Determination of Organics on Metal Surfaces by Raman Spectroscopy

1993 ◽  
Vol 47 (11) ◽  
pp. 1767-1771 ◽  
Author(s):  
Ching-Hui Tseng ◽  
Charles K. Mann ◽  
Thomas J. Vickers
Keyword(s):  
Fiber Optic ◽  
Laser Excitation ◽  
Internal Standard ◽  
Aluminum Surface ◽  
Hadamard Transform ◽  
Dimethyl Methylphosphonate ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Detection limits of about 1 g/m2 are demonstrated for the Raman determination of two organic materials, polydimethylsiloxane and dimethyl methylphosphonate, on an aluminum surface. A fiber-optic-based system is used. A large sample area is scanned to overcome heterogeneity in sample coverage. Measurements are made without use of an internal standard. Results are reported for both a Hadamard transform technique with argon-ion laser excitation and a conventional spectrometer with diode laser excitation.

A Study of Measurement Interference in the Optoacoustic Detection of NO2 by Argon-Ion Laser Excitation

1982 ◽  
Vol 36 (5) ◽  
pp. 562-565 ◽  
Author(s):  
Alan Fried
Keyword(s):  
Energy Transfer ◽  
Laser Excitation ◽  
Dramatic Decrease ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Optoacoustic measurements of NO2 excited by an Ar+ laser were performed in the presence of NO, N2, H2O, and O2 matrix gases. Identical sensitivities were measured in all matrix gases except O2 where energy transfer from NO2 to the metastable O2(1Δg) state resulted in a dramatic decrease in sensitivity.

Argon ion laser excitation of supersonic seeded molecular beams of I2

1983 ◽  
Vol 79 (3) ◽  
pp. 321-339 ◽  
Author(s):  
F.J. Aoiz ◽  
M.M. Oprysko ◽  
R.B. Bernstein
Keyword(s):  
Laser Excitation ◽  
Molecular Beams ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Fiber Optic Delivery Of Argon Ion Laser Radiation For Open Endarterectamy

1988 ◽  
Author(s):  
John Eugene ◽  
Joseph S. Carey ◽  
Ramon A. Cukingnan ◽  
Marie Hammer-Wilson ◽  
Michael W. Berns
Keyword(s):  
Laser Radiation ◽  
Fiber Optic ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Determination of Azo Dyes by Resonance-Enhanced Raman Spectroscopy

1987 ◽  
Vol 41 (1) ◽  
pp. 117-119 ◽  
Author(s):  
James D. Womack ◽  
Thomas J. Vickers ◽  
Charles K. Mann
Keyword(s):  
Raman Spectroscopy ◽  
Azo Dyes ◽  
Internal Standard ◽  
Nonlinear Behavior ◽  
Limits Of Detection ◽  
Eriochrome Black T ◽  
Exciting Beam ◽  
Ion Laser ◽  
Argon Ion

An examination of the feasibility of using Raman spectroscopy to determine strongly absorbing solutes has been made, with the use of the azo dyes Eriochrome Blue SE, Eriochrome Black T, and Eriochrome Blue Black B as target compounds. These compounds are representative of the large class of dyes which are not easily determined because of their low volatility. They also are examples of compounds which absorb strongly, causing pronounced nonlinear behavior when attempts are made to use resonance-enhanced bands to improve analytical limits of detection, and which produce intense fluorescence which interferes with Raman bands when the strong 514-nm band of the argon-ion laser is used for excitation. The efficacy of internal standard correction for eliminating the effects of self-reversal and variation in intensity of the exciting beam is demonstrated. Limits of detection for the three compounds listed above are 99 ppb, 340 ppb, and 1.5 ppm, respectively.

Laser Induced Etching for Generation of Si Nanocrystals and Spectroscopic Investigation of Morphology

2005 ◽  
Vol 23 ◽  
pp. 43-46
Author(s):  
H.S. Mavi ◽  
S. Rath ◽  
Arun Shukla
Keyword(s):  
Quantum Confinement ◽  
Silicon Nanocrystals ◽  
Laser Wavelength ◽  
Interconnected Network ◽  
Substrate Type ◽  
Argon Ion Laser ◽  
Si Nanocrystals ◽  
Ion Laser ◽  
Laser Induced Etching ◽  
Argon Ion

Laser-induced etching of silicon is used to generate silicon nanocrystals. The pore structure depends on the substrate type and etching laser wavelength. Porous silicon (PS) samples prepared by Nd:YAG laser (1.16 eV) etching of n-type substrate showed a fairly uniform and highly interconnected network of nearly circular pores separated by thin columnar boundaries, while no circular pits were produced by argon- ion laser (2.41 eV) etching under similar conditions. The size and size distribution of the nanocrystals are investigated by Raman and photoluminescence spectroscopies and analyzed within the framework of quantum confinement models.

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