SYNTHESIS OF NANOSIZE POWDERS OF ALUMINA BY ABLATION PLASMA PRODUCED BY INTENSE PULSED LIGHT-ION BEAM

Nanosize powders of alumina have been synthesized by high-density abla tion plasma produced by the irradiation of an intense, pulsed, light-i on beam on an aluminum target in oxygen. Diameters of the powders, whi ch are observed to be spherical, are typically 5-25 nm. At 1 Torr of o xygen, nanosize powders of aluminum are synthesized with those of a sm all amount of gamma-alumina. At 10 Torr of oxygen, on the other hand, gamma-alumina powders are produced with a small amount of aluminum pow ders. Annealing characteristics in nitrogen have also been studied on the transition from gamma- to alpha-alumina. (C) 1995 American Institu te of Physics.