New Protonated Thioborate Glasses in the xH2S + (1 − x)B2S3 Series

Abstract

<p>A new series of anhydrous protonated chalcogenide glasses, <em>x</em>H2S + (1 − <em>x</em>)B2S3, analogous to alkali-modified glasses, have been prepared. The preparation of these glasses was carried out in multiple steps. First crystalline <em>meta</em>-thioboric acid, <em>c</em>-(HBS2)3, was prepared from vitreous boron sulfide, <em>v</em>-B2S3. <em>c</em>-(HBS2)3 was then used as a precursor for protonation to prepare a series of <em>x</em>H2S + (1 − <em>x</em>)B2S3 samples with 0.0 ≤ <em>x</em> ≤ 0.5. The glass formation region of this system was found to be 0.0 ≤ <em>x</em> ≤ 0.25. The density and glass-transition temperature (<em>T</em>g) of the samples were measured. While a substantial decrease in <em>T</em>g of the protonated glasses has been observed, there are insignificant changes in the density of the glasses. The IR and NMR spectra of the samples in the region 0.0 ≤ <em>x</em> ≤ 0.5 suggest that no tetrahedral borons are formed with the incorporation of protons. The characterization shows that these materials are unique and exhibit no borate anomaly as in the alkali-modified glasses.</p>