Search results for "silicate glasse"
showing 3 items of 3 documents
OH-related Infrared Absorption Bands in Oxide Glasses
2005
We report the infrared activity, in the spectral region of the OH stretching modes, of different composite silicate glasses whose chemical composition is established by X-ray fluorescence measurements. The analysis of the absorption line profiles is made in terms of different spectral contributions, Gaussian in shape. The comparison with analogous spectra obtained in vitreous silica samples with impurity concentrations < 100 part per million moles is evidence of the effects of the different oxides on the vibrational properties of the OH groups. In particular, for oxide glasses a red shift of the composite band at about 3670 cm(-1), assigned to the OH stretching modes of free Si-OH groups an…
Electron microprobe technique for the determination of iron oxidation state in silicate glasses
2018
We present a new calibration for the determination of the iron oxidation state in silicate glasses by electron probe microanalysis (EPMA) with the "flank method." This method is based on the changes in both intensity and wavelength of the FeLα and FeLβ X-ray emission lines with iron oxidation state. The flank method utilizes the maximum difference for the FeLα and FeLβ spectra observed at the peak flanks between different standard materials, which quantitatively correlates with the Fe2+ content. Provided that this correlation is calibrated on reference materials, the Fe2+/ΣFe ratio can be determined for samples with known total Fe content. Two synthetic Fe-rich ferric and ferrous garnet end…
Near‐IR Radiation‐Induced Attenuation of Aluminosilicate Optical Fibers
2021
The X-ray radiation-induced attenuation (RIA) growth kinetics are studied online in different single-mode aluminosilicate optical fibers in the near-IR (NIR) domain to evaluate their potential in terms of dosimetry. The optical fibers differ by Al contents, core sizes, drawing parameters, and also by a preform deposition process. The data show no dependence of the RIA on all these parameters, a positive result for the design of point or distributed radiation detectors exploiting RIA to monitor the dose. The RIA growth rate is unchanged for dose rates changing from 0.073 to 6.25 Gy(SiO2) s−1, and the RIA linearly increases with the dose up to 2 kGy(SiO2). Small but noticeable RIA changes are…