Determination of Optical Constants of Phosphates, Sulphates and Ammonia and Related Compounds in the Near Infrared Region.

Abstract : A discussion of absorption phenomena in the infrared (2. 5 - 15 micrometers spectral region is presented. Mechanisms surveyed include the attenuation of electromagnetic waves by dielectrics and metals; molecular absorption processes; lattice vibrations in bulk and powdered dielectrics; band gap, free carrier and multiple phonon absorption in semiconductors; absorption in bulk and powdered metals; and absorption by polymeric one-dimensional conductors. Also presented is a review of quantitative methods of determining the optical constants of solids, liquids and gases and their possible sources of error. The results of quantitative absorption measurements on tri-n-butyl phosphate, polymethylmethacrylate, cellulose, polyvinyl alcohol and ureaformaldehyde are included. (Author)