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Artículos de revistas sobre el tema "Vibrational Raman Modes"

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Autor: Grafiati

Publicado: 6 de septiembre de 2023

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1

Jumeau, Richard, Patrice Bourson, Michel Ferriol, François Lahure, Marc Ponçot y Abdesselam Dahoun. "Identification of LDPE Grades Focusing on Specific CH2 Raman Vibration Modes". International Journal of Spectroscopy 2013 (15 de abril de 2013): 1–6. http://dx.doi.org/10.1155/2013/720598.

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The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.

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2

Okamoto, Hiromi, Takakazu Nakabayashi y Mitsuo Tasumi. "Picosecond Anti-Stokes Raman Excitation Profiles as a Method for Investigating Vibrationally Excited Transients". Laser Chemistry 19, n.º 1-4 (1 de enero de 1999): 335–41. http://dx.doi.org/10.1155/1999/21312.

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A method for estimating vibrational quantum numbers of vibrationally excited transients in solution is proposed. In this method, we calculate anti-Stokes Raman excitation profiles (REPs) which are characteristic of the initial vibrational states involved in the Raman process, and compare them with observed anti-Stokes intensities. We have applied this method to vibrationally hot molecules of canthaxanthin in the So state and those of trans-stilbene in the S1 state. For canthaxanthin, it has been found that the vibrationally excited transients are for the most part on the ν=1 level of the C═C stretching mode, and that excess vibrational energy is statistically distributed among all intramolecular vibrational modes. As for S1 stilbene, vibrational transients are shown to be mostly on the ν=1 level for two vibrational modes examined, while the excess vibrational energy is probably localised on the olefinic C═C stretching mode.

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3

Fang, S. L., L. Grigorian, P. C. Eklund, G. Dresselhaus, M. S. Dresselhaus, H. Kawaji y S. Yamanaka. "Raman scattering from vibrational modes inSi46clathrates". Physical Review B 57, n.º 13 (1 de abril de 1998): 7686–93. http://dx.doi.org/10.1103/physrevb.57.7686.

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4

Shakoor, Abdul, Fayyaz Hussain, Najmul Hassan, Abdul Majid, Muhammad Tariq Bhatti y Hassan Siddique. "A density functional theory study of Raman modes of cadmium hexathiohypodiphosphate (CdPS3)". Materials Science-Poland 33, n.º 2 (1 de junio de 2015): 286–91. http://dx.doi.org/10.1515/msp-2015-0041.

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AbstractRaman scattering investigations based on density functional theory (DFT) calculations were performed to explore the vibrational modes of a cadmium hexathiohypodiphosphate CdPS3 single crystal. The calculations were performed to obtain the Raman spectra for the cadmium hexathiohypodiphosphate atoms to study the size dependence. Several vibrational modes indicating stretching and bending features related to Cd, S and P atoms were observed. Modifications of the frequency and intensity of different Raman modes with an increase in the number of atoms in CdPS3 were discussed in detail. Hydrogen atoms were added in order to make the closed shell configuration and saturate the CdPS3 as per the requisite for calculating the Raman spectra. This produced some additional modes of vibration related to hydrogen atoms. Band gap and formation energy were also calculated. The results generated are found to be in close agreement with the experimental values.

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5

Islam, Md Mahfujul y Fredric Datchi. "Polarized Raman Spectra of α Quartz". International Letters of Chemistry, Physics and Astronomy 56 (julio de 2015): 91–98. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.56.91.

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The purpose of this experiment was to observe the Raman shift to assign the symmetry character of the obtained vibrational modes of α-quartz (which has 9 atom per unit cell) using the selection rules for Raman Effect. We observed the Raman spectra varying the polarization of the incoming beam and the orientation of the crystal. And we used monochromatic radiation of argon laser of wavelength 540 nm for our Raman spectroscopy. We observed the intensity of light rotating the polarizer to vertical position from its horizontal position with respect to the plane of the optical table where the laser is placed and measured the Raman spectra over an energy from 50 to 1250 cm-1 using the laser power of 1W and an acquisition time of 10 sec. averaging over 2 acquisitions. From our experiment we can see that here is 4symmetry for A1 which is predicted on our vibrational modes. However for E symmetry mode we have observed 14 vibrational modes but as E is doubly degenerate there should be 16 vibrational modes on the Raman active modes in the α quartz, as we can see that there are two vibration missing ,it happens may be due to noise on the surroundings. We got different peaks due to the different intensities and the different orientation of the laser beam hitting the sample on different angle. The different intensities of the peaks for the different orientation might be due to the laser beam hitting the samples at different angles due to differences in the orientation of the surfaces. We also found that the biggest amount of the re-radiated light was vibrating horizontally, i.e. in the same direction as the laser beam hitting the sample.

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6

Islam, Md Mahfujul y Fredric Datchi. "Polarized Raman Spectra of α Quartz". International Letters of Chemistry, Physics and Astronomy 56 (21 de julio de 2015): 91–98. http://dx.doi.org/10.56431/p-k754hp.

