Raman microprobe characterization

Raman Microspectroscopy. Raman spectra of small soflds or small regions of soflds can be obtained at a spatial resolution of about 1 p.m usiag a Raman microprobe. A widespread appHcation is ia the characterization of materials. For example, the Raman microprobe is used to measure lattice strain ia semiconductors (30) and polymers (31,32), and to identify graphitic regions ia diamond films (33). The microprobe has long been employed to identify fluid iaclusions ia minerals (34), and is iacreasiagly popular for identification of iaclusions ia glass (qv) (35). 

Figure 3-8 Raman microprobe spectrum of fluorinated hydrocarbon contaminant on silicon wafer that had been polished and plasma-etched (lower) and Raman spectrum of polytetrafluoro-ethylene (upper). Laser, 135 mW at 514.5 nm. Slits, 300 jon. Time, 0.5 s per data point. (Reproduced with permission from Adar, F., in Microelectronics Processing Inorganic Materials Characterization (L. A. Casper, ed.), ACS Symposium Series Vol. 295, pp. 230-239. American Chemical Society, Washington, D.C., 1986. Copyright 1986 American Chemical Society.)...

Characterization thus involves analytical electron microscopy, ordinary microprobe analysis or other techniques for localizing elements or chemical compounds (Scanning Auger Spectroscopy, Raman Microprobe, Laser Microprobe Mass Spectrometry). It also requires, in most cases, some physical separation of the catalyst for separate analysis (e.g., near surface parts and center of pellets, by peeling or progressive abrasion pellets present at various heights in the catalyst bed, etc.). 

Optical Fibers. Several manufacturers of optical fibers have suggested that a Raman microprobe could be a useful tool in characterizing fibers. The literature shows that it is possible to monitor the concentration of additives to silica down to the 1 mole percent level, f 13-17) Polished sections of preforms or drawn fibers have been monitored in the microprobe in this laboratory. 

WoPENKA B. and Pasteris J. D. (1993) Structural characterization of kerogens to granulite-facies graphite applicability of Raman microprobe spectroscopy. Am. Mineral. 78, 533-557. 

Atalla, R.H. Raman spectroscopy and Raman microprobe Valuable new tools for characterizing wood and wood pulp fibers. J. Wood Chem. Technol. 7, 115-131 (1987)... 

An important development in Raman spectroscopy has been the coupling cf the spectrometer to an optical microscope. This allows the chemical and structural analysis described above to be applied to sample volumes only 1 across [38]. No more sample preparation is required than that for optical microscopy, and the microscope itself can be used to locate and record the area which is analyzed. This has obvious practical application to the characterization of small impurities or dispersed phases in polymer samples. This instrument, which may be called the micro-Raman spectrometer, the Raman microprobe or the Molecular Optics Laser Examiner [39] has also been applied to the study of mechanical properties in polymer fibers and composites. It can act as a non-invasive strain gauge with 1 fim resolution, and this type of work has recently been reviewed by Meier and Kip [40]. Even if the sample is large and homogeneous, there may be advantages in using the micro-Raman instrument. The microscope... 

DRIFT, were used to characterize surface species on alumina and kaolin. A Raman microprobe was capable of obtaining spectra from a very small area (2 pm... 

A) Fiber with dye (B) Fiber only, after solvent extraction of dye (C) Dye spectrum obtained by computer subtraction of B from A. Reproduced with permission from Keen, I. R, etal. "Characterization of Fibers by Raman Microprobe Spectroscopy. " Journal of Forensic Sciences 43 (7998j, 82- 9. Copyright 1998, ASTM International. 

Keen, L P., et al. "Characterization of Fibers by Raman Microprobe Spectroscopy." Journal of Forensic Sciences 43 (1998), 82-89. 

DR Clarke, F Adar. Raman microprobe spectroscopy of polyphase ceramics. In DR Rossington, RA Condrate, RL Synder, eds. Advances in Materials Characterization. Materials Science Research Volume 15. New York Plenum Press, 1983, pp. 199-214. 

Figure 19 Specific area of the D band approximated by the area of the D peak over sum of the areas of the D and G peaks, multiplied by 100, versus the in-plane crystallite size of La in angstroms. Points are for anthracene, thin and thick C films, and the Tuinstra and Koenig correlation for comparison [55]. (Reproduced from American Mineralogist, 78, Wopenka, B., et al., Structural characterization of kerogens to granulite-facies graphite Applicability of Raman microprobe spectroscopy, pp. 533-557. Copyright 1993, with permission from American Mineralogical Society.)...

Physical and chemical characterization methods are essential to assess aspects such as material and processing quality. Raman microprobe is an analytical tool coupled to an optical microscope. Elemental analysis using the x-rays emitted from the specimens in the electronic microscopy techniques can be used for local composition determination or to obtain a map of the distribution of a certain element in a wider area wavelength and energy-dispersive x-ray spectrometers are used for these purposes. Fourier transform infrared spectrometer is widely used for the qualitative and quantitative analysis of adhesives, the identification of unknown chemical compounds, and the characterization of chemical reactions. Thermal methods such as thermomechanical analysis and differential scanning calorimetry are discussed as valuable tools for obtaining information during postfracture analysis of adhesively bonded joints. 

Physical and chemical characterization methods are essential to assess aspects such as material and processing quality. Chemical microanalysis - Raman microprobe coupled to an optical microscope and x-ray spectrometers in electronic microscopes - is applied to determine the elemental composition of a small region or it can be used to show the distribution of a particular element in a wide area of the specimen. 

In the present work wet chemistry methods of preparing silver nanoparticles reduced with different chemical agents including sodium citrate and hydroxylamine hydrochloride were discussed. Methodologies used for characterization of the nanoparticles were UV-VIS spectrophotometry, SEM and TEM images and X-Ray Microprobe Fluorescence. Fin y, the metallic sols were tested for SERS activity using vahdated test compounds that exhibit strong Raman enhancements in the presence of the nanoparticles. 

Bulk characterization tools. The formation of nanostructured AIN powders have been confirmed by FT-IR spectroscopy (Nicolet 60SX), Raman spectrometry (Dilor microprobe). X-ray diffraction (XRD) (Norelco X-ray diffraction unit with wide range goniometer), and transmission electron microscopy (TEM), along with the corresponding electron diffraction in a JEOL 200CX microscope. 

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