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Raman Study of Arsenic‐Containing Potassium Silicate Glasses
Author(s) -
VERWEIJ H.
Publication year - 1981
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1981.tb09904.x
Subject(s) - potassium silicate , raman spectroscopy , silicate , arsenate , analytical chemistry (journal) , potassium , ion , arsenic , spectral line , arsenite , materials science , chemistry , mineralogy , optics , metallurgy , physics , organic chemistry , chromatography , astronomy
Raman spectra are given of potassium silicate glasses with batch composition x K 2 CO 3 ‐(100— x )SiO 2 ‐0.5As 2 O 3 in which x varies from 10 to 50. To isolate the contribution of the As 2 O 3 additions to the spectra from that of the silicate network, difference spectra were prepared from spectra of glasses with and without As 2 O 3 added to the batch. To obtain a precision sufficient for this purpose, the spectral data were collected in multiple scans under full computer control using photon counting and a correction for laser‐source fluctuations. It is concluded from the polarized and depolarized difference spectra that arsenic in potassium silicate glasses with x >35 is mainly present in the pentavalent state as AsO 4 3 ‐ ions. For glasses with x <35 it is concluded that As 5+ is present in As 2 O 7 4 ‐ or As 3 O 10 5 ‐ ions and As 3+ as As m O 2m+1 ‐ m ‐ 2 chains of AsO 3 pyramids. In these chains, m increases with decreasing x . From the intensity ratio of Raman peaks, caused by arsenite (As 3+ ) and arsenate (As 5+ ) ions in the glasses, it is concluded that there is a significant increase of the As 3+ /As 5+ ratio with x increasing from 50 to 10. The effect of melting temperature on the As 3+ /As 5+ ratio in 30K 2 O‐70SiO 2 ‐0.5As 2 O 3 glasses at 1300° to 1600°C was also studied. No clear temperature effect could be concluded from the Raman spectra.