Formation of Ultrafine Metal Particles by Gas-Evaporation VI. Bcc Metals, Fe, V, Nb, Ta, Cr, Mo and W

Authors:
  • YSYahachi Saito
    Yahachi Saito
  • KMKazuhiro Mihama
    Kazuhiro Mihama
  • RURyozi Uyeda
    Ryozi Uyeda

Abstract
The crystal structures and habits of bcc metal particles have been investigated systematically by electron microscopy. The habits for the bcc structure are rhombic dodecahedra truncated by six {100} faces with various degrees of truncation from 0 to 100%. The truncation degree for Fe and V particles grown in the intermediate zone of a metal smoke is in good agreement with that for the Wulff polyhedron expected from the surface energies calculated for {110} and {100} faces. Particles of Cr, Mo and W have the A-15 type structure besides the ordinary bcc structure. The present results support the hypothesis that the A-15 type structure is stable when the particle size is small. The habits for the A-15 type structure are rhombic dodecahedra (Cr), {211} icositetrahedra (Cr and Mo) and rounded cubes (Mo and W).

This publication has 22 references indexed in Scilit: