Fine particles of icosahedral quasicrystal formed by gas evaporation technique

Al-T (T=Mn, V, Cr) particles in the icosahedral phase have been prepared by evaporation and condensation of metals in an inactive gas. The particles were spherical in shape, with diameters ranging from 50 to 300 nm, and showed speckled contrast in bright and dark field images. Each particle consisted of fine grains of several nm with small misorientations (less than a few degrees). Patterson functions of the icosahedral Al-Mn were also calculated from electron diffraction data. Among several structure models examined in the present study, a model with an array of two-shell Mackay icosahedra gave the best fit with the Patterson functions.