Al-Mn quasicrystal ultrafine particles can be produced by the advanced gas evaporation method (AGEM), which is a method of preparing ultrafine alloy particles by coalescence growth among the particles near the evaporation sources. We investigated the phase transition temperature from a quasicrystal to a stable crystal, by examining successive electron diffraction patterns of an ultrafine particle in an in situ experiment using a transmission electron microscope. In spite of the report that the Al86Mn14 quasicrystal transforms into the crystal phase at around 400-670 °C on thin film specimens, the quasicrystal ultrafine particle transformed at 800 °C, i.e., the quasicrystal ultrafine particle is more stable. Since the cross-sectional view of the surface oxide layer of the quasicrystal ultrafine particles can be easily observed, the surface oxides of n-Al2O 3 and MnO were characterized as a result of the oxidation of residual atoms on the surface of the produced alloy particles including the quasicrystals. The conditions required for Al-Mn quasicrystal ultrafine particle formation by the AGEM can be estimated under the cooling rate of 105K/s.
|ジャーナル||Physica E: Low-Dimensional Systems and Nanostructures|
|出版ステータス||Published - 2005 1 1|
ASJC Scopus subject areas