The Preparation And Electron Microscope Irradiation Researches On Gallium Particle Covered By Silica

Microscale, submicron and nano materials exhibit chemical, good catalyticperformance because they have many surface-atoms with many dangling bonds andunsaturated bond properties. Low melting point metal can reduce the target substanceformation temperature greatly and energy consumption. We prepared microscale~submicron silica cover Ga particles by CVD in vertical frequency induction furnace, andnano scale metal Ga catalyst by electron beam irradiation in TEM. The main results arefollowing:(1) Get micro, submicron/nano scale gallium particles covered by silicain in verticalinduction furnace by CVD, explain the growth mechanism.(2) Various nanoscale Ga catalyst were fabricated via TEM electron-beam irradiationon microscale silica covered gallium balls. The results are the following: silica cover Gaparticles and the pure Ga particles on the edge of C film will explode under electron beamirradiation, the diameter of the original ball is decreasing with the increasing of irradiationtime, and the rate of the decreasing is diminishing; there are many new small pure Gaparticles distribute around the original ball, their diameter is increasing until the explosionstop, the rate of increasing is decreasing, the farther from the original ball the smaller ofthe new Ga particle, and the smallest is about5nm. These results support that thisexplosion is a kind of Coulomb explosions.(3) Analyze the factors about explosion on silica cover Ga ball under electron beamirradiation by a spherical core-shell structure model. the primary facts are the pressurecaused by electron beam irradiation, theory combining strength of Ga and silica, and thesurface tension of the Ga.