FTIR studies of BPO4·2SiO2, BPO4·SiO2 and 2BPO4·SiO2 joints in amorphous and crystalline forms

Abstract

The MIR spectra of glasses and devitrificates of BPO4·2SiO2, BPO4 SiO2 and 2BPO4·SiO2 compositions have been shown. The bands arising from the Si–O, B–O and P–O bonds vibrations can be assigned in the spectra of the above samples. All bands appear almost at the same wavenumber range: what causes their coincidence? Therefore, all spectra of crystalline and amorphous materials were decomposed into component bands. The decomposed MIR spectra of these samples, as well as the tetragonal boron orthophosphate BPO4 and the low temperature crystobalite spectra, were then compared. Therefore, one can estimate the probability of the existence of any compounds within the BPO4–SiO2 (P2O5–B2O3–SiO2) system. The presence of BPO4·2SiO2 was reported in a few papers. The results obtained in this work can be treated as an attempt to verify the above hypothesis verifying because of the opposed information existing on this subject in literature.