of a charge-coupled-device camera (i.e., direct imaging and image reconstruction) are discussed. Arguments are given to show that in most cases direct imaging is to be preferred over image reconstruction, because it provides the desired information in less time. In the direct imaging Raman microscope presented in this communication, detection of scattered light occurs in a narrow interval around a fixed wavelength. Selection of the Raman wavenumber shift at which an image is recorded is established by tuning the wavelength of the exciting laser light in such a way that the wavelength of the Raman scattered light with the desired Raman shift coincides with the detected wavelength. The microscope has been incorporated in a Raman microspectrometer in a way that enables easy switching between the imaging and the multichannel spectroscopy modes of operation. Bright field, fluorescence, and Raman microscopic images can be obtained.

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Olk, C. H., C. P. Beetz i J. Heremans. "Raman spectra during the electropolymerization of polypyrrole". Journal of Materials Research 3, nr 5 (październik 1988): 984–88. http://dx.doi.org/10.1557/jmr.1988.0984.

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In situ Raman spectra were taken, between 800 and 1200 cm−1, on films of polypyrrole during both the electrochemical growth and the reduction reactions. During the reduction reaction we observed a frequency shift of approximately 10 cm−1 of two in-plane vibrational modes. We attribute these shifts to the bond conjugational defects induced by doping and undoping of the polypyrrole films. A quantitative model for this phenomenon based on normal mode calculations is presented. The electrical conductivity and thermopower of polypyrrole doped with tetrafluoroborate and iron chloride ions is also reported for temperatures between 10 and 350K.

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40

Zhao, Xing-Zhong, K. A. Cherian, Rustum Roy i William B. White. "Downshift of Raman peak in diamond powders". Journal of Materials Research 13, nr 7 (lipiec 1998): 1974–76. http://dx.doi.org/10.1557/jmr.1998.0277.

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Results are presented on the influence of the size of diamond powders and the laser power on the main Raman line. These results show conclusively that there is a consistent and systematic, reversible, downshift with both decrease of powder size, and increase of power. The shift can be explained by local heating of about 500 °C in the extreme case. Its significance applies to interpretation of the alleged “downshifting” of the 1332 cm−1 line in all diamond research. In the future, the grain size, the thermal contact, and the beam power must be carefully monitored in reporting and interpreting any frequency shifts.

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Fountain, Augustus W., Thomas J. Vickers i Charles K. Mann. "Factors That Affect the Accuracy of Raman Shift Measurements on Multichannel Spectrometers". Applied Spectroscopy 52, nr 3 (marzec 1998): 462–68. http://dx.doi.org/10.1366/0003702981943699.

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Raman shift measurements have been made on cyclohexane, by using linear interpolation between bracketing neon line positions to establish Raman band wavelengths. Factors that affect the precision of these measurements have been examined in detail. These include change of slit width, grating line spacing, neon line intensity, distance of separation of neon lines, and effects of small grating movements. All these have some effect, but the last factor is particularly important. Techniques that give standard deviations of 0.03 cm−1 when measurements are made without moving the grating are degraded by about an order of magnitude when the grating is moved. This result is attributed to adventitious partitioning of signal power between adjacent detector elements. By deliberately moving the grating a small amount between otherwise replicate measurements, one can control this effect. Values for the Raman shifts for eleven cyclohexane bands, based on approximately 800 Raman spectra and an equal number of neon emission spectra, are presented. The values are compared with previous measurements. They are generally within the ±σ range of the earlier values, but the standard deviations of these results are about an order of magnitude smaller.

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42

Frank, Milan, Sergei Smetanin, Michal Jelínek, David Vyhlídal, Vladislav Shukshin, Lyudmila Ivleva, Elizaveta Dunaeva, Irina Voronina, Petr Zverev i Václav Kubeček. "Stimulated Raman Scattering in Alkali-Earth Tungstate and Molybdate Crystals at Both Stretching and Bending Raman Modes under Synchronous Picosecond Pumping with Multiple Pulse Shortening Down to 1 ps". Crystals 9, nr 3 (21.03.2019): 167. http://dx.doi.org/10.3390/cryst9030167.

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Comparative investigation of characteristics of spontaneous and stimulated Raman scattering (SRS) in different alkali-earth tungstate and molybdate crystals at both high and low frequency anionic group vibrations is presented. It has been found that, among these crystals, the SrMoO4 and SrWO4 crystals are the most perspective for SRS generation on both stretching and bending modes of internal anionic group vibrations with the strongest SRS pulse shortening under synchronous laser pumping because of not only highly intense stretching mode Raman line for efficient primary extra cavity long-shifted SRS conversion but also the widest bending mode Raman line for the strongest SRS pulse shortening down to the inverse width of the widest Raman line (~1 ps) at secondary intracavity short-shifted SRS conversion. The strongest 26-fold pump pulse shortening down to 1.4 ps at the Stokes component with the combined Raman shift in the synchronously pumped extra cavity SrMoO4 and SrWO4 Raman lasers has been demonstrated. It was found that synchronously pumped cascade SRS with combined Raman shift is more efficient in the SrWO4 crystal because the bending mode Raman line is more intense relative to the stretching mode Raman line than that in SrMoO4.

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Shu, Xiang Ping, Cheng Chen, Yi Ting He, Zhi Ren Qiu, Dong Sing Wuu i Zhe Chuan Feng. "Optical Probe in MgZnO Alloys with Varied Mg Ratios by Metalorganic Chemical Vapor Deposition". Advanced Materials Research 746 (sierpień 2013): 406–10. http://dx.doi.org/10.4028/www.scientific.net/amr.746.406.

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We present a study on five MgxZn1-xO samples with varied x (x = 0, 0.01, 0.06, 0.10 and 0.14), grown on sapphire substrate by Metalorganic Chemical Vapor Deposition (MOCVD). Combined photoluminescence (PL) and Raman scattering studies were carried out over a temperature range of 80K-470K, under the excitation of UV 325 nm. Temperature dependence of the PL for MgZnO with x = 0, 0.01 and 0.06 are shown. The resonance Raman longitudinal optical (LO) multiple modes are exhibited for MgZnO with x = 0.06, 0.10 and 0.14 over all temperature range. Raman shifts exhibit a quadratic dependence on temperature in the measured temperature range. These dependences can be calculated, based upon a model involving three-and four-phonon coupling. We attribute both the thermal expansion and four-phonon terms in the four-phonon anharmonic processes to describe the change of Raman shift with temperature.

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Chen, Cheng, Xiang Ping Shu, Hua Yang Sun, Zhi Ren Qiu, Ting Wei Liang, Li Wei Tu i Zhe Chuan Feng. "Temperature Dependence of Raman Scattering in M-Plane GaN with Varying III/V Ratios". Advanced Materials Research 602-604 (grudzień 2012): 1453–56. http://dx.doi.org/10.4028/www.scientific.net/amr.602-604.1453.

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The temperature dependence Raman scattering from m-plane GaN thin films grown on m-plane sapphire substrate by Molecular Beam Epitaxy (MBE) has been investigated. Three pieces of m-plane GaN films grown with different Ⅲ/Ⅴ ratios were studied by confocal micro-Raman spectrometer from -180 °C to 240 °C. Raman shift and the full width at half maximum (FWHM) were fitted by lorentzian line shape, which reveal the quality and compressive stress of sample. It’s obvious that the Raman shift and FWHM exhibit a quadratic dependence on temperature, and that the redshift of Raman peak position with increasing temperature should be due to anharmonic coupling to phonons of other branches, volume expansion or lattice dilation. Comparing the experiment data and calculated results, the three-phonons processes are dominant in the redshift of E1(LO) and E2(high).

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45

Subramaniam, S., M. J. Lance, C. J. Rawn, B. C. Chakoumakos i A. J. Rondinone. "Raman spectroscopic studies on structure I and structure IItrimethylene oxide hydrate". Canadian Journal of Physics 83, nr 9 (1.09.2005): 941–49. http://dx.doi.org/10.1139/p05-040.

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Raman spectra were collected from structure I (sI) and structure II (sII) trimethylene oxide (TMO) hydrates at various temperatures and used to assign the vibrational modes, investigate the ordering of TMO molecules inside the cage structure, and to determine possible interactions between the guest and the host lattice. Only Raman spectra from sI hydrate could be analyzed since the low concentration of TMO prevented sII peaks from being resolved. Comparison of the Raman spectra of liquid, solid, and enclathrated TMO (sI) showed Raman shifts to higher wave numbers for the enclathrated TMO; mainly among the ring modes. The ring and (or) skeletal modes around 930 cm1 and the asymmetric CH2 stretching mode around 2970 cm1, showed shifts greater than 10 cm1. These observed changes are interpreted on the basis of the "loose-cage tight-cage" model, which interprets the shift as arising from strain induced by the hydrate cage on the guest TMO molecules in the 62 cages. In addition, variable temperature Raman studies, in the temperatures ranging from 103 to 203 K, showed no evidence of ordering and (or) reorientation of host molecules. PACS No.: 78.30.-j

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Ham, William K., Steven W. Keller, James N. Michaels, Angelica M. Stacy, Dimitry Krillov, David T. Hodul i Ronald H. Fleming. "Partial substitution of 18O in YBa2Cu3O7: Investigations of inhomogeneities and their effect on Tc". Journal of Materials Research 4, nr 3 (czerwiec 1989): 504–14. http://dx.doi.org/10.1557/jmr.1989.0504.

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The possibility of site-selective substitution of 18O into YBa2Cu3O7 was explored. Samples containing various quantities of 18O were prepared by processing in 18O2 both at 950 °C and at 400 °C. The samples were characterized by secondary ion mass spectroscopy (SIMS), temperature programmed desorption (TPD) and reduction (TPR), Raman spectroscopy, and magnetization measurements. Measurements of the shifts in the Raman active modes with 18O substitution and of the ratios of 18O to 16O by TPD, TPR, and SIMS show that even for temperatures as low as 400 °C and times as short as 2 h. 18O is not substituted exclusively into the chain site (O1) in YBa2Cu3O7. In addition, there is no consistent variation in the shifts in Tc with the degree of substitution; therefore, the isotope effect for a sample with 100% 18O cannot be predicted by a linear extrapolation of data obtained for samples with partial 18O substitution. The mechanism of oxygen substitution, the difficulties of measuring the true magnitude of the oxygen isotope shift, and the meaning of the small isotope shift are discussed.

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Chrobak, Dariusz, Mateusz Dulski, Grzegorz Ziółkowski i Artur Chrobak. "Effect of the Indentation Load on the Raman Spectra of the InP Crystal". Materials 15, nr 15 (22.07.2022): 5098. http://dx.doi.org/10.3390/ma15155098.

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Nanoindentations and the Raman spectroscopy measurements were carried out on the (001) surface of undoped and S-doped InP crystal. The samples were indented with the maximum load ranging from 15 mN to 100 mN. The phase transition B3→B1 was not confirmed by spectroscopic experiments, indicating a plastic deformation mechanism governed by dislocations activity. Increasing the maximum indentation load shifts and the longitudinal and transverse optical Raman bands to lower frequencies reveals a reduction in the elastic energy stored in the plastic zone right below the indentation imprint. Mechanical experiments have shown that a shift in Raman bands occurs alongside the indentation size effect. Indeed, the hardness of undoped and S-doped InP crystal decreases as a function of the maximum indentation load.

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Li, Lianfu, Zengfeng Du, Xin Zhang, Shichuan Xi, Bing Wang, Zhendong Luan, Chao Lian i Jun Yan. "In Situ Raman Spectral Characteristics of Carbon Dioxide in a Deep-Sea Simulator of Extreme Environments Reaching 300 ℃ and 30 MPa". Applied Spectroscopy 72, nr 1 (3.08.2017): 48–59. http://dx.doi.org/10.1177/0003702817722820.

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Deep-sea carbon dioxide (CO2) plays a significant role in the global carbon cycle and directly affects the living environment of marine organisms. In situ Raman detection technology is an effective approach to study the behavior of deep-sea CO2. However, the Raman spectral characteristics of CO2 can be affected by the environment, thus restricting the phase identification and quantitative analysis of CO2. In order to study the Raman spectral characteristics of CO2 in extreme environments (up to 300 ℃ and 30 MPa), which cover most regions of hydrothermal vents and cold seeps around the world, a deep-sea extreme environment simulator was developed. The Raman spectra of CO2 in different phases were obtained with Raman insertion probe (RiP) system, which was also used in in situ Raman detection in the deep sea carried by remotely operated vehicle (ROV) “Faxian”. The Raman frequency shifts and bandwidths of gaseous, liquid, solid, and supercritical CO2 and the CO2–H2O system were determined with the simulator. In our experiments (0–300 ℃ and 0–30 MPa), the peak positions of the symmetric stretching modes of gaseous CO2, liquid CO2, and supercritical CO2 shift approximately 0.6 cm–1 (1387.8–1388.4 cm–1), 0.7 cm–1 (1385.5–1386.2 cm–1), and 2.5 cm–1 (1385.7–1388.2 cm–1), and those of the bending modes shift about 1.0 cm–1 (1284.7–1285.7 cm–1), 1.9 cm–1 (1280.1–1282.0 cm–1), and 4.4 cm–1 (1281.0–1285.4 cm–1), respectively. The Raman spectral characteristics of the CO2–H2O system were also studied under the same conditions. The peak positions of dissolved CO2 varied approximately 4.5 cm–1 (1282.5–1287.0 cm–1) and 2.4 cm–1 (1274.4–1276.8 cm–1) for each peak. In comparison with our experiment results, the phases of CO2 in extreme conditions (0–3000 m and 0–300 ℃) can be identified with the Raman spectra collected in situ. This qualitative research on CO2 can also support the further quantitative analysis of dissolved CO2 in extreme conditions.

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Palla, Mirkó, Wenjing Guo, Shundi Shi, Zengmin Li, Jian Wu, Steffen Jockusch, Cheng Guo, James J. Russo, Nicholas J. Turro i Jingyue Ju. "DNA sequencing by synthesis using 3′-O-azidomethyl nucleotide reversible terminators and surface-enhanced Raman spectroscopic detection". RSC Adv. 4, nr 90 (2014): 49342–46. http://dx.doi.org/10.1039/c4ra08398a.

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DNA sequencing using surface enhanced Raman spectroscopy for the detection of the unique Raman shift of the azido group was demonstrated using 3′-O-azidomethyl nucleotide reversible terminators in polymerase reaction.

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Wang, Cong, Xing Yu Zhang, Qing Pu Wang, Xiao Han Chen, Zhen Hua Cong, Zhao Jun Liu, Hui Hua Xu i Jian Li He. "A Brief Study on Silicon Crystal Materials as a Mid-IR Raman Amplifier". Advanced Materials Research 531 (czerwiec 2012): 185–88. http://dx.doi.org/10.4028/www.scientific.net/amr.531.185.

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We consider a bulk silicon crystal as a Mid-IR Raman amplifier and study its Raman amplification. A Raman amplifier is established when an intense pump laser pulse and a Raman laser pulse pass through one silicon simultaneously, with good spatial and temporal overlap. Considering the situation of pumping wavelength at 2.94 μm achievable by using an Er:YAG laser and Raman laser wavelength at 3.47 μm with the 521 cm-1 Raman shift, the properties of the output amplified Raman laser are investigated by numerically solving the coupled transfer equations.

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