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The purpose of this experiment was to observe the Raman shift to assign the symmetry character of the obtained vibrational modes of α-quartz (which has 9 atom per unit cell) using the selection rules for Raman Effect. We observed the Raman spectra varying the polarization of the incoming beam and the orientation of the crystal. And we used monochromatic radiation of argon laser of wavelength 540 nm for our Raman spectroscopy. We observed the intensity of light rotating the polarizer to vertical position from its horizontal position with respect to the plane of the optical table where the laser is placed and measured the Raman spectra over an energy from 50 to 1250 cm-1 using the laser power of 1W and an acquisition time of 10 sec. averaging over 2 acquisitions. From our experiment we can see that here is 4symmetry for A1 which is predicted on our vibrational modes. However for E symmetry mode we have observed 14 vibrational modes but as E is doubly degenerate there should be 16 vibrational modes on the Raman active modes in the α quartz, as we can see that there are two vibration missing ,it happens may be due to noise on the surroundings. We got different peaks due to the different intensities and the different orientation of the laser beam hitting the sample on different angle. The different intensities of the peaks for the different orientation might be due to the laser beam hitting the samples at different angles due to differences in the orientation of the surfaces. We also found that the biggest amount of the re-radiated light was vibrating horizontally, i.e. in the same direction as the laser beam hitting the sample.

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7

Nakabayashi, Takakazu, Hiromi Okamoto y Mitsuo Tasumi. "Pump- And Probe-Wavelength Dependencies of Picosecond Anti-Stokes Raman Spectrum of Trans-Stilbene in the S1 State". Laser Chemistry 19, n.º 1-4 (1 de enero de 1999): 75–78. http://dx.doi.org/10.1155/1999/10475.

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Vibrational relaxation dynamics of trans-stilbene in the S1 state immediately after photoexcitation is studied by picosecond time-resolved anti-Stokes Raman spectroscopy with several pump and probe wavelengths. Pump-wavelength dependence of the anti- Stokes spectrum indicates that, when pump photons with high excess energy (≈5200cm-1) are used, the anti-Stokes Raman bands at 0 ps delay time arise from vibrationally excited transients with excess vibrational energy not thermally distributed in the molecule. Probe-wavelength dependence suggests that the vibrationally excited transients at 0 ps are mostly on the lowest excited vibrational levels, as far as the olefinic C═C stretching and the C–Ph stretching modes are concerned. The vibrational relaxation process of S1trans-stilbene is discussed on the basis of the observed results.

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8

Коrnienko, N. E. y O. L. Pavlenko. "Multiple Fermi Resonances in Liquid Benzene". Ukrainian Journal of Physics 65, n.º 6 (9 de junio de 2020): 480. http://dx.doi.org/10.15407/ujpe65.6.480.

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A number of coupled Fermi vibrational resonances (FRs) in liquid benzene from a multitude of them are systematically studied. The spectral structure of the vibrational bands in the IR absorption and Raman scattering spectra are determined by their numerical decomposition into individual components. The complication of vibrational resonances with an increase in their order is due to the overlapping of FRs and the appearance of additional resonant vibrational modes. To clarify the identification of the vibrations of the benzene FR v1+v6, v8 and the correction of the frequencies of a number of inactive vibrations, including v13(E1u), the experimental results are compared to the data obtained by quantum-chemical calculations. With regard for the collective-wave properties of vibrational modes in the benzene liquid state, we propose a new content of the analysis of FRs. It should include the study of 1) the intensity changes for various spectral components in the IR absorption and Raman scattering for FR vibrational bands of various orders, 2) half-widths δv of the bands, and 3) anharmonic shifts ΔvA for various components in the vibrational bands of FRs.

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9

Vaithianathan, V., R. Kesavamoorthy, C. V. Kannan, P. Santhanaraghavan y P. Ramasamy. "Raman study of gaseous bubble inclusions in bismuth germanate and bismuth germanium silicon oxide single crystals". Journal of Materials Research 18, n.º 4 (abril de 2003): 762–67. http://dx.doi.org/10.1557/jmr.2003.0105.

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Gaseous bubble inclusions in bismuth germanate (BGO) and bismuth germanium silicon oxide (BGSO) crystals were studied by means of Raman spectroscopy at room temperature. Their Raman spectra in the range from 60 to 70 cm−1 showed three peaks for the rotational Raman modes of O2 and N2. Vibrational Raman modes of O2 and N2 were also recorded for BGO and BGSO crystals. It was found that all the rotational and vibrational modes were blue shifted from those of free molecules due to the hydrostatic pressure in the bubbles. Internal pressure in the bubbles was estimated from the rotational and vibrational Raman mode frequencies. O2 gas pressure in the bubble was estimated as 140 GPa, and N2 gas pressure, as 31 GPa. The pressure coefficient of the vibrational mode frequency of O2 (0.368 cm−1/GPa for O2 vibrational mode of 1580 cm−1) and N2 (0.322 cm−1/GPa for N2 vibrational mode of 2331 cm−1) was also obtained from the blue shift and the calculated bubble pressure.

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10

Srinivasan, S. y V. Renganayaki. "Computational Studies of Vibration Spectra and Thermodynamic Properties of Metformin Using HF, DFT Methods". Material Science Research India 8, n.º 1 (25 de junio de 2011): 165–72. http://dx.doi.org/10.13005/msri/080124.

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The molecular vibrations of metformin, one of the important anti-diabetic drugs to treat Non Insulin Dependent Diabetes Mellitus (NIDDM) have been investigated at room temperature by Fourier transform infrared (FTIR) and Fourier transform Raman (FTR) spectroscopies. The solid phase FTIR and FT-Raman spectra of the title compound have been recorded in the regions 4000-400 and 3500-250 cm-1. A satisfactory band assignment has been made on the fundamental modes of vibration. Employing the ab - initio Hatree –Fock (HF) and Density Function Theory (DFT) methods, the theoretical vibrational frequencies and geometry parameters like bond lengths, bond angles etc have been calculated and compared with the experimental values. HF and DFT calculations were performed using the standard B3LYP/6-31G** method and basis set combination. Optimized geometries were obtained using the global optimization procedure. Theoretical investigations of harmonic vibrational frequencies and thermodynamic properties viz. the zero point vibrational energy (ZPVE), entropy, heat capacity have been carried out. It has been found that both methods gave consistent data for geometric parameters, but DFT yielded vibrational frequencies much closer to the experimental values.

