A study of the icosahedral phase: Mg32 (Al, Zn)49

Abstract
Homogeneous single phase Mg32Al19Zn30 was melt spun to form flakes suitable for TEM examination. The nodular structure gave diffraction patterns with 5.3.2 icosahedral point group symmetry. The formation of the icosahedral phase is rationalized in terms of the Mg(AlZn)49 equilibrium structure. This structure