FT-IR spectra of silicate glasses methods of computer processing

The present work revealed that with the help of the appropriate conduced mathematical procedure one can obtain important information concerning silicate glass structure. Most of this information is not available directly from the original spectra. The proposed way of spectra interpretation is based on two processes: decomposition of the complex envelope of spectra into separate peaks and summation of the spectra. Both procedures were realized with the help of computer programme SpectraCalc. The spectra decomposition was based on: 1) the rule of minimization of the bands number, 2) analyzing the second derivative of the spectrum, 3) Fourier self deconvolution of the spectra, 4) comparing with the spectra of the crystalline analogues. According to the procedure proposed, the spectra of the crystalline and glassy analogous of the following substances were decomposed: SiO2 (silica), K[AlSi2O6] (leucite) and Li[AlSi2O6] (spodumene). It has been proved that apart the bands corresponding to the crystalline substances in the spectra of glasses there occur the bands responsible for specific features of the glassy structure. Summation of spectra has been illustrated by taking the spectrum Li[AlSi3O8] (lithium orthoclase) as example. Thanks to this procedure has been found that this compounds consisting the constituting the kind of solid solution of lithium aluminosilicates both in the glassy and crystalline phases. (author). 12 refs, 4 figs