SYNTHESIS OF TIO2 AND TIN NANOSIZE POWDERS BY INTENSE LIGHT ION-BEAM EVAPORATION

Ultrafine nanosized powders of TiO2 and TiN have been synthesized by t he reactive ion-beam evaporation technique. In an oxygen or nitrogen a tmosphere (1-10 Torr), a high-power-density ion beam (about 0.4 GWcm(- 2)) is focused onto a Ti target; as a result of the interaction betwee n ablated particles and gas, fine and ultrafine powders are synthesize d. The influence of gas pressure and target-collector distance on the particle composition, size distribution and shape have been studied. A t longer target-collector distances and higher pressures, powders in t he 4-45 nm range are collected while, at shorter distances and lower p ressures, the powders are in the micrometre range. TiO2 particles are spherical in shape, while TiN particles are cubic.