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

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.

通过在透射电子显微镜中对微米级二氧化硅包覆的镓球进行原位电子束辐照爆炸，制备出了小至5纳米的纳米级镓颗粒。由于爆炸发生在绝缘的二氧化硅包覆的镓微球的表面而非整个球体，以及碳膜边缘的纯镓纳米球上，所以可以确定这种爆炸是库仑爆炸。爆炸中喷射出的颗粒在爆炸停止前随着辐照时间的增加而尺寸增大，但随着与原始球距离的增加而尺寸减小。库仑爆炸为制备低熔点的纳米级金属颗粒提供了一种新方法。