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11

Tarrago Velez, Santiago, Vivishek Sudhir, Nicolas Sangouard y Christophe Galland. "Bell correlations between light and vibration at ambient conditions". Science Advances 6, n.º 51 (diciembre de 2020): eabb0260. http://dx.doi.org/10.1126/sciadv.abb0260.

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Time-resolved Raman spectroscopy techniques offer various ways to study the dynamics of molecular vibrations in liquids or gases and optical phonons in crystals. While these techniques give access to the coherence time of the vibrational modes, they are not able to reveal the fragile quantum correlations that are spontaneously created between light and vibration during the Raman interaction. Here, we present a scheme leveraging universal properties of spontaneous Raman scattering to demonstrate Bell correlations between light and a collective molecular vibration. We measure the decay of these hybrid photon-phonon Bell correlations with sub-picosecond time resolution and find that they survive over several hundred oscillations at ambient conditions. Our method offers a universal approach to generate entanglement between light and molecular vibrations. Moreover, our results pave the way for the study of quantum correlations in more complex solid-state and molecular systems in their natural state.

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12

Ristić, D., Mile Ivanda, K. Furić, M. Montagna, Maurizio Ferrari, A. Chiasera y Yoann Jestin. "Raman Scattering on the l=2 Spheroidal Mode of Spherical Nanoparticles". Advances in Science and Technology 55 (septiembre de 2008): 132–37. http://dx.doi.org/10.4028/www.scientific.net/ast.55.132.

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The Raman light to vibrations coupling coefficients C(ν) of quadrupolar and symmetrical vibrational modes of spherical nanoparticles embedded in a matrix are calculated. In contrast to the symmetrical mode, the C(ν) of the quadrupolar modes consists of the longitudinal and transversal sound velocity contributions. It is shown, that depending on the ratio of longitudinal and transverse sound velocity, these two contributions can interfere constructively or destructively resulting in enhancing or vanishing of some radial modes. Different peaks in the C(ν) spectrum were attributed to transverse and longitudinal spheroidal modes and the longitudinal spheroidal modes were found to have a higher Raman intensity than the transverse modes. The theoretical model was tested on a sample of HfO2 nanoparticles in a silica matrix.

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13

Batyrev, I. G. y R. C. Sausa. "Calculations and Experimental Studies of TAGzT under High Pressure". MRS Advances 1, n.º 17 (2016): 1227–32. http://dx.doi.org/10.1557/adv.2016.228.

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ABSTRACTWe studied TAGzT theoretically using density functional perturbation theory within the plane-wave-pseudo-potential formalism and experimentally by Raman and IR spectroscopy at ambient and high pressure. The modeled spectra predict reasonably well the experimental spectra at ambient pressure and the Raman vibrational modes at pressures up to 25 GPa. We report the effects of pressure on volume, Raman and IR vibrational modes, and charge distribution of TAGzT.

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14

Fayyadh, Hamid A., Dhaidan Kh Kafi y Ahmad Aziz Darweesh. "Study IR- Raman Spectra properties of Aluminium Phosphide Diamondoids Nanostructures via DFT". Al-Mustansiriyah Journal of Science 33, n.º 4 (30 de diciembre de 2022): 131–35. http://dx.doi.org/10.23851/mjs.v33i4.1182.

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Density Functional Theory has been utilized to investigate the electronic and structural characteristics of Aluminium phosphide (AlP). The exchange-correlation potential was calculated using the Generalized Gradient Approximation. The structural, electronic and vibrational features of AlP diamondoids and nanocrystals were investigated using Density Functional Theory at the PBE/6-31(d) level, which included polarization functions. Vibrational modes have been optimized concerning IR intensity, force constants, and lowered masses. In this study there are two components to the vibrational force constant for AlP diamondoids. The first one is distinguished by a reduced mass that is greater than 1 amu and consists primarily of Al-P vibrations that are positioned roughly between 0 and 231 cm-1. The second component has a decreased mass very near to 1 amu and is in the 1228–2400 cm–1 range. It is entirely made up of hydrogen vibrational modes. AlP diamondoids were evaluated with the results of experimental bulk in terms of molecular size-related changes in allocated vibrational frequencies.

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15

Cao, Jing-Wen, Jia-Yi Chen, Xiao-Ling Qin, Xu-Liang Zhu, Lu Jiang, Yue Gu, Xu-Hao Yu y Peng Zhang. "DFT Investigations of the Vibrational Spectra and Translational Modes of Ice II". Molecules 24, n.º 17 (28 de agosto de 2019): 3135. http://dx.doi.org/10.3390/molecules24173135.

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The vibrational spectrum of ice II was investigated using the CASTEP code based on first-principles density functional theory (DFT). Based on good agreement with inelastic neutron scattering (INS), infrared (IR), and Raman experimental data, we discuss the translation, libration, bending, and stretching band using normal modes analysis method. In the translation band, we found that the four-bond and two-bond molecular vibration modes constitute three main peaks in accordance with INS ranging from 117 to 318 cm−1. We also discovered that the lower frequencies are cluster vibrations that may overlap with acoustic phonons. Whale et al. found in ice XV that some intramolecular vibrational modes include many isolated-molecule stretches of only one O–H bond, whereas the other O–H bond does not vibrate. This phenomenon is very common in ice II, and we attribute it to local tetrahedral deformation. The pathway of combining normal mode analysis with experimental spectra leads to scientific assignments.

