Ultrafine particles and production method thereof

摘要

An electron beam of more than 1 x 10<19> e/cm<2>.sec is irradiated upon metastable metal oxide particles such as THETA -Al2O3 particles 1 disposed on an amorphous carbon film. A phase transformation of the metastable metal oxide particles results from the electron beam irradiation. Thus, stable metal oxide ultrafine particles such as alpha -Al2O3 ultrafine particles 2 whose diameter is smaller than the metastable metal oxide particles used, can be produced. Metal nanoparticles of a metal component of the oxide such as of aluminium may also be produced. <IMAGE>