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Journal articles on the topic 'Raman thermal'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Kuball, M., F. Demangeot, J. Frandon, M. A. Renucci, N. Grandjean, and O. Briot. "Thermal Stability of GaN Investigated by Raman Scattering." MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 653–58. http://dx.doi.org/10.1557/s1092578300003203.

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We have investigated the thermal stability of GaN using Raman scattering. Noninvasive optical monitoring of the degradation of GaN during high-temperature processing has been demonstrated. GaN samples grown by molecular-beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOCVD) were studied. Characteristic features in the Raman spectrum identify three thermal stability regimes: (1) annealing below 900°C does not affect the GaN Raman spectrum; (2) annealing between 900°C and 1000°C results in the appearance of disorder-induced Raman scattering between the E2 and A1(LO) phonon; (3) annealing at temperatures higher than 1000°C gives rise to distinct Raman modes at 630 cm−1, 656 cm−1 and 770 cm−1. The evolution of the Raman spectrum of GaN with increasing annealing temperature is discussed in terms of disorder-induced Raman scattering. We find clear indications for an interfacial reaction between GaN and sapphire for annealing temperatures higher than 1000°C.

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2

Anaya, Julián, Carmelo Prieto, Alfredo Torres, Alonso Martín-Martín, Jorge Souto, Juan Jiménez, Andres Rodríguez, and Tomás Rodríguez. "MicroRaman Spectroscopy of Si Nanowires: Influence of Size." Materials Science Forum 725 (July 2012): 255–58. http://dx.doi.org/10.4028/www.scientific.net/msf.725.255.

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Si Nanowires (NWs) were studied by Raman microspectroscopy. The Raman spectrum of the NWs reveals important thermal effects, which broaden and shift the one phonon Raman bands. The low thermal conductivity of the NWs and the low thermal dissipation are responsible for the temperature enhancement in the NW under the excitation with the laser beam. We have modeled, using finite element methods, the interaction between the laser beam and the NWs. The Raman spectrum of Si NWs is interpreted in terms of the temperature induced by the laser beam excitation, in correlation with finite element methods (fem) for studying the interaction between the laser beam and the NWs.

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3

Biswas, A. "Thermal Processing of o-Terphenyl: A Raman Study." Applied Spectroscopy 47, no. 4 (April 1993): 458–62. http://dx.doi.org/10.1366/0003702934334921.

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Raman spectra from o-terphenyl sealed in glass capillary tubes were acquired over temperatures ranging from 233 K to 343 K. Over this temperature range, o-terphenyl can exist in the solid-crystalline, molten, supercooled-liquid, and amorphous-glassy states. Representative structure-sensitive spectra are presented along with a qualitative description. The lattice spectral feature occurring at a Raman shift of 123 cm−1 displays abrupt changes in profile and intensity as melting and glass transition occur. The intensity ratio of the C-C stretching 996-cm−1 line and C-H stretching line at 1008 cm−1 displays a change related to the transformation of the ordered-crystalline phase to the disordered-liquid or glassy state. At a Raman shift of 1162 cm−1 the solid-crystalline state shows a splitting due to the effect of the crystal field. The possibility of using these structure-sensitive Raman characteristics for in situ diagnostics during materials processing is discussed.

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4

BARR, H. C., T. J. M. BOYD, and A. V. LUKYANOV. "Raman gain against a background of non-thermal ion fluctuations in a plasma." Journal of Plasma Physics 64, no. 5 (November 2000): 623–30. http://dx.doi.org/10.1017/s0022377800008837.

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A complex stimulated Raman scattering event against a background of non-thermal ion acoustic waves in an inhomogeneous plasma is described. We obtain analytic forms for the Raman gain due to a five-wave interaction consisting of conventional three-wave Raman scattering followed by the decay of the Raman Langmuir wave into a second Langmuir wave (or a second scattered light wave) and an ion acoustic wave. Very modest levels of ion waves produce a significant effect on Raman convective gain. A combination of plasma inhomogeneity and suprathermal ion fluctuations may offer a means for the control of Raman gain.

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5

Kato, Ryoei, and Kun'ichi Miyazawa. "Raman Laser Polymerization ofC60Nanowhiskers." Journal of Nanotechnology 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/101243.

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Photopolymerization ofC60nanowhiskers (C60NWs) was investigated by using a Raman spectrometer in air at room temperature, since the polymerizedC60NWs are expected to exhibit a high mechanical strength and a thermal stability. ShortC60NWs with a mean length of 4.4 μm were synthesized by LLIP method (liquid-liquid interfacial precipitation method). TheAg(2) peak ofC60NWs shifted to the lower wavenumbers with increasing the laser beam energy dose, and an energy dose more than about 1520 J/mm2was found necessary to obtain the photopolymerizedC60NWs. However, excessive energy doses at high-power densities increased the sample temperature and lead to the thermal decomposition of polymerizedC60molecules.

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6

Som, Sanjoy M., and Bernard H. Foing. "Thermal degradation of organic material by portable laser Raman spectrometry." International Journal of Astrobiology 11, no. 3 (February 28, 2012): 177–86. http://dx.doi.org/10.1017/s1473550412000079.

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AbstractRaman spectrometry has been established as an instrument of choice for studying the structure and bond type of known molecules, and identifying the composition of unknown substances, whether geological or biological. This versatility has led to its strong consideration for planetary exploration. In the context of the ExoGeoLab and ExoHab pilot projects of ESA-ESTEC & ILEWG (International Lunar Exploration Working Group), we investigated samples of astrobiological interest using a portable Raman spectrometer lasing at 785 nm and discuss implications for planetary exploration. We find that biological samples are typically best observed at wavenumbers >1100 cm−1, but their Raman signals are often affected by fluorescence effects, which lowers their signal-to-noise ratio. Raman signals of minerals are typically found at wavenumbers <1100 cm−1, and tend to be less affected by fluorescence. While higher power and/or longer signal integration time improve Raman signals, such power settings are detrimental to biological samples due to sample thermal degradation. Care must be taken in selecting the laser wavelength, power level and integration time for unknown samples, particularly if Raman signatures of biological components are anticipated. We include in the Appendices tables of Raman signatures for astrobiologically relevant organic compounds and minerals.

