Infrared optical constants of H2O ice, amorphous nitric acid solutions, and nitric acid hydrates

We determined the infrared optical constants of nitric acid trihydrate, nitric acid dihydrate, nitric acid monohydrate, and solid amorphous nitric acid solutions which crystallize to form these hydrates. We have also found the infrared optical constants of H2O ice. We measured the transmission of infrared light through thin films of varying thickness over the frequency range from about 7000 to 500 cm−1 at temperatures below 200 K. We developed a theory for the transmission of light through a substrate that has thin films on both sides. We used an iterative Kramers-Kronig technique to determine the optical constants which gave the best match between measured transmission spectra and those calculated for a variety of films of different thickness. These optical constants should be useful for calculations of the infrared spectrum of polar stratospheric clouds.

[1]  S. Tsujimoto,et al.  Optical constants and thermal radiative properties of CO2 cryodeposit , 1982 .

[2]  J. Pearl,et al.  Optical constants of solid methane and ethane from 10,000 to 450 cm−1 , 1991 .

[3]  Steven M. George,et al.  Refractive Indices of Amorphous and Crystalline HNO3/H2O Films Representative of Polar Stratospheric Clouds , 1994 .

[4]  K. F. Palmer,et al.  Determination of the optical constants of a thin film from transmittance measurements of a single film thickness. , 1985, Applied optics.

[5]  M. Querry,et al.  Reflectance and complex refractive indices in the infrared for aqueous solutions of nitric acid , 1980 .

[6]  John E. Bertie,et al.  Absorptivity of Ice I in the Range 4000–30 cm−1 , 1969 .

[7]  L. F. Keyser,et al.  Infrared spectra of solid films formed from vapors containing water and nitric acid , 1991 .

[8]  R. Khanna,et al.  Absorption intensities and complex refractive indices of crystalline HCN, HC3N, and C4N2 in the infrared region , 1990 .

[9]  J. Devlin,et al.  Infrared spectra of nitric and hydrochloric acid hydrate thin films , 1991 .

[10]  P. Nilsson.  Determination of optical constants from intensity measurements at normal incidence. , 1968, Applied optics.

[11]  Dudley A. Williams,et al.  Optical constants of ice in the infrared , 1973 .

[12]  Owen B. Toon,et al.  The optical constants of several atmospheric aerosol species: Ammonium sulfate, aluminum oxide, and sodium chloride , 1976 .

[13]  S. Warren,et al.  Optical constants of ice from the ultraviolet to the microwave. , 1984, Applied optics.

[14]  A. Middlebrook,et al.  Characterization of model polar stratospheric cloud films using Fourier transform infrared spectroscopy and temperature programmed desorption , 1992 .

[15]  W. Suëtaka,et al.  Optical Constants of Thin Films by a Kramers–Kronig Method , 1966 .

[16]  A. Middlebrook,et al.  Fourier transform infrared studies of model polar stratospheric cloud surfaces : growth and evaporation of ice and nitric acid/ice , 1990 .

[17]  S. Rice,et al.  The OH stretching region infrared spectra of low density amorphous solid water and polycrystalline ice Ih , 1978 .

[18]  Dudley H. Williams,et al.  Optical constants of water in the infrared , 1975 .

[19]  U. Fink,et al.  Absorption coefficients of solid NH 3 from 50 to 7000 cm −1 , 1980 .

[20]  H. Verleur,et al.  Determination of Optical Constants from Reflectance or Transmittance Measurements on Bulk Crystals or Thin Films , 1968 .

[21]  A. Middlebrook,et al.  Real refractive indices of infrared-characterized nitric-acid/ice films: Implications for optical measurements of polar stratospheric clouds , 1994 .