Preparation of quasicrystalline thin films and fine particles by gas evaporation

Quasicrystalline fine particles were prepared by gas evaporation using a tungsten heater as well as a pulsed laser. Particles obtained were spherical, and their average size increased with increasing gas pressure. When particles were produced by pulsed laser, their size was more uniform than those produced by use of a tungsten heater because fast expansion of vapor from a source leads to negligible convection. Utilization of the fine particles was also demonstrated. For example, fine particles were accelerated by gas flow and sprayed on a substrate. A film with metallic luster was formed at room temperature. This suggests that a dense film is obtained by the method. This technique will enable us to prepare quasicrystalline films with fine grain size at low temperature.