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7

Mansour, S. F., El Sayed Yousef, M. Y. Hassaan, and A. M. Emara. "Thermal, IR, Raman characteristics, Raman gain coefficient and bandwidths in quaternary glasses." Solid State Sciences 37 (November 2014): 33–39. http://dx.doi.org/10.1016/j.solidstatesciences.2014.08.004.

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8

LEE, HYEON-KEUN, and DO KYUNG KIM. "DEFECT CHARACTERIZATION OF HIGH THERMAL CONDUCTIVITY CaF2 DOPED AlN CERAMICS BY RAMAN SPECTROSCOPY." Modern Physics Letters B 23, no. 31n32 (December 30, 2009): 3869–76. http://dx.doi.org/10.1142/s0217984909021934.

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Calcium fluoride additive was used to produce high thermal conductivity AlN ceramics which has no grain boundary phase. Thermal conductivity of AlN is determined by the point defect, represented as oxygen related defect, within the AlN grain. The defect density characterization of high thermal conductivity CaF 2 doped AlN ceramics after heat treatment was conducted by Raman spectroscopy. As measure Raman linewidth broadening, the point defect density variation after heat treatment and corresponding thermal conductivity change was investigated.

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9

Serrano, J. R., L. M. Phinney, and S. P. Kearney. "Micro-Raman thermometry of thermal flexure actuators." Journal of Micromechanics and Microengineering 16, no. 7 (April 28, 2006): 1128–34. http://dx.doi.org/10.1088/0960-1317/16/7/004.

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10

Bai, Zhenxu, Zhanpeng Zhang, Kun Wang, Jia Gao, Zhendong Zhang, Xuezong Yang, Yulei Wang, Zhiwei Lu, and Richard P. Mildren. "Comprehensive Thermal Analysis of Diamond in a High-Power Raman Cavity Based on FVM-FEM Coupled Method." Nanomaterials 11, no. 6 (June 15, 2021): 1572. http://dx.doi.org/10.3390/nano11061572.

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Despite their extremely high thermal conductivity and low thermal expansion coefficients, thermal effects in diamond are still observed in high-power diamond Raman lasers, which proposes a challenge to their power scaling. Here, the dynamics of temperature gradient and stress distribution in the diamond are numerically simulated under different pump conditions. With a pump radius of 100 μm and an absorption power of up to 200 W (corresponding to the output power in kilowatt level), the establishment period of thermal steady-state in a millimeter diamond is only 50 μs, with the overall thermal-induced deformation of the diamond being less than 2.5 μm. The relationship between the deformation of diamond and the stability of the Raman cavity is also studied. These results provide a method to better optimize the diamond Raman laser performance at output powers up to kilowatt-level.

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11

Wang, Tianyu, Shen Xu, David H. Hurley, Yanan Yue, and Xinwei Wang. "Frequency-resolved Raman for transient thermal probing and thermal diffusivity measurement." Optics Letters 41, no. 1 (December 18, 2015): 80. http://dx.doi.org/10.1364/ol.41.000080.

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12

Frost, Ray L., and Matt L. Weier. "Thermal treatment of whewellite—a thermal analysis and Raman spectroscopic study." Thermochimica Acta 409, no. 1 (January 2004): 79–85. http://dx.doi.org/10.1016/s0040-6031(03)00332-0.

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13

Geisler, Thorsten, Robert T. Pidgeon, Wilhelm van Bronswijk, and Ron Pleysier. "Kinetics of thermal recovery and recrystallization of partially metamict zircon: a Raman spectroscopic study." European Journal of Mineralogy 13, no. 6 (November 26, 2001): 1163–76. http://dx.doi.org/10.1127/0935-1221/2001/0013-1163.

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14

Suss, Nicole, Anna Ritscher, Martin Lerch, and Ilias Efthimiopoulos. "Anharmonic Effects in Ordered Kesterite-Type Cu2ZnSnS4." Solids 2, no. 4 (November 24, 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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15

Jin, Rui Min, Ding Zhen Li, Lan Li Chen, Xin Feng Guo, and Jing Xiao Lu. "Crystallization of Hydrogenated Amorphous Silicon by Rapid Thermal Method." Key Engineering Materials 428-429 (January 2010): 444–46. http://dx.doi.org/10.4028/www.scientific.net/kem.428-429.444.

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Amorphous silicon films prepared by PECVD on silex glass substrate has been crystallized by rapid thermal annealing (RTA), From the Raman spectra and scanning electronic microscope (SEM), it was found that the Raman spectra wa best crystallized at 950°C for 5 min. The thin film made by RTA was smoothly and perfect structure.

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16

Khatibi, Seyedalireza, Mehdi Ostadhassan, David Tuschel, Thomas Gentzis, and Humberto Carvajal-Ortiz. "Evaluating Molecular Evolution of Kerogen by Raman Spectroscopy: Correlation with Optical Microscopy and Rock-Eval Pyrolysis." Energies 11, no. 6 (May 31, 2018): 1406. http://dx.doi.org/10.3390/en11061406.

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Vitrinite maturity and programmed pyrolysis are conventional methods to evaluate organic matter (OM) regarding its thermal maturity. Moreover, vitrinite reflectance analysis can be difficult if prepared samples have no primary vitrinite or dispersed widely. Raman spectroscopy is a nondestructive method that has been used in the last decade for maturity evaluation of organic matter by detecting structural transformations, however, it might suffer from fluorescence background in low mature samples. In this study, four samples of different maturities from both shale formations of Bakken (the upper and lower members) Formation were collected and analyzed with Rock-Eval (RE) and Raman spectroscopy. In the next step, portions of the same samples were then used for the isolation of kerogen and analyzed by Raman spectroscopy. Results showed that Raman spectroscopy, by detecting structural information of OM, could reflect thermal maturity parameters that were derived from programmed pyrolysis. Moreover, isolating kerogen will reduce the background noise (fluorescence) in the samples dramatically and yield a better spectrum. The study showed that thermal properties of OM could be precisely reflected in Raman signals.

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17

CHIEN, T. Y., C. T. CHIA, T. C. LIN, and S. C. LEE. "DETERMINE THE SIZE AND OXIDIZATION OF SILICON QUANTUM DOTS PREPARED BY THERMAL EVAPORATION METHOD." International Journal of Nanoscience 02, no. 04n05 (August 2003): 357–62. http://dx.doi.org/10.1142/s0219581x03001395.

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Raman spectrum has been used to analyze the size of Silicon (Si) quantum dots (QDs) prepared by thermal evaporation. Si QDs were grown in thermal evaporation chamber with Ar gas presented. We determined the average size of the Si QDs by analyzing the optical phonon of Si QDs in Raman spectra. We found that the higher the Ar gas pressure in the chamber, the larger the average size of Si QDs grown by thermal evaporation. We found the Si dot size reaches a maximum, about 7.5 nm in diameter, when Ar gas pressure is about 2–3 torr. The oxidization of Si QDs is also observed by Raman spectra. The life time of oxidized process was about 46 days.

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18

Xia, H. R., G. W. Lu, P. Zhao, S. Q. Sun, X. L. Meng, X. F. Cheng, L. J. Qin, L. Zhu, and Z. H. Yang. "Lattice thermal vibration and its nonharmonic effect in Nd-doped rare-earth vanadates." Journal of Materials Research 20, no. 1 (January 2005): 30–35. http://dx.doi.org/10.1557/jmr.2005.0013.

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The 0.5 at.% Nd-doped gadolinium and yttrium orthovanadate, Nd:GdVO4 (NGV) and Nd:YVO4 (NYV), crystallize in the tetragonal space group I41/amd and are of a zircon-type structure with the lattice constants a = b = 0.7212(6) and c = 0.6348(3) nm for NGV and a = b = 0.7123(5) and c = 0.6292(5) nm for NYV. At high and room temperatures, the Raman spectra of NYV are much the same; however, the Raman spectra of NGV are different from those of NYV. The scattering intensity of NGV is largely stronger than that of NYV. Nonharmonic effect of the lattice thermal vibrations, including the thermal conductivity and expansion, is theoretically and experimentally discussed. The theoretical results roughly indicate that a crystal with the larger integrated intensities of the Raman-scattering peaks under the cutoff value of linear dependence of Debye frequency versus the temperature has the larger thermal conductivity. The experimental data of the thermal conductivity of the five samples show that the thermal conductivity of NGV is more outstanding than that of NYV in every direction. Compared the integrated intensity ratio IG/IY between the NGV and NYV Raman-scattering peaks under the cutoff wavenumber of Debye frequency with the ratio κG/κY of their crystal thermal conductivity, it may be seen that the Raman results are basically in agreement with the conductivity measurements within our experimental error. The experimental datum of the thermal conductivity of NYAG (Nd-doped yttrium aluminum garnet) with the cubic symmetry and stable laser properties and thermodynamics parameters, which is often considered as a comparable standard, approximately approaches to the average value of the NGV thermal conductivity in the a and c directions. The thermal-expansion data of NGV exhibit its small line-expansion coefficients, which imply that the large thermal conductivity is needed and existential and that NGV is more capable to bear a large temperature gradient, therefore, is also more suitable as a solid-state laser material than NYV crystals.

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19

Rani, Chanchal, Devesh K. Pathak, Manushree Tanwar, Suchita Kandpal, Tanushree Ghosh, Maxim Yu Maximov, and Rajesh Kumar. "Anharmonicity induced faster decay of hot phonons in rutile TiO₂ nanorods: a Raman spectromicroscopy study." Materials Advances 3, no. 3 (2022): 1602–8. http://dx.doi.org/10.1039/d1ma00940k.

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20

Schito, Andrea, and Sveva Corrado. "An automatic approach for characterization of the thermal maturity of dispersed organic matter Raman spectra at low diagenetic stages." Geological Society, London, Special Publications 484, no. 1 (September 17, 2018): 107–19. http://dx.doi.org/10.1144/sp484.5.

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AbstractAn automatic approach for analyses of Raman spectra of dispersed organic matter in diagenesis is proposed in this work. The need for a reproducible method of thermal maturity assessment by means of Raman spectroscopic analyses on the organic matter is essential for the development of this technique as a robust support in organic petrographical analyses. The new method was tested on concentrated kerogen derived from a set of 33 samples that originated from cuttings from a 5000 m-thick section drilled in offshore Angola. The proposed method can be applied separately in the D and G bands regions of the Raman spectra, and uses a fitting approach based on asymmetrical Gaussian deconvolution and on the measurement of the integrated area. Results from this work demonstrate that Raman parameters carried out by the new methods reflect the increase in aromaticity in kerogen in diagenesis. Finally, two parametric equations have been proposed to correlate Raman parameters and thermal maturity: the first is for the thermal maturity interval between 0.3 and 1.5% Ro; and the second has a higher precision of between 1.0 and 1.5% Ro. The two equations are the result of a multi-linear regression based on robust correlations between Raman parameters and vitrinite reflectance (Ro%).