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16

Heidari, A. y C. Brown. "Vibrational spectroscopic study of intensities and shifts of symmetric vibration modes of ozone diluted by cumene". International Journal of Advanced Chemistry 4, n.º 1 (7 de mayo de 2016): 5. http://dx.doi.org/10.14419/ijac.v4i1.6080.

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In the current research, ATR–FTIR and FT–Raman spectroscopies was used to investigate the effect of concentration on IR and Raman intensities and shifts of symmetric vibration modes of Ozone diluted by Cumene. The symmetric vibration mode of Ozone was observed at IR and Raman shifts of 850 and 975 cm-1, respectively. By reducing the concentration of Ozone, its intensity also was reduced and the symmetric vibration mode of Cumene was observed at IR and Raman shifts of 1050 and 1185 cm-1, respectively. The concentration has not influence on IR and Raman shifts of vibration modes. The experimental results were confirmed the linear dependency of IR and Raman intensities to the concentration of sample.Ozone molecule (left illustration) and Cumene molecule (right illustration) (Santiago-López et al. 2010; Guevara-Guzmán et al. 2009; Pereyra-Muñoz et al. 2006; Foucaud et al. 2006; Elsayed 2001; van Hoof et al. 1997; Chrostowski et al. 1983; Boehme et al. 1992; Catalá et al. 2013; Balvers et al. 1992; Marker et al. 1986).

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17

Vijayasekhar, J. "Resonance Raman Spectra of Erythrocytes: Vibron Model". Oriental Journal of Chemistry 34, n.º 5 (15 de octubre de 2018): 2671–72. http://dx.doi.org/10.13005/ojc/340561.

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In this paper, vibrational spectra (infrared and Raman) of oxygenated and deoxynated functional erythrocytes are calculated using theoretical method “Vibron model” in the one-dimensional [U(2)] framework. The determined vibrational modes by Vibron model are compared with experimental data. It has been observed that results from the theoretical model reveal near to the exact, reliable with the experimental data.

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18

Ge, Meilan, Yuye Wang, Junfeng Zhu, Bin Wu, Degang Xu y Jianquan Yao. "Low-Frequency Vibrational Spectroscopy Characteristic of Pharmaceutical Carbamazepine Co-Crystals with Nicotinamide and Saccharin". Sensors 22, n.º 11 (27 de mayo de 2022): 4053. http://dx.doi.org/10.3390/s22114053.

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The pharmaceutical co-crystal has attracted increasing interest due to the improvement of physicochemical properties of active pharmaceutical ingredients. The characterization of pharmaceutical co-crystal is an integral part of the pharmaceutical field. In this paper, the low-frequency vibrational properties for carbamazepine co-crystals with nicotinamide and saccharin (CBZ-NIC and CBZ-SAC) have been characterized by combining the THz spectroscopy with low-wavenumber Raman spectroscopy. The experiment results show that, compared with the individual constituents, CBZ-NIC and CBZ-SAC co-crystals not only have different characteristic absorption peaks in the 0.3-2.5 THz region, but also have significant low-wavenumber Raman characteristic peaks in 0–100 cm−1. Density functional theory was performed to simulate the terahertz and low-wavenumber Raman spectra of the two co-crystals, where the calculation agreed well with the measured vibrational peak positions. The vibrational modes of CBZ-NIC and CBZ-SAC co-crystals were assigned through comparing theoretical results with the experimental spectra. Meanwhile, the low-frequency infrared and/or Raman active of characteristic peaks for such co-crystals were discussed. The results indicate the combination of THz spectroscopy and low-wavenumber Raman spectroscopy can provide more comprehensive low-frequency vibrational information for pharmaceutical co-crystals, such as collective vibration and skeleton vibration, which could play an important role in pharmaceutical science.

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19

Michaelian, K. H. "The Raman spectrum of kaolinite #9 at 21°C". Canadian Journal of Chemistry 64, n.º 2 (1 de febrero de 1986): 285–94. http://dx.doi.org/10.1139/v86-048.

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The Raman spectrum of kaolinite #9, a layer silicate of composition Al2Si2O5(OH)4 from Mesa Alta, New Mexico, USA, is reported and compared to previously published Raman and infrared spectra, as well as calculated lattice vibration frequencies, of other kaolinite samples. In the OH stretching region, a Raman band is observed at 3684 cm−1, a frequency which is generally unknown in infrared spectra of kaolinite. The two most likely origins of this band are (a) uncoupled inner-surface hydroxyl stretching, and (b) transverse/longitudinal splitting involving the 3695 cm−1 band, which occurs in both Raman and infrared spectra of kaolinite. The existing data do not conclusively show which of these explanations is correct. In the lattice vibration region, most of the observed Raman bands of kaolinite #9 have been tentatively assigned by comparison with published frequency calculations and existing assignments of infrared spectra of various kaolinites. The descriptions of many of the vibrational modes are approximate, partly because extensive mixing of vibrations makes a simple description of them impossible.

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20

Wang, Qiqi, Jiadan Xue, Zhi Hong y Yong Du. "Pharmaceutical Cocrystal Formation of Pyrazinamide with 3-Hydroxybenzoic Acid: A Terahertz and Raman Vibrational Spectroscopies Study". Molecules 24, n.º 3 (30 de enero de 2019): 488. http://dx.doi.org/10.3390/molecules24030488.

