Molecular and crystalline electromagnetic properties of selected condensed materials in the infrared

By using water as a reflectance standard, relative specular reflectance spectra in the infrared were measured for 38 materials including aqueous solutions of zinc chloride, phosphoric acid, and nitric acid, and for diesel fuel, fog oil, tetramethyl-tetraphenyl-trisiloxane, l-hexadecanol, l-octadecanol, l-eicosanol, rutile, lucite, limestone, and natural waters. Spectral values of the complex refractive indices, suitable for Mie scattering computations, were computed and tabulated by use of Kramers-Kronig analysis. The spectra were further analyzed in terms of fundamental intra and inter-molecular vibrational modes. Transmittance spectra of powders pressed in a KBr matrix were also measured. Powders were montmorillonite, colemanite, Kernite, Kaolin, Lampblack, activated charcoal, and wood charcoal. Analysis of the transmittance spectra was not completed but is still underway during continuation of this research. Tabulations of all complex refractive indices were supplied to the Aerosol/Obscuration Science Group at the Aberdeen Proving Ground, Md.