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21

MATHEW, VARGHESE, JOCHAN JOSEPH, SABU JACOB, LIZYMOL XAVIER, and K. E. ABRAHAM. "SPECTROSCOPIC AND THERMAL STUDIES OF GEL-GROWN COPPER MALONATE CRYSTALS." Modern Physics Letters B 24, no. 11 (May 10, 2010): 1135–43. http://dx.doi.org/10.1142/s0217984910023177.

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Copper malonate crystals were grown using silica gel as the growth medium. The grown crystals were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT Raman). The thermal decomposition of the compound was investigated using thermogravimetry (TG) and derivative thermogravimetry (DTG) measurements.

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22

Cao, Y. G., X. L. Chen, Y. C. Lan, Y. P. Xu, T. Xu, and J. K. Liang. "Synthesis, Raman scattering, and infrared spectra of a new condensed form of GaN nanophase material." Journal of Materials Research 15, no. 2 (February 2000): 267–69. http://dx.doi.org/10.1557/jmr.2000.0042.

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A new form of transparent condensed nanophase material of GaN was synthesized directly by ammono-thermal synthetic route. Nano-sized effects and thermal stability of that material were investigated through Raman scattering and infrared spectra. Compared with bulk GaN, we observed the Raman low-energy-shift of the phonon frequency of E2(high) and the transverse optical mode [E1(TO)], the infrared high-energy-shift of, ωT, and the variation of relative intensity IE2/E1(TO). These characteristics can be attributed to the existence of the interface effects and the vacancy of N in the GaN nanophase material. This material has a high thermal stability even at 900 °C as indicated through infrared and Raman spectral investigation of annealed samples of as-synthesized nanophase material.

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23

Wenelska, Karolina, and Ewa Mijowska. "Preparation, thermal conductivity, and thermal stability of flame retardant polyethylene with exfoliated MoS2/MxOy." New Journal of Chemistry 41, no. 22 (2017): 13287–92. http://dx.doi.org/10.1039/c7nj02566a.

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In this work, exfoliated molybdenum disulfide (MoS₂) modified by a metal oxide (MoS₂/M_xO_y) was prepared by a hydrothermal method and characterized by atomic force microscopy (AFM), Raman spectroscopy and transmission electron microscopy (TEM).

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24

KIMACHI, Hirohisa, Wataru OTA, Kazunari FUJIYAMA, Shinji YAMAMOTO, Kenta NIWA, and Daisuke KANEKO. "Evaluation of Thermal Damage of Thermal Barrier Coatings by Using Raman Microspectroscopy." Journal of the Society of Materials Science, Japan 59, no. 6 (2010): 455–61. http://dx.doi.org/10.2472/jsms.59.455.

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25

Wattananurak, Pilantana, Natthapong Monarumit, Rattanawalee Chooyoung, Krit Won-In, Sutharat Chotikaprakhan, and Somruedee Satitkune. "FWHM Calculation of Zircon Gem-Materials before and after Thermal Enhancement." Key Engineering Materials 737 (June 2017): 599–603. http://dx.doi.org/10.4028/www.scientific.net/kem.737.599.

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Zircon samples from Ubon Ratchathani, Thailand; Rattanakiri, Cambodia and Dak Nong, Vietnam change their color from light brown and reddish-brown to blue color after thermal enhancement at 1000 ๐C in reducing condition for 60 min. The high temperature is one of the factors for the zircon structure to recrystallize. The objective of this study is to describe the crystal structure of zircon samples before and after thermal enhancement. Zircon is a metamict mineral whose structure is destroyed by some trace elements. There are radioactive elements such as U and Th in the zircon structure. In this study, Raman spectroscopy was used to analyze the molecular vibration in zircon structure before and after thermal enhancement. As a result, the Raman spectra of zircon samples after thermal enhancement show the Raman shift at peak position of V3(SiO4) stretching around 1008cm-1to higher wavenumber concerning to the full width at half maximum (FWHM) values calculated by PyMCA software. The results could be summarized that the metamict zircon will be recrystallized to the crystalline zircon after thermal enhancement. The advantage of this study is about the identification of zircon before and after thermal enhancement.

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26

Xu, Yanru, Xiaoguang Zhao, Aobo Li, Yanan Yue, Jin Jiang, and Xin Zhang. "Plasmonic heating induced by Au nanoparticles for quasi-ballistic thermal transport in multi-walled carbon nanotubes." Nanoscale 11, no. 16 (2019): 7572–81. http://dx.doi.org/10.1039/c9nr00901a.

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27

Lee, Chi-Chun, Chien-Yen Huang, Hao-Yun Huang, Chao-Ming Chen, and Chia-Han Tsou. "Comparison between Self-Raman Nd:YVO4 Lasers and NdYVO4/KGW Raman Lasers at Lime and Orange Wavelengths." Applied Sciences 11, no. 22 (November 22, 2021): 11068. http://dx.doi.org/10.3390/app112211068.

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The comparison of output powers between self-Raman Nd:YVO4 lasers and Nd:YVO4/KGW Raman lasers operating at lime and orange wavelengths is presented. We exploit the LBO crystal with cutting angle θ = 90° and φ = 8° for the lime wavelengths, and then we change the angle to θ = 90° and φ = 3.9° for the orange wavelengths. In self-Raman Nd:YVO4 lasers, experimental results reveal that thermal loading can impact on the output performances, especially at the high pump power. However, by using a KGW crystal as Raman medium can remarkably share the thermal loading from gain medium. Besides, the designed coating for high reflectively at the Stokes field on the surface of KGW also improved the beam quality and reduced the lasing threshold. For self-Raman Nd:YVO4 lasers, we have achieved the output powers of 6.54 W and 5.12 W at 559 nm and 588 nm, respectively. For Nd:YVO4/KGW Raman lasers, the output powers at 559 nm and 589 nm have been increased to 9.1 W and 7.54 W, respectively. All lasers operate at a quasi-CW regime with the repetition rate 50 Hz and the duty cycle 50%.

