Limits...
Synthesis of nanocrystals by discharges in liquid nitrogen from Si-Sn sintered electrode.

Kabbara H, Noël C, Ghanbaja J, Hussein K, Mariotti D, Švrček V, Belmonte T - Sci Rep (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Université de Lorraine, Institut Jean Lamour, UMR CNRS 7198, NANCY, F-54042, France.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Proposed growth mechanism explaining how the Si0.95Sn0.05 phase at the edges of large silicon crystals (~500 nm) decorated by β–Sn spheroids are synthesized by high intensity discharges.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664926&req=5

f7: Proposed growth mechanism explaining how the Si0.95Sn0.05 phase at the edges of large silicon crystals (~500 nm) decorated by β–Sn spheroids are synthesized by high intensity discharges.

Mentions: When the ballast resistance is only 1 kΩ, the current is 10 A and spark discharges are much stronger. The erosion mechanism of the sintered target is then completely different. Synthesis of Si0.95Sn0.05 in large silicon crystals (~500 nm) decorated by β–Sn spheroids is achieved as described in Fig. 7. To our knowledge, this latter mechanism is the first of its kind ever described. When the discharge hits the sintered material, very large grains of silicon decorated by tin spheroids are heated. Diffusion of tin in silicon is activated and the amorphous layer, made of Si0.95Sn0.05 around the silicon grain is synthesized. Because the discharge is very powerful, thermal gradients are likely strong enough to induce sufficient stress to shell the crystals. Moreover, the mean size of the loose particles collected in these conditions corresponds to that of silicon grains in the target, i.e. the sintered material. Then, it is important to stress here that alloying is achieved and permits the synthesis of a small amount of Si1–xSnx surrounding large silicon crystals and decorated by tin nanoparticles.


Synthesis of nanocrystals by discharges in liquid nitrogen from Si-Sn sintered electrode.

Kabbara H, Noël C, Ghanbaja J, Hussein K, Mariotti D, Švrček V, Belmonte T - Sci Rep (2015)

Proposed growth mechanism explaining how the Si0.95Sn0.05 phase at the edges of large silicon crystals (~500 nm) decorated by β–Sn spheroids are synthesized by high intensity discharges.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664926&req=5

f7: Proposed growth mechanism explaining how the Si0.95Sn0.05 phase at the edges of large silicon crystals (~500 nm) decorated by β–Sn spheroids are synthesized by high intensity discharges.
Mentions: When the ballast resistance is only 1 kΩ, the current is 10 A and spark discharges are much stronger. The erosion mechanism of the sintered target is then completely different. Synthesis of Si0.95Sn0.05 in large silicon crystals (~500 nm) decorated by β–Sn spheroids is achieved as described in Fig. 7. To our knowledge, this latter mechanism is the first of its kind ever described. When the discharge hits the sintered material, very large grains of silicon decorated by tin spheroids are heated. Diffusion of tin in silicon is activated and the amorphous layer, made of Si0.95Sn0.05 around the silicon grain is synthesized. Because the discharge is very powerful, thermal gradients are likely strong enough to induce sufficient stress to shell the crystals. Moreover, the mean size of the loose particles collected in these conditions corresponds to that of silicon grains in the target, i.e. the sintered material. Then, it is important to stress here that alloying is achieved and permits the synthesis of a small amount of Si1–xSnx surrounding large silicon crystals and decorated by tin nanoparticles.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Université de Lorraine, Institut Jean Lamour, UMR CNRS 7198, NANCY, F-54042, France.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus