[Optical properties research of NH4NO3 by Fourier transform infrared spectroscopy].

In the present paper, the infrared spectrum of aerosol and NH4 NO3 was analysed and compared, and the result showed that the infrared spectral features of aerosol are consistent with that of NH4 NO3. The absorption coefficient alpha and the mass absorption cross section kappa of NO3- was calculated by the transmissivity of NO3- in NH4 NO3 according to Beer-Lambert law. Then the imaginary part of the complex refractive index was calculated through alpha. The real part of the complex refractive index was derived from the K-K(Kramers-Kroning) relationship. It has important significance for further research on the scattering and absorption characteristics of the different composition of the atmospheric aerosol through analysing the results of the experiment.