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28

Wei, Yuehua, Zhenhua Wei, Xiaoming Zheng, Jinxin Liu, Yangbo Chen, Yue Su, Wei Luo, et al. "Stress Effects on Temperature-Dependent In-Plane Raman Modes of Supported Monolayer Graphene Induced by Thermal Annealing." Nanomaterials 11, no. 10 (October 17, 2021): 2751. http://dx.doi.org/10.3390/nano11102751.

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The coupling strength between two-dimensional (2D) materials and substrate plays a vital role on thermal transport properties of 2D materials. Here we systematically investigate the influence of vacuum thermal annealing on the temperature-dependence of in-plane Raman phonon modes in monolayer graphene supported on silicon dioxide substrate via Raman spectroscopy. Intriguingly, raising the thermal annealing temperature can significantly enlarge the temperature coefficient of supported monolayer graphene. The derived temperature coefficient of G band remains mostly unchanged with thermal annealing temperature below 473 K, while it increases from −0.030 cm−1/K to −0.0602 cm−1/K with thermal annealing temperature ranging from 473 K to 773 K, suggesting the great impact of thermal annealing on thermal transport in supported monolayer graphene. Such an impact might reveal the vital role of coupling strength on phonon scattering and on the thermal transport property of supported monolayer graphene. To further interpret the thermal annealing mechanism, the compressive stress in supported monolayer graphene, which is closely related to coupling strength and is studied through the temperature-dependent Raman spectra. It is found that the variation tendency for compressive stress induced by thermal annealing is the same as that for temperature coefficient, implying the intense connection between compressive stress and thermal transport. Actually, 773 K thermal annealing can result in 2.02 GPa compressive stress on supported monolayer graphene due to the lattice mismatch of graphene and substrate. This study proposes thermal annealing as a feasible path to modulate the thermal transport in supported graphene and to design future graphene-based devices.

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29

Osipov, Armenak A. "High-temperature Raman spectroscopy." Pure and Applied Chemistry 91, no. 11 (November 26, 2019): 1749–56. http://dx.doi.org/10.1515/pac-2019-0115.

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Abstract Raman spectroscopy has a long-standing reputation as a powerful tool for structural investigation of the various materials. However, application of this technique to study the melt structure directly under high-temperature requires its certain modification. The methods of the registration of high-temperature Raman spectra were considered. Particular attention was paid to considering the systems on time-resolved filtering of the thermal radiation.

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30

Ogorodova, L. P., Yu D. Gritsenko, M. F. Vigasina, and L. V. Melchakova. "Natural Kaersutite: FTIR, Raman, Thermal, and Thermochemical Studies." Geochemistry International 57, no. 6 (June 2019): 716–21. http://dx.doi.org/10.1134/s0016702919060089.

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31

Kuball, M., F. Demangeot, J. Frandon, M. A. Renucci, J. Massies, N. Grandjean, R. L. Aulombard, and O. Briot. "Thermal stability of GaN investigated by Raman scattering." Applied Physics Letters 73, no. 7 (August 17, 1998): 960–62. http://dx.doi.org/10.1063/1.122052.

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32

Doerk, Gregory S., Carlo Carraro, and Roya Maboudian. "Single Nanowire Thermal Conductivity Measurements by Raman Thermography." ACS Nano 4, no. 8 (July 22, 2010): 4908–14. http://dx.doi.org/10.1021/nn1012429.

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33

Ogorodova, L. P., Yu D. Gritsenko, M. F. Vigasina, and L. V. Melchakova. "Natural kaersutite: ftir, raman, thermal and thermochemical investigations." Геохимия 64, no. 6 (June 26, 2019): 651–57. http://dx.doi.org/10.31857/s0016-7525646651-657.

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A thermochemical study of the natural oxo-amphibole ─ kaersutite Na0.4K0.3(Ca1.6Na0.4)(Mg2.9Fe0.82+Al0.7Ti0.6Fe0.53+)[Si6.1Al1.9O22](OH)0.2O1.8.(alkaline basalts of Mongolia) was performed on a Tian-Calvet microcalorimeter. The enthalpy of formation from the elements ∆fH el0(298.15 K) = – 12102 ± 16 kJ/mol) was obtained by the method of high-temperature melt solution calorimetry. The entropy, enthalpy and Gibbs energy of the formation of the end-members of the isomorphic series kaersutite NaCa2Mg3TiAl[Si6Al2O22]O2 – ferri-kaersutite NaCa2Mg3TiFe3+[Si6Al2O22]O2 were estimated.

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34

Abel, Mark R., Tanya L. Wright, William P. King, and Samuel Graham. "Thermal Metrology of Silicon Microstructures Using Raman Spectroscopy." IEEE Transactions on Components and Packaging Technologies 30, no. 2 (June 2007): 200–208. http://dx.doi.org/10.1109/tcapt.2007.897993.

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35

Heremans, J., I. Rahim, and M. S. Dresselhaus. "Thermal conductivity and Raman spectra of carbon fibers." Physical Review B 32, no. 10 (November 15, 1985): 6742–47. http://dx.doi.org/10.1103/physrevb.32.6742.

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36

Karpierz, Monika, Jan Suchanicz, Krzysztof Konieczny, Dorota Sitko, Pascal Marchet, and Urszula Lewczuk. "Thermal, Raman and dielectric study of 0.5K0.5Bi0.5TiO3–0.5PbTiO3ceramics." Phase Transitions 88, no. 7 (May 12, 2015): 662–67. http://dx.doi.org/10.1080/01411594.2015.1020311.

