Abstract

Interferometric infrared spectral transmission measurements from 60 to 10 000 cm⁻¹ were made for thin films of NH₃, NH₄HS, and H₂S cryodeposits, and recorded as a function of thickness and temperature from 88 K to evaporation points. Integrated band intensities were measured and are reported for all major absorptions. Assignments for lattice and internal fundamental modes are discussed. Particular attention is devoted to the various reported phases of solid NH₃, and it is concluded that three phases are supported by experimental evidence: the stable cubic phase, a low temperature amorphous phase, and an intermediate temperature metastable phase. Results and changes of the spectra as a function of temperature will be summarized. Intercomparisons of the spectra obtained for the three cryodeposits are made.

Absorption coefficients of solid NH₃ from 50 to 7000 cm⁻¹

Godfrey Sill, Uwe Fink, and John R. Ferraro
J. Opt. Soc. Am. 70(6) 724-739 (1980)

Infrared optical properties of thin H₂O, NH₃, and CO₂ cryofilms

B. E. Wood and J. A. Roux
J. Opt. Soc. Am. 72(6) 720-728 (1982)

CO₂ Laser Absorption Coefficients for Determining Ambient Levels of O₃, NH₃, and C₂H₄

R. R. Patty, G. M. Russwurm, W. A. McClenny, and D. R. Morgan
Appl. Opt. 13(12) 2850-2854 (1974)

Temperature and pressure dependence of NH₃ and C₂H₄ absorption cross sections at CO₂ laser wavelengths

U. Persson, B. Marthinsson, J. Johansson, and S. T. Eng
Appl. Opt. 19(10) 1711-1715 (1980)

High-Resolution Stark Spectroscopy in the ν₄ Band of NH₃ Using a Thin-Film Diode Laser

W. H. Weber, P. D. Maker, K. F. Yeung, and C. W. Peters
Appl. Opt. 13(6) 1431-1434 (1974)