Infrared analysis of the grossular-hydrogrossular series

Abstract

The infrared absorption spectra of the grossular–hydrogrossular series have been recorded for hydrothermally synthesized materials. The compositions of the prepared materials are Ca₃Al₂(SiO₄)_3−x(O₄H₄)_x (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0). Infrared absorption patterns of these garnets were given by the KBr method in the range of wave number from 4000 cm⁻¹ to 250 cm⁻¹ after drying in a vacuum desiccator with Mg(ClO₄)₂. The results showed a close relation between the spectrum patterns and the amounts of constitutional water in these garnets. The linear relation between the chemical composition and the ratio of logarithmic transmittancy, was observed for 14 pairs of absorption bands and/or transmission ones. This implies the possible use of the infrared absorption method in the determination of the amount of water in garnets of this series.