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37

Brezeștean, Ioana Andreea, Daniel Marconi, Alia Colniță, Alexandra Ciorîță, Septimiu Cassian Tripon, Zina Vuluga, Mihai Cosmin Corobea, Nicoleta Elena Dina, and Ioan Turcu. "Scanning Electron Microscopy and Raman Spectroscopy Characterization of Structural Changes Induced by Thermal Treatment in Innovative Bio-Based Polyamide Nanocomposites." Chemosensors 11, no. 1 (December 28, 2022): 28. http://dx.doi.org/10.3390/chemosensors11010028.

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A comprehensive Raman scattering-based characterization of a full bio-based polyamide loaded with graphene nanoplatelets or layered double hydroxides (LDH) was assessed. The potential of the Raman spectroscopy was used to reveal several particularities of the nanocomposite structures induced by thermal treatment. Thus, a complete morpho-structural picture was obtained in combination with scanning electron microscopy (SEM) analysis of the neat polyamide and polyamide nanocomposites exposed at different thermal conditions (room temperature, 80 °C, and 145 °C). The analysis of G, D and 2D Raman peaks and their relative intensity ratio ID/IG, revealed the fact that the presence of graphene in polyamide is suitable for improving the essential physical properties and is also responsible for the decrease in the defects’ occurrence in the graphene layers. The surface of nanocomposites based on full bio-based polyamide, with different 2D fillers (graphenic and non-graphenic structures), was carefully evaluated before and after the thermal treatment by employing SEM and Raman analyses. The two thermal treatments allowed different chain mobility of the polymer (first temperature being over the polymer Tg and second one close to the melting phase in the viscoelastic stage). The spectroscopic and microscopic investigation was used to determine the conformational changes in filler aggregates and polymer surface, respectively.

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Etz, Edgar S., Wilbur S. Hurst, and Albert Feldman. "Correlation of the Raman spectra with the thermal conductivity of a set of diamond wafers prepared by chemical vapor deposition." Journal of Materials Research 16, no. 6 (June 2001): 1694–711. http://dx.doi.org/10.1557/jmr.2001.0235.

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Raman spectroscopy, at laser excitation wavelengths of 514.5, 785, and 1064 nm, is used to study a set of chemical-vapor-deposited (CVD) diamond wafers of known thermal conductivity κ. The in-plane thermal conductivity (at 25 °C) of the diamond wafers ranges from 4 to 22 W cm−1 K−1 and represents a wide range of diamond quality. The spectra were obtained from both macro/micro- sampling measurements, examining the top and bottom wafer surface, as well as wafer cross-sections. Discussed are the peak positions and linewidths of the Raman bands and their relation to sp3-bonded diamond and sp2-bonded carbon in the context of diamond quality and perfection, and the effects of wafer heterogeneities. The detailed analysis of the Raman spectra provides a robust correlation with the room-temperature bulk (or macroscopic) thermal conductivity of these samples. The correlation is made through the determination of the band area ratios of the diamond Raman line at 1333 cm−1 to that of the 1550 cm−1 band characteristic of nondiamond carbon impurities. This dependence is most pronounced for the Fourier-transform Raman data obtained with infrared excitation at 1064 nm, due to resonance enhancement, and therefore allows the detection of carbon impurities, especially for high-quality CVD diamond.

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39

Sokalski, Peter, Zherui Han, Gabriella Coloyan Fleming, Brandon Smith, Sean E. Sullivan, Rui Huang, Xiulin Ruan, and Li Shi. "Effects of hot phonons and thermal stress in micro-Raman spectra of molybdenum disulfide." Applied Physics Letters 121, no. 18 (October 31, 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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40

Naqvi, Furqanul Hassan, and Jae-Hyeon Ko. "Structural Phase Transitions and Thermal Degradation Process of MAPbCl3 Single Crystals Studied by Raman and Brillouin Scattering." Materials 15, no. 22 (November 17, 2022): 8151. http://dx.doi.org/10.3390/ma15228151.

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Raman spectroscopy was applied to MAPbCl3 single crystals in a wide frequency range from 10 to 3500 cm−1 over a broad temperature range from −196 °C to 200 °C including both two structural phase transitions and a thermal degradation range. Low-frequency lattice modes of MAPbCl3 were revealed for the first time, which showed discontinuous anomalies along with the change in the number of Raman modes at the transition points of −114 °C and −110 °C. Several Raman modes related to the C–N stretching and MA rocking modes in addition to the lattice modes displayed temperature dependences similar to those of MAPbBr3 in both Raman shifts and half widths, indicating that the MA cation arrangement and H–halide bond interactions behave similarly in both systems during the phase transition. The substantial increase in the half widths of nearly all Raman modes especially suggests that the dynamic disorder caused by the free rotational motions of MA cations induces significant anharmonicity in the lattice and thus, reduces the phonon lifetimes. High-temperature Raman and Brillouin scattering measurements showed that the spectral features changed drastically at ~200 °C where the thermal decomposition of MAPbCl3 into PbCl2 began. This result exhibits that combined Raman and Brillouin spectroscopic techniques can be a useful tool in monitoring temperature-induced or temporal changes in lead-based halide perovskite materials.

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41

Bernardini, Simone, Fabio Bellatreccia, Giancarlo Della Ventura, Paolo Ballirano, and Armida Sodo. "Raman spectroscopy and laser-induced degradation of groutellite and ramsdellite, two cathode materials of technological interest." RSC Advances 10, no. 2 (2020): 923–29. http://dx.doi.org/10.1039/c9ra08662e.

