QUANTITATIVE ASPECTS OF FT-IR EMISSION-SPECTROSCOPY AND SIMULATION OFEMISSION-ABSORPTION SPECTRA

Recent advances in FT-IR emission spectroscopy of solids are briefly r eviewed, and some neglected points concerning the measurement of black body radiation are dealt with. A corrected equation describing the sin gle-beam emission spectra is given, taking into account the possible t hermal radiation of the detector. Similarities between the effect of s elf-absorption and that of ''illegal'' data manipulations on emittance spectra are pointed out, both giving rise to spectral distortions lik e inverted or split peaks or altered band shapes and intensities. To a void some of these problems, the use of a linear emission intensity sc ale, emissivity, is advocated, especially for quantitative work. A spe cial case of self-absorption, namely, that of multilayer samples, is d iscussed, in which the spectral distributions of emitted and absorbed radiation are significantly different. Simulations of the emission-abs orption spectra observed in such cases are shown to help with spectral and structural interpretation.