Preparation Of Spherical Nano-Cerium Dioxide By Detonation

Cerium Dioxide nanopaticles were one kind of important abrasive materials for chemical-mechanical planarization. Spherical nano-cerium dioxide powders could reduce polishing defects because of their spherical shape without facetings. Therefore, for cerium oxide usesd as abrasive, the spherical and glazed cerium oxide particles were more useful than the cerium oxide powders with facetings.In this paper, spherical nano-cerium oxide particles were prepared by detonation method, in which the explosives were mixed with cerium nitrate and other additives such as urea.The detonation products were characterized by XRD(X-ray Diffraction) and TEM(Transmission Electron Microscope).The results indicated that the obtained cerium oxide crystals were cubic fluorite structure. The particles had spherical shape and their granule dimensions were smaller than 100nm.The influence of dispersant on the morphology of detonation products was also investigated. The cerium oxide crystals presented spherical shape with the explosive(hexogen) mixed urea. The particles had the smallest granule dimensions and better dispersity with sodium nitrite and urea coexisted in the explosive. With sodium chloride and urea coexisted in the explosive, particles obtained congregated seriously. The offset of cerium oxide diffraction peaks was analyzed with the Prague equation. This right-offset of cerium oxide diffraction peaks was caused by the decrease of the face distance of cerium oxide crystals. Through comparison of particle size,dispersity and particle appearance, the sodium nitrite and urea were regared as the best additive for preparing spherical cerium oxide.The explosion heat and explosion temperature of the explosives were calculated. The density and the explosion velocity of the explosives were mensurated. This data might be taked as the reference of granule dimension growing and other researches invoving in synthesis via detionation.The spherical nano-cerium oxide particles prepared by the detonation method had uniform grain size and good dispersity. This method had advantages of fast synthesis, simple technology process and low-cost equipment.