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Raman spectra of groutellite and ramsdellite were provided and the thermal stability under the laser beam was investigated. Raman mapping allows the study of their distribution, which play a key-role in electrochemical activity of these compounds.

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42

Bamberger, Carlos E., George M. Begun, and C. Sue MacDougall. "Raman Spectroscopy of Potassium Titanates: Their Synthesis, Hydrolytic Reactions, and Thermal Stability." Applied Spectroscopy 44, no. 1 (January 1990): 30–37. http://dx.doi.org/10.1366/0003702904085732.

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The majority of the potassium titanates described in the literature were synthesized, and their Raman spectra recorded. The identity of the compounds K2TiO3, K2Ti2O5, K2Ti4O9, K2Ti6O13, and K2Ti8O17 was confirmed by x-ray diffraction. Raman spectroscopy was then used to study the hydrolysis, under different conditions, of K2Ti2O5 and of K2Ti4O9. On drying of the hydrolysis products, the following species were found to form: K2(H2O)0.66 Ti8O16(OH)2, K1.33(H2O)0.33Ti4O8.33(OH)0.67, and H2Ti8O17. On ignition at temperatures of 500–600°C these species converted, respectively, to K2Ti8O17, K2Ti6O13, and TiO2(B). Raman spectroscopy was used to establish that (1) K6Ti4O11 consists of a mixture of K2TiO3 and a new compound K4Ti3O8; (2) K2Ti3O7 consists of a mixture of K2Ti2O5 and K2Ti4O9, and (3) K2Ti5O11 consists of a mixture of K2Ti4O9 and K2Ti6O13. The temperature of decomposition and the identity of the products of the thermal decomposition of K2Ti8Ol7, K2Ti4O9, K2Ti2O5, and K4Ti3O8 were determined by Raman spectroscopy. The XRD data of the newly identified compounds are reported.

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ROY, SOUMYENDU, REETI BAJPAI, K. S. HAZRA, PADMNABH RAI, N. KULSRESTHA, and D. S. MISRA. "CONTROLLED GROWTH OF SEMICONDUCTING SINGLE-WALL CARBON NANOTUBE." International Journal of Nanoscience 10, no. 01n02 (February 2011): 35–38. http://dx.doi.org/10.1142/s0219581x11007624.

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SWCNT was synthesized by catalytic thermal CVD using Fe–Mo and Co–Mo bimetallic catalysts supported by MgO . The nanotubes were studied by SEM and HRTEM microscopy, thermogravimetric analysis, and Raman spectroscopy. The chiralities of the tubes were established from their Raman spectra using Kataura plot. The Raman shifts for the Co-catalyzed nanotubes were found to lie in the semiconducting region.

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44

Liu, Jing, Pei Li, and Hongsheng Zheng. "Review on Techniques for Thermal Characterization of Graphene and Related 2D Materials." Nanomaterials 11, no. 11 (October 21, 2021): 2787. http://dx.doi.org/10.3390/nano11112787.

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The discovery of graphene and its analog, such as MoS2, has boosted research. The thermal transport in 2D materials gains much of the interest, especially when graphene has high thermal conductivity. However, the thermal properties of 2D materials obtained from experiments have large discrepancies. For example, the thermal conductivity of single layer suspended graphene obtained by experiments spans over a large range: 1100–5000 W/m·K. Apart from the different graphene quality in experiments, the thermal characterization methods play an important role in the observed large deviation of experimental data. Here we provide a critical review of the widely used thermal characterization techniques: the optothermal Raman technique and the micro-bridge method. The critical issues in the two methods are carefully revised and discussed in great depth. Furthermore, improvements in Raman-based techniques to investigate the energy transport in 2D materials are discussed.

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45

Piazza, Aurora, Filippo Giannazzo, Gianpiero Buscarino, Gabriele Fisichella, Antonino La Magna, Fabrizio Roccaforte, Marco Cannas, Franco Mario Gelardi, and Simonpietro Agnello. "In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS2 in O2-controlled atmosphere." Beilstein Journal of Nanotechnology 8 (February 10, 2017): 418–24. http://dx.doi.org/10.3762/bjnano.8.44.

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The effects of temperature and atmosphere (air and O2) on the doping of monolayers of graphene (Gr) on SiO2 and Si substrates, and on the doping of MoS2 multilayer flakes transferred on the same substrates have been investigated. The investigations were carried out by in situ micro-Raman spectroscopy during thermal treatments up to 430 °C, and by atomic force microscopy (AFM). The spectral positions of the G and 2D Raman bands of Gr undergo only minor changes during treatment, while their amplitude and full width at half maximum (FWHM) vary as a function of the temperature and the used atmosphere. The thermal treatments in oxygen atmosphere show, in addition to a thermal effect, an effect attributable to a p-type doping through oxygen. The thermal broadening of the line shape, found during thermal treatments by in situ Raman measurements, can be related to thermal phonon effects. The absence of a band shift results from the balance between a red shift due to thermal effects and a blue shift induced by doping. This shows the potential of in situ measurements to follow the doping kinetics. The treatment of MoS2 in O2 has evidenced a progressive erosion of the flakes without relevant spectral changes in their central zone during in situ measurements. The formation of MoO3 on the edges of the flakes is observed indicative of the oxygen-activated transformation.

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46

Ki, Ra-Seong, Kwang-Seok Seo, and Ho-Young Cha. "Thermal Boundary Resistance Extraction of GaN-on-Diamond Substrate from Transmission Line Method Pattern Using Micro-Raman Spectroscopy and Thermal Simulation." Journal of Nanoscience and Nanotechnology 21, no. 8 (August 1, 2021): 4434–37. http://dx.doi.org/10.1166/jnn.2021.19414.

