The icosahedral quasicrystal phase has been produced by precipitation from the solid phase during ion implantation of Mn into oriented films of fcc Al on NaCl. Implantations at substrate temperatures of 20 °C, 150 °C, and 275 °C resulted in amorphous, icosahedral, and crystalline phases, respectively. Microdiffraction patterns were obtained from individual icosahedral grains which had precipitated within the bulk of the Al grains. They are oriented with three mutually perpendicular twofold axes of the icosahedral structure parallel to the [001], [110], and [11¯0] directions of the fcc Al matrix.

• Received 16 October 1985

DOI:https://doi.org/10.1103/PhysRevB.33.2876