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Fabrication of nanoscale Ga balls via a Coulomb explosion of microscale silica-covered Ga balls by TEM electron-beam irradiation.

Chen Y, Huang Y, Liu N, Su J, Li L, Gao Y - Sci Rep (2015)

Bottom Line: The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of carbon film.The ejected particles in the explosion increase their sizes with increasing irradiation time until the stop of the explosion, but decrease their sizes with increasing distance from the original ball.The Coulomb explosion suggests a novel method to fabricate nanoscale metal particles with low melting point.

View Article: PubMed Central - PubMed

Affiliation: Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074, P. R. China.

ABSTRACT
Nanoscale Ga particles down to 5 nm were fabricated by an explosion via an in situ electron-beam irradiation on microscale silica-covered Ga balls in a transmission electron microscope. The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of carbon film. The ejected particles in the explosion increase their sizes with increasing irradiation time until the stop of the explosion, but decrease their sizes with increasing distance from the original ball. The Coulomb explosion suggests a novel method to fabricate nanoscale metal particles with low melting point.

No MeSH data available.


Related in: MedlinePlus

The relations of the diameter of the ejected Ga balls vs the distance from the center ball to the exploded particles, and the diameter of the Ga balls vs explosion time.(a) The diameters of the exploded particles decrease with increasing distance at the irradiation time of 1158 s; (b) The diameters increase with increasing irradiation time at different distances from the center ball.
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f5: The relations of the diameter of the ejected Ga balls vs the distance from the center ball to the exploded particles, and the diameter of the Ga balls vs explosion time.(a) The diameters of the exploded particles decrease with increasing distance at the irradiation time of 1158 s; (b) The diameters increase with increasing irradiation time at different distances from the center ball.

Mentions: It is found that the distribution of the exploded particles complies with a law during the explosion of microscale Ga balls covered by silica: the size of the exploded particles decreases almost linearly with increasing distance from the center ball, as demonstrated in a case at the moment of 1158 s in Fig. 5(a,b) shows that the diameters of exploded particles increase with increasing irradiation time at different distances (2.97 μm, 3.39 μm, 3.75 μm, 3.88 μm, 4.47 μm, 4.53 μm) from the center ball. The exploded Ga particles nearer to the center ball are bigger, and the increasing rate of the ball size decreases with increasing irradiation time. Figure 6(a) shows a randomly selected area of carbon film covered with Ga nanoparticles. The mean size of Ga nanoparticles is ~18 nm, and with a standard deviation of ~8 nm. At last, we studied the crystallization of Ga nanoparticles at low temperature. The Ga nanoparticles were successfully crystallized when cooling down to 90 K, and we can see clear lattice fringes in Fig. 6(b). Several 5–10 nm Ga nanoparticles don’t show evidence of crystallization (Fig. 6(c)), and they may still stay in liquid state at 90 K due to undercooling of liquid Ga nanoparticles31. The exploded particles have diameters in the range of 5–500 nm depending on the distances from the center ball. Thus, we can obtain Ga nanoparticles with different diameters through the explosion method.


Fabrication of nanoscale Ga balls via a Coulomb explosion of microscale silica-covered Ga balls by TEM electron-beam irradiation.

Chen Y, Huang Y, Liu N, Su J, Li L, Gao Y - Sci Rep (2015)

The relations of the diameter of the ejected Ga balls vs the distance from the center ball to the exploded particles, and the diameter of the Ga balls vs explosion time.(a) The diameters of the exploded particles decrease with increasing distance at the irradiation time of 1158 s; (b) The diameters increase with increasing irradiation time at different distances from the center ball.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477366&req=5

f5: The relations of the diameter of the ejected Ga balls vs the distance from the center ball to the exploded particles, and the diameter of the Ga balls vs explosion time.(a) The diameters of the exploded particles decrease with increasing distance at the irradiation time of 1158 s; (b) The diameters increase with increasing irradiation time at different distances from the center ball.
Mentions: It is found that the distribution of the exploded particles complies with a law during the explosion of microscale Ga balls covered by silica: the size of the exploded particles decreases almost linearly with increasing distance from the center ball, as demonstrated in a case at the moment of 1158 s in Fig. 5(a,b) shows that the diameters of exploded particles increase with increasing irradiation time at different distances (2.97 μm, 3.39 μm, 3.75 μm, 3.88 μm, 4.47 μm, 4.53 μm) from the center ball. The exploded Ga particles nearer to the center ball are bigger, and the increasing rate of the ball size decreases with increasing irradiation time. Figure 6(a) shows a randomly selected area of carbon film covered with Ga nanoparticles. The mean size of Ga nanoparticles is ~18 nm, and with a standard deviation of ~8 nm. At last, we studied the crystallization of Ga nanoparticles at low temperature. The Ga nanoparticles were successfully crystallized when cooling down to 90 K, and we can see clear lattice fringes in Fig. 6(b). Several 5–10 nm Ga nanoparticles don’t show evidence of crystallization (Fig. 6(c)), and they may still stay in liquid state at 90 K due to undercooling of liquid Ga nanoparticles31. The exploded particles have diameters in the range of 5–500 nm depending on the distances from the center ball. Thus, we can obtain Ga nanoparticles with different diameters through the explosion method.

Bottom Line: The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of carbon film.The ejected particles in the explosion increase their sizes with increasing irradiation time until the stop of the explosion, but decrease their sizes with increasing distance from the original ball.The Coulomb explosion suggests a novel method to fabricate nanoscale metal particles with low melting point.

View Article: PubMed Central - PubMed

Affiliation: Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074, P. R. China.

ABSTRACT
Nanoscale Ga particles down to 5 nm were fabricated by an explosion via an in situ electron-beam irradiation on microscale silica-covered Ga balls in a transmission electron microscope. The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of carbon film. The ejected particles in the explosion increase their sizes with increasing irradiation time until the stop of the explosion, but decrease their sizes with increasing distance from the original ball. The Coulomb explosion suggests a novel method to fabricate nanoscale metal particles with low melting point.

No MeSH data available.


Related in: MedlinePlus