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Heat dissipation properties are very important in AlGaN/GaN RF high electron mobility transistor (HEMT) devices operating at high frequency and high power. Therefore, in order to extract the thermal conductivity of the substrate and device, which are essential for the analysis of the heat dissipation characteristics, various methods of extraction were attempted. And this experiments were conducted in parallel with micro-raman measurement and thermal simulation. As a result, it was possible to extract the thermal conductivity of each GaN-on-diamond epi layer by matching the thermal simulation data and the shift of the micro-raman peak according to various operating states and temperatures of the transmission line method (TLM) pattern. In particular, we tried to extract the thermal boundary resistance (TBR) of the interface layer (SiNx) for adhesion between GaN and diamond, which greatly affects the thermal conductivity of the device, and successfully extracted the following thermal conductivity value of KTBR = 3.162·(T/300)−0.8 (W/mK) from GaN and diamond interface layer.

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47

Paprzycka, Małgorzata, Błażej Scheibe, and Stefan Jurga. "Fish Collagen – Molecular Structure After Thermal Treatment." Fibres and Textiles in Eastern Europe 26, no. 6(132) (December 31, 2018): 51–56. http://dx.doi.org/10.5604/01.3001.0012.5170.

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Modern medicine widely uses exogenous collagen as a good material for tissue regeneration, also as a natural substrate for cell attachment and proliferation, used to create dressings and to support the treatment of burn and diabetic wounds, or finally as a source of amino acids in the form of a dietary supplement. Collagen is a safe material that has high biocompatibility and biodegradability as well as good cell adhesion. Due to the possibility of transferring Creutzfeld-Jacob’s disease (Bovine Spongiform Encephalopathy) from animals to the human body, interest in collagen from fish is currently increasing. The collagen we examined was derived from the skin of the silver carp fish (Hypophtalmichthys molitrix) and was obtained by the method of hydration in an aqueous lactic acid solution. The topography of the test sample was performed with the AFM method, showing its fibrillar structure with dimensions equivalent to those given in iterature. Raman spectroscopy was used to study fish collagen using a Renishaw Ramanscope with a helium-neon laser at a wavelength of 633 nm. Analysis of Raman spectra allowed to determine the content of amino acids in collagen, as well as glycine, proline and hydroxyproline. It also showed the native nature of the material at 20 °C. The partial renaturation of the secondary structure of this material heated to about 85 °C and cooled was also proved. Raman spectroscopy has been presented as an effective method for testing biopolymers.

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48

M K, Ranjuna, and Jayakumar Balakrishnan. "Investigating the thermal transport in gold decorated graphene by opto-thermal Raman technique." Nanotechnology 33, no. 13 (January 7, 2022): 135706. http://dx.doi.org/10.1088/1361-6528/ac45c2.

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Abstract We report a systematic study on the thermal transport properties of gold nanoparticles (Au NPs) decorated single-layer graphene on a SiO2/Si substrate by the opto-thermal Raman technique. Our results, with moderate Au NPs coverage (<10%), demonstrate an enhancement in the thermal conductivity of graphene by ∼55% from its pristine value and a decrement in the interface conductance by a factor of 1.5. A detailed analysis of our results shows the importance of the photo-thermal conversion efficiency of Au NPs, plasmon–phonon coupling and lattice modifications in the graphene developed after gold nanoparticles deposition in enhancing the thermal conductivity and reducing the interface thermal conductance of the system. Our study paves way for a better understanding of the thermal management in such hybrid systems, which are envisioned as excellent candidates for optoelectronics and photonics applications.

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49

Ma, C. Y., M. K. Rout, and D. L. Phillips. "Study of Thermal Aggregation and Gelation of Oat Globulin by Raman Spectroscopy." Spectroscopy 17, no. 2-3 (2003): 417–28. http://dx.doi.org/10.1155/2003/752027.

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Thermal aggregation and gelation of oat globulin were studied by FT-NIR Raman spectroscopy. The buffer-soluble aggregates exhibited a Raman spectrum similar to that of the unheated control, whereas the insoluble aggregates showed intensity increases in the tryptophan, C–H bending and C–H stretching bands, and a decrease in the tyrosine doublet (I850/I830), suggesting protein denaturation. However, analysis of the amide I region using Raman Spectral Analysis Package (RASP) program revealed marked decreases inα-helical and increases inβ-sheet structure in both soluble and insoluble aggregates. Similar conformational changes were also observed in the heat-induced oat globulin gels, and may be attributed to realignment of molecular segments and formation of intermolecularβ-sheet structures. Thermal gelation under the influence of different chaotropic salts showed some shifts in band positions and changes in band intensity, following the lyotropic series of anions. Several protein structure perturbants, including sodium dodecyl sulfate, dithiothreitol, urea and sodium laurate, were found to affect the Raman spectral characteristics of oat globulin gels. The data suggest that changes in gelling properties of oat globulin by these chemicals may be related to conformational changes of the protein during gelation.

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50

Balzaretti, Naira M., Albert Feldman, Edgar S. Etz, and Roy Gat. "Growth-rate dependence of the thermal conductivity of chemical-vapor-deposited diamond." Journal of Materials Research 14, no. 9 (September 1999): 3720–24. http://dx.doi.org/10.1557/jmr.1999.0502.

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The in-plane thermal diffusivity of chemical-vapor-deposited diamond films was measured as a function of diamond-growth rate. The films, 0.1–0.4 mm thick, were prepared in microwave-plasma reactor at growth rates ranging from 1 to 10 μm/h. A modification of Ångstöm's method was used to perform the diffusivity measurements. The thermal conductivity calculated from the thermal diffusivity shows an inverse relationship with growth rate. Analyses of Raman spectra indicate that both the line shifts and the line widths of the diamond Raman peak are practically independent of the deposition rate, except for the specimen grown at the highest growth rate.

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