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Vibrational modes of pyrazinamide (PZA), 3-hydroxybenzoic acid (3-hBA), and their cocrystal were characterized using terahertz time-domain (THz-TDS) and Raman vibrational spectroscopic techniques. In experimental THz spectra, the cocrystal has characteristic absorption bands at around 0.81, 1.47, and 1.61 THz, respectively, meanwhile the raw materials are absolutely different in this region. Raman spectra also show similar results about differences between the cocrystal and corresponding starting parent materials. Density functional theory (DFT) was used to simulate both optimized structures and vibrational modes of the cocrystal formed between PZA and 3-hBA. The vibrational modes of such cocrystal are assigned through comparing the simulation DFT frequency results with experimental vibrational spectra. The calculation of the theoretical THz spectrum shows that the hydrogen bonding effect established between H11–N12–H13 and the carboxyl group -COOH makes contributions to the formation of absorption peaks in 0.49, 0.62, 0.83, and 1.61 THz, which agrees pretty well with experimental results. The theoretical Raman result also matches well with experimental observations. The results provide a fundamental benchmark for the study of pharmaceutical cocrystal formation and also inter-molecular hydrogen bonding interactions between active pharmaceutical ingredients and various cocrystal coformers based on Raman and terahertz vibrational spectroscopic techniques combined with theoretical simulations.

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21

Джахангирли, З. А., Р. Г. Велиев, И. А. Мамедова, З. И. Бадалова, Д. А. Мамедов, Н. Т. Мамедов y Н. А. Абдуллаев. "Ab initio и экспериментальное исследование колебательных свойств кристаллов TlFeS-=SUB=-2-=/SUB=- и TlFeSe-=SUB=-2-=/SUB=-". Физика твердого тела 63, n.º 10 (2021): 1637. http://dx.doi.org/10.21883/ftt.2021.10.51416.099.

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The lattice vibrational properties of TlFeS2 and TlFeSe2 crystals have been studied experimentally using Raman scattering (RS) and infrared reflection (IR) light, as well as theoretically using density functional theory (DFT). The complete vibrational representation, based on the analysis of the factor site symmetry, contains 12 active Raman modes and 9 IR active modes. 6 RS active and 3 IR active modes of them for TlFeS2, and 4 RS active and 3 IR active modes for TlFeSe2 were experimentally detected and identified.

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22

Zhang, Yao, Ben Yang, Atif Ghafoor, Yang Zhang, Yu-Fan Zhang, Rui-Pu Wang, Jin-Long Yang, Yi Luo, Zhen-Chao Dong y J. G. Hou. "Visually constructing the chemical structure of a single molecule by scanning Raman picoscopy". National Science Review 6, n.º 6 (1 de noviembre de 2019): 1169–75. http://dx.doi.org/10.1093/nsr/nwz180.

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Abstract The strong spatial confinement of a nanocavity plasmonic field has made it possible to visualize the inner structure of a single molecule and even to distinguish its vibrational modes in real space. With such ever-improved spatial resolution, it is anticipated that full vibrational imaging of a molecule could be achieved to reveal molecular structural details. Here we demonstrate full Raman images of individual vibrational modes at the ångström level for a single Mg-porphine molecule, revealing distinct characteristics of each vibrational mode in real space. Furthermore, by exploiting the underlying interference effect and Raman fingerprint database, we propose a new methodology for structural determination, which we have called ‘scanning Raman picoscopy’, to show how such ultrahigh-resolution spectromicroscopic vibrational images can be used to visually assemble the chemical structure of a single molecule through a simple Lego-like building process.

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23

Wang, Chun-Hai, Xi-Ping Jing, Wei Feng y Jing Lu. "Assignment of Raman-active vibrational modes of MgTiO3". Journal of Applied Physics 104, n.º 3 (agosto de 2008): 034112. http://dx.doi.org/10.1063/1.2966717.

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24

Peterson, D. L., A. Petrou, W. Giriat, A. K. Ramdas y S. Rodriguez. "Raman scattering from the vibrational modes inZn1−xMnxTe". Physical Review B 33, n.º 2 (15 de enero de 1986): 1160–65. http://dx.doi.org/10.1103/physrevb.33.1160.

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25

Hur, Jaewoong y Steven J. Stuart. "Raman intensity and vibrational modes of armchair CNTs". Chemical Physics Letters 679 (julio de 2017): 45–51. http://dx.doi.org/10.1016/j.cplett.2017.04.078.

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26

Wang, Jyhpyng, Kuei-Hsien Chen y Eric Mazur. "Raman spectroscopy of infrared multiphoton excited molecules". Laser Chemistry 8, n.º 2-4 (1 de enero de 1988): 97–122. http://dx.doi.org/10.1155/lc.8.97.

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This paper presents an overview of data obtained on the intramolecular vibrational energy distribution in infrared multiphoton excited CF2HCl, CF2Cl2, SF6 and CH3CHF2. All but CF2HCl show collisionless changes in the intensity of the spontaneous Raman signals after excitation, indicating that the excitation alters the population in the Raman active modes. A comparison of the spectrally integrated intensities of the Raman signals yields information on the distribution of vibrational energy over the modes of the molecule. The results for CF2Cl2 show a nonthermal distribution of energy after the excitation.

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27

Lazarevska, Sofija y Petre Makreski. "Insights into the infrared and Raman spectra of fresh and lyophilized royal jelly and protein degradation IR spectroscopy study during heating". Macedonian Journal of Chemistry and Chemical Engineering 34, n.º 1 (5 de mayo de 2015): 87. http://dx.doi.org/10.20450/mjcce.2015.669.

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<p> In terms of chemical composition, a honeybee secretion known as royal jelly (RJ) is very complex product containing water, proteins, carbohydrates, lipids, mineral salts and small amounts of polyphenols, vitamins and enzymes. Despite its chemical diversity, the bands originating from vibrational modes of the present proteins were successfully assigned in 1800–1200 cm<sup>–1</sup> (Raman and IR) region where the interference of bands from other vibrational species is not substantial. The protein bands were attributed to amide I, amide II and amide III modes and their intensities, additionally, enabled to determine the protein secondary structures. The remaining bands up to 4000 cm<sup>–1</sup> were attributed to other group vibrations whereas the region below 1200 cm<sup>–1 </sup>comprises bands from complex interacting modes within the major RJ components that can not be unequivocally attributed to distinct modes. The work also represents a pioneering effort to collect and interpret the Raman spectrum of fresh and lyophilized RJ samples and to correlate and describe the observed similarities/differences between IR and Raman spectra.</p>

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28

Qu, Xinhua, Eunah Lee, Gu-Sheng Yu, Teresa B. Freedman y Laurence A. Nafie. "Quantitative Comparison of Experimental Infrared and Raman Optical Activity Spectra". Applied Spectroscopy 50, n.º 5 (mayo de 1996): 649–57. http://dx.doi.org/10.1366/0003702963905970.

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Infrared vibrational circular dichroism (VCD) and vibrational Raman optical activity (ROA) have been measured and compared quantitatively over the frequency range from 835 to 1345 cm−1 for trans-pinane, cis-pinane, α-pinene, and β-pinene. For these molecules in this region of spectral overlap between VCD and ROA, the average ratio of VCD or ROA to its parent vibrational intensity favors ROA by a factor of two to three. Several vibrational modes in each molecule yield both large VCD and large ROA, while several other modes show little propensity toward significant VCD or ROA intensity. Beyond this general property of a few strongly chiral and strongly achiral vibrational modes, little additional correlation between VCD and ROA intensity is found. This quantitative compilation of VCD, infrared, ROA, and Raman intensities provides an experimental basis for computational intensity studies of VCD, ROA, and their theoretical comparison.

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29

Milekhin, Alexander G., Olga Cherkasova, Sergei A. Kuznetsov, Ilya A. Milekhin, Ekatherina E. Rodyakina, Alexander V. Latyshev, Sreetama Banerjee, Georgeta Salvan y Dietrich R. T. Zahn. "Nanoantenna-assisted plasmonic enhancement of IR absorption of vibrational modes of organic molecules". Beilstein Journal of Nanotechnology 8 (3 de mayo de 2017): 975–81. http://dx.doi.org/10.3762/bjnano.8.99.

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Nanoantenna-assisted plasmonic enhancement of IR absorption and Raman scattering was employed for studying the vibrational modes in organic molecules. Ultrathin cobalt phthalocyanine films (3 nm) were deposited on Au nanoantenna arrays with specified structural parameters. The deposited organic films reveal the enhancement of both Raman scattering and IR absorption vibrational modes. To extend the possibility of implementing surface-enhanced infrared absorption (SEIRA) for biological applications, the detection and analysis of the steroid hormone cortisol was demonstrated.

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30

Smith, PW y R. Stranger. "Vibrational-Spectra of Salts of the Type-AI3[Mo2X9] with X = Cl, Br, I". Australian Journal of Chemistry 39, n.º 8 (1986): 1269. http://dx.doi.org/10.1071/ch9861269.

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The far-infrared and Raman spectra of a series of alkali, ammonium and alkylammonium salts of Mo2X93- (X = Cl , Br, I) have been measured. All observed infrared-active vibrations, including lattice modes, together with certain Raman-active modes, have been assigned for the alkali salts of Mo2Cl93- on the basis of the D6h unit cell symmetry which applies. The vibrational assignments for the corresponding bromide and iodide complexes follow in the same relative order as those of Mo2Cl93-. The splitting of degenerate modes for certain alkylammonium salts of Mo2Cl93- has been interpreted on the basis of C2v symmetry applicable to these particular salts. By correlating the spectral changes observed with variation of the cation, it has been possible to distinguish the bridging-halogen deformation modes from neighbouring lattice modes.

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31

Ragam, M., N. Sankar y K. Ramachandran. "Localized Vibrational Mode in Manganese-Doped Zinc Sulphide and Cadmium Sulphide Nanoparticles". Defect and Diffusion Forum 318 (julio de 2011): 11–21. http://dx.doi.org/10.4028/www.scientific.net/ddf.318.11.

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Defect modes in ZnS:Mn and CdS:Mn nanoparticles are investigated by means of Fourier transform infrared spectroscopy and the Raman technique for local vibrational modes (LVM), and the observed modes are explained theoretically by using a molecular model.

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32

Kharintsev, Sergey S., Almaz R. Gazizov, Myakzyum Kh Salakhov y Sergei G. Kazarian. "Near-field depolarization of tip-enhanced Raman scattering by single azo-chromophores". Physical Chemistry Chemical Physics 20, n.º 37 (2018): 24088–98. http://dx.doi.org/10.1039/c8cp04887h.

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33

Zhang, Kai, Peng Zhang, Ze-Ren Wang, Xu-Liang Zhu, Ying-Bo Lu, Cheng-Bo Guan y Yanhui Li. "DFT Simulations of the Vibrational Spectrum and Hydrogen Bonds of Ice XIV". Molecules 23, n.º 7 (19 de julio de 2018): 1781. http://dx.doi.org/10.3390/molecules23071781.

