Synthesis of nanocrystals by discharges in liquid nitrogen from Si-Sn sintered electrode.
Fiche publication
Date publication
décembre 2015
Journal
Scientific reports
Auteurs
Membres identifiés du Cancéropôle Est :
Dr BELMONTE Thierry
Tous les auteurs :
Kabbara H, Noël C, Ghanbaja J, Hussein K, Mariotti D, Švrček V, Belmonte T
Lien Pubmed
Résumé
The synthesis feasibility of silicon-tin nanocrystals by discharges in liquid nitrogen is studied using a Si-10 at % Sn sintered electrode. Time-resolved optical emission spectroscopy shows that silicon and tin melt almost simultaneously. The presence of both vapours does not lead to the synthesis of alloyed nanocrystals but to the synthesis of separate nanocrystals of silicon and tin with average sizes of 10 nm. These nanocrystals are transformed into amorphous silicon oxide (am-SiO2) and β-SnO2 by air oxidation, after evaporation of the liquid nitrogen. The synthesis of an am-Si0.95Sn0.05 phase around large silicon crystals (~500 nm) decorated by β-Sn spheroids is achieved if the current flowing through electrodes is high enough. When the sintered electrode is hit by powerful discharges, some grains are heated and tin diffuses in the large silicon crystals. Next, these grains are shelled and fall into the dielectric liquid.
Référence
Sci Rep. 2015 Dec 1;5:17477