8 research outputs found
Mercury thioarsenate glasses: a hybrid chain/ pyramidal network
No full textInternational audienceVery little is known about mercury chalcogenide glasses. Using Raman spectroscopy and DFT modelling, we show that the (HgS)x(As2S3)1-x glasses, 0.0 ≤ x ≤ 0.5, form a hybrid Hg–S chain/As–S pyramidal network, highly unusual for metal chalcogenide glasses. This network is evidenced by Hg–S stretching modes at 300 and 370 cm-1 and an As–S spectral envelope centred at 340 cm-1. The decreasing glass transition temperature is consistent with a gradual substitution of more rigid corner-sharing CS-AsS3/2 pyramids by flexible (HgS2/2)n chain fragments. Nevertheless we cannot exclude completely the presence of a small fraction of HgS4/4 tetrahedral units. A non-monotonic change in electronic transport properties and metacinnabar ß-HgS traces detected using neutron diffraction in large x = 0.5 samples support the dual structural role of mercur
One-step direct synthesis of nano bismuth vanadate from bismuth oxide and sodium metavanadate via liquid phase ball-milling method: A novel and environmentally friendly process
No full textElectrochemical preparation of uniform CuO/Cu2O heterojunction on β-cyclodextrin-modified carbon fibers
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A novel two-stage discrete crack method based on the screened Poisson equation and local mesh refinement
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