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It is always a difficult task to assign the peaks recorded from a vibrational spectrum. Herein, we explored a new pathway of density functional theory (DFT) simulation to present three kinds of spectra of ice XIV that can be referenced as inelastic neutron scattering (INS), infrared (IR), and Raman experimental spectrum. The INS spectrum is proportional to the phonon density of states (PDOS) while the photon scattering signals reflect the normal vibration frequencies near the Brillouin zone (BZ) center. Based on good agreements with the experimental data, we identified the relative frequency and made scientific assignments through normal vibration modes analysis. The two hydrogen bond (H-bond) peaks among the ice phases from INS were discussed and the dynamic process of the H-bond vibrations was found to be classified into two basic modes. We deduced that two H-bond modes are a general rule among the ice family and more studies are ongoing to investigate this subject.

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34

Rafailov, P. M., R. Todorov, V. Marinova, D. Z. Dimitrov y M. M. Gospodinov. "Optical spectroscopic study of Ru and Rh doped Bi12TiO20 crystals". Bulgarian Chemical Communications 51, n.º 2 (2019): 219–23. http://dx.doi.org/10.34049/bcc.51.2.4856.

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Bi12TiO20 (BTO) single crystals in pristine state and doped with ruthenium and rhodium are grown by the top-seeded solution growth method and characterized by optical and Raman spectroscopy. The effect of doping on the vibrational and optical properties is studied. The doped crystals show higher absorption in the visible spectral range and higher transmission in the near infrared region as compared to pristine BTO. The performed spatially resolved polarized Raman measurements reveal no significant doping-induced shift of vibrational modes while differences in the LO/TO intensity ratio of the tetrahedral asymmetric stretching vibration are encountered. The observations are discussed in terms of lattice ordering and dopant oxidation states.

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35

Kuramochi, Hikaru, Satoshi Takeuchi, Hironari Kamikubo, Mikio Kataoka y Tahei Tahara. "Fifth-order time-domain Raman spectroscopy of photoactive yellow protein for visualizing vibrational coupling in its excited state". Science Advances 5, n.º 6 (junio de 2019): eaau4490. http://dx.doi.org/10.1126/sciadv.aau4490.

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We report fifth-order time-domain Raman spectroscopy of photoactive yellow protein (PYP), with the aim to visualize vibrational coupling in its excited state. After the ultrashort actinic pump pulse prepared the vibrational coherence and population in the excited state, the evolving vibrational structure was tracked by time-resolved impulsive stimulated Raman spectroscopy using sub–7-fs pulses. The obtained fifth-order time-domain Raman data were translated to a two-dimensional (2D) frequency-frequency correlation map, which visualizes the correlation between low- and high-frequency vibrational modes of the excited state. The 2D map of PYP reveals a cross peak, indicating the coupling between the phenolic C─O stretch mode of the chromophore and the low-frequency modes (~160 cm−1), assignable to the intermolecular motions involving the surrounding hydrogen-bonded amino acids. The unveiled coupling suggests the importance of the low-frequency vibrational motion in the primary photoreaction of PYP, highlighting the unique capability of this spectroscopic approach for studying ultrafast reaction dynamics.

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36

Zhao, Yang, Sheng Zhang, Boyang Zhou, Rongwei Fan, Deying Chen, Zhonghua Zhang y Yuanqin Xia. "Molecular vibrational dynamics in PMMA studied by femtosecond CARS". Modern Physics Letters B 28, n.º 28 (10 de noviembre de 2014): 1450222. http://dx.doi.org/10.1142/s0217984914502224.

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The ultrafast molecular vibrational dynamics in PMMA sheets is studied by femtosecond time-resolved coherent anti-Stokes Raman spectroscopy at room temperature. The C – H stretch modes at 2870 cm-1 and 3008 cm-1 in PMMA sheets are excited and detected. The coherence relaxation times and beat wavenumbers of the Raman modes are obtained.

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37

Flynn, Jessica D. y Jennifer C. Lee. "Raman fingerprints of amyloid structures". Chemical Communications 54, n.º 51 (2018): 6983–86. http://dx.doi.org/10.1039/c8cc03217c.

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38

Fleck, Nicole, Theodore D. C. Hobson, Christopher N. Savory, John Buckeridge, Tim D. Veal, Maria R. Correia, David O. Scanlon, Ken Durose y Frank Jäckel. "Identifying Raman modes of Sb2Se3 and their symmetries using angle-resolved polarised Raman spectra". Journal of Materials Chemistry A 8, n.º 17 (2020): 8337–44. http://dx.doi.org/10.1039/d0ta01783c.

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39

Merlen, A., M. Chaigneau y S. Coussan. "Vibrational modes of aminothiophenol: a TERS and DFT study". Physical Chemistry Chemical Physics 17, n.º 29 (2015): 19134–38. http://dx.doi.org/10.1039/c5cp01579k.

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40

Lamichhane, Hari P. y Gary Hastings. "Calculated Vibrational Properties of Ubisemiquinones". Computational Biology Journal 2013 (10 de enero de 2013): 1–11. http://dx.doi.org/10.1155/2013/807592.

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Density functional theory has been used to calculate harmonic normal mode vibrational frequencies for unlabeled and isotope-labeled ubisemiquinones in both the gas phase and in several solvents. It is shown that four methoxy group conformations are likely to be present in solution at room temperature. Boltzmann weighted infrared and Raman spectra for the four conformers were calculated, and composite spectra that are the sum of the Boltzmann weighted spectra were produced. These composite spectra were compared to experimental FTIR and resonance Raman spectra, and it is shown that the calculated band frequencies, relative band intensities, and C13 and O18 isotope-induced band shifts are in excellent agreement with experiment. The calculations show that the C=O and C=C modes of ubisemiquinone strongly mix with methoxy methyl CH bending vibrations, and that the degree of mixing is altered upon isotope labeling, resulting in complicated changes in mode frequencies, intensities, and composition upon isotope labeling. Upon consideration of the calculated potential energy distributions of the normal modes of ubisemiquinone, and how they change upon isotope labeling, an explanation of some puzzling features in previously published Raman spectra is provided.

