Infrared transmitting materials

Table 7.24 Absorption Frequencies of Other Double Bonds Table 7.25 Absorption Frequencies of Aromatic Bands Table 7.26 Absorption Frequencies of Miscellaneous Bands Table 7.27 Absorption Frequencies in the Near Infrared Table 7.28 Infrared Transmitting Materials...

The compounds of groups IIB-IVB are often prepared in poiycrystaliine form as phosphors, catalysts (15.2.2.2) and infrared transmitting materials. Their use as semiconductors is almost exclusively for optoelectronic purposes (i.e., light emission and detection). Thus the phosphor preparation technology has relevance to preparation of these semiconductors in powder form. The most common reactions employed are... 

Table 16.6 hsts the properties of several infrared transmitting materials. The short pathlengths required in infrared spectrometry are difficult to reproduce, especially when the windows must be repolished, and so quantitative analysis is not... 

Typically the thin films are made by deposition of a known amount of protein dissolved in a relatively high vapor pressure solvent such as water on a circular window of infrared-transmitting material (see below). Frequently, the next step is to remove some fraction of the solvent in order... 

Cells for holding samples, or windows within the spectrometer must be made of infrared transmitting material. Table 2.1 lists approximate low wavenumber transmission limits for some optical materials used in infrared spectroscopy. All the materials listed transmit in the mid-IR above the transmission limit except for polyethylene, which is used below 600 cm" only, as it has absorption bands at higher frequencies. The transmission limits are not sharply defined and depend somewhat on the thickness of the material used. For example, a typical cell for liquid samples which is made of NaCl... 

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