Reflection Absorption IR Spectroscopy RAIRS

Reflection-Absorption IR spectroscopy (RAIRS) where the linearly polarized IR beam is specularly reflected from the front face of a highly reflective sample, such as a metal single crystal surface (Figure 3.1(a)). This is also sometimes referred to as IRAS (IR reflection absorption). The IR beam comes in at grazing angle (i.e. almost parallel to the surface), and although absorption bands in RAIRS have intensities that are some two orders of magnitude weaker than in transmission studies on... 

Fig. 8.10 Reflection absorption infrared spectroscopy (RAIRS) spectra show that lateral interactions force CO to leave the twofold adsorption sites on palladium (IR frequency ca. 1920 cm-1) when NO is coadsorbed, and push it to the on top site (adsorption frequencies above 2000 cm-1). Adsorbed NO gives rise to the absorption peaks below 1800 cm-1. (Adapted from [35]).

For information on the analysis of surfaces by IR radiation instead of electrons, a complimentary technique known as reflection absorption infrared spectroscopy (RAIRS), see (a) http //www.uksaf.org/tech/rairs.html (b)http //www.cem.msu.edu/ cem924sg/Topicll.pdf For example, the development of fibers/fabrics that will actively adsorb and surface deactivate chemical and biological warfare agents — of increasing importance as new modes of terrorist activity continue to emerge. For more information, see (a) http //web.mit.edu/isn/(Institute of Soldier Nanotechnologies at M.I.T.). (b) Richards, V. N. Vohs, J. K. Williams, G. L. Fahlman, B. D. J. Am. Ceram. Soc. 2005,88,1973. 

For information on the analysis of surfaces by IR radiation instead of electrons, a complimentary technique known as reflection absorption infrared spectroscopy (RAIRS), see (a) http //www.uksaf. orgAech/rairs.html (b) http //www.cem.msu.edu/ cem924sg/Topicll.pdf... 

Infrared external reflection spectroscopy (IR-ERS) is generally based on single external reflection of IR radiation at the surface of a metal or metal film. This method is also called reflection-absorption infrared spectroscopy (RAIRS) or grazing angle... 

One interesting aspect of the application of IR spectroscopy relates to thin (micrometer) and ultrathin (<50 nm) polymer films, polymer surfaces, and polymer-substrate interfaces [23]. So-called external reflection methods can be used to determine the important properties of thin films (comprising monolayers and multilayers) such as thickness, anisotropy, molecular orientation, and composition. The most frequently applied methods include IR ellipsometry (IRE) [63-67] and IR reflection absorption spectroscopy (IRRAS), which may also be referred to as reflection absorption infrared spectroscopy (RAIRS) [1,23]. 

It is possible to monitor vibrational modes below 1000 cm where RAIRS (reflection absorption infrared spectroscopy) has problems with sufficient intensity of the IR source. 

Reflection - Absorption Infrared Spectroscopy. In RAIRS, IR radiation is reflected from a plane surface through an adsorbed layer, the reflected light losing intensity at those frequencies at which the light frequency coincides with a vibrational mode at the surface. The vibrations may be those within the adsorbed species itself, or they may arise from interaction with surface atoms. 

Electronic Absorption and Emission Spectroscopy Visible Spectroscopy Ultraviolet Spectroscopy Luminescence Spectroscopy Electron Spectroscopy Atomic Identification and Analysis Infrared and Raman Spectroscopy Infrared Spectroscopy Infrared Sample Preparation Internal Reflection Spectroscopy (IRS, ATR) Reflection Absorption (RAIR or IRRAS)... 

Figure 2 The optical arrangement of an FT-IR spectrometer for reflection-absorption (RAIRS) work in ultrahigh vacuum (UHV). A, detector B, KBr lens C, KBr window D, UHV chamber E, sample F, Michelson interferometer G, Globar source P, grid polarizer. Reprinted from Chesters MA (1986) Journal of Electron Spectroscopy and Related Phenomena 38 123 Copyright (1986), with permission from Elsevier Science.

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