Dispersion analysis of FTIR reflection measurements in silicate glasses

Infrared reflection spectra from alkali silicate glasses exposed to water for various times are analyzed using several causal methods, based on Kramers-Kronig (KK) relations between the real and imaginary parts of the dielectric functions. The results show that use of causal Gaussian dispersion equations works well in producing peaks in the imaginary component of the dielectric function that remain fixed in wavelength position and width during a surface leaching process. This allows accurate definition of the behavior of associated composition and structural changes in the glass surface. This method is suggested for non-destructive surface analysis of materials. (C) 2000 Elsevier Science B.V. All rights reserved.