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41

Deng, Zexiang, Zhibing Li, Weiliang Wang y Juncong She. "Vibrational properties and Raman spectra of pristine and fluorinated blue phosphorene". Physical Chemistry Chemical Physics 21, n.º 3 (2019): 1059–66. http://dx.doi.org/10.1039/c8cp05699d.

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Using density functional theory, we investigated the vibrational properties and Raman spectra of pristine blue phosphorene and fluorinated blue phosphorene. We have calculated the Raman tensor and thus the angle-dependent Raman intensity for the Raman active modes A_1g and E_g with laser line (633 nm and 532 nm).

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42

Huang, Yining, Zhimei Jiang y Wilhelm Schwieger. "A structural investigation of the singly layered silicates, silinaite and makatite, by vibrational spectroscopy". Canadian Journal of Chemistry 77, n.º 4 (1 de abril de 1999): 495–501. http://dx.doi.org/10.1139/v99-075.

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The IR and Raman spectra of two singly layered silicates, silinaite and makatite, have been investigated. The vibrational spectra were assigned based on previous studies of various silicates. The correlation between vibrational modes and the structural properties of silicates under investigation has been made. The IR and Raman spectra of silinaite are in good agreement with the known structure. However, the observed vibrational data of makatite are not completely consistent with those predicted by a factor group analysis based on the published single-crystal data.Key words: layered silicates, silinaite, makatite, vibrational spectroscopy.

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43

Kaschner, A., H. Siegle, A. Hoffmann, C. Thomsen, U. Birkle, S. Einfeldt y D. Hommel. "Influence of Doping on the Lattice Dynamics of Gallium Nitride". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 327–32. http://dx.doi.org/10.1557/s1092578300002672.

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We present results of Raman-scattering experiments on GaN doped with Si, C, and Mg, respectively, grown by molecular beam epitaxy (MBE). The influence of the different dopants on strain and free-carrier concentration was investigated. Furthermore, we report on several local vibrational modes (LVM) around 2200 cm−1 in Raman spectra of highly Mg-doped GaN. A possible explanation of these high-energy modes in terms of hydrogen-related vibrations is given. We also found a variety of new structures in the range of the GaN host lattice phonons. Secondary ion mass spectroscopy (SIMS) was applied to determine the concentration of magnesium and unintentionally incorporated hydrogen.

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44

Rafailov, Peter, Dimitre Dimitrov, Yen-Fu Chen, Chi-Shen Lee y Jenh-Yih Juang. "Symmetry of the Optical Phonons in LuVO4: A Raman Study". Crystals 10, n.º 5 (26 de abril de 2020): 341. http://dx.doi.org/10.3390/cryst10050341.

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A thorough analysis of the first-order vibrational spectrum of LuVO4 is presented by using polarized micro-Raman spectroscopy with special focus on the phonon modes with the weakest intensity and occasional controversial assignment. Group-theory analysis is carried out to demonstrate the determination of numbers and symmetries of the Raman active modes. Crystal- and correlation-field splitting effects in the vibrational spectrum of LuVO4 are discussed. Under conditions adjusted to minimize the birefringence effects we recorded, in each main scattering configuration, a series of Raman spectra in different sample orientations achieved by rotating the sample around the incident laser beam. The dependence of the Raman intensity on the rotational angle allowed us to identify the correct symmetry of the phonons with exceptionally weak scattering cross-section. A complete assignment of all twelve first-order Raman active phonons of LuVO4 is thus obtained.

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45

Ristić, D., M. Ivanda, K. Furić, U. V. Desnica, M. Buljan, M. Montagna, M. Ferrari, A. Chiasera y Y. Jestin. "Raman scattering on quadrupolar vibrational modes of spherical nanoparticles". Journal of Applied Physics 104, n.º 7 (2008): 073519. http://dx.doi.org/10.1063/1.2981083.

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46

Boukenter, A., B. Champagnon, E. Duval, J. L. Rousset, J. Dumas y J. Serughetti. "Vibrational modes in silica aerogels: low-frequency Raman scattering". Journal of Physics C: Solid State Physics 21, n.º 34 (10 de diciembre de 1988): L1097—L1102. http://dx.doi.org/10.1088/0022-3719/21/34/001.

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47

Uematsu, Masashi. "Raman scattering of Si localized vibrational modes in InAs". Journal of Applied Physics 69, n.º 3 (febrero de 1991): 1781–83. http://dx.doi.org/10.1063/1.348917.

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48

Rafailov, P. M., V. G. Hadjiev, H. Jantoljak y C. Thomsen. "Raman depolarization ratio of vibrational modes in solid C60". Solid State Communications 112, n.º 9 (octubre de 1999): 517–20. http://dx.doi.org/10.1016/s0038-1098(99)00422-6.

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49

Ge, Yun-Cheng, Li-Xia Li y Chao-Zhong Zhao. "Temperature-Dependent Raman Study on Vibrational Modes in LiTaO3". Spectroscopy Letters 30, n.º 3 (abril de 1997): 567–74. http://dx.doi.org/10.1080/00387019708006683.

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50

Blanton, Eric W., Mark Hagemann, Keliang He, Jie Shan, Walter R. L. Lambrecht y Kathleen Kash. "Raman study of the vibrational modes in ZnGeN2 (0001)". Journal of Applied Physics 121, n.º 5 (7 de febrero de 2017): 055704. http://dx.doi.org/10.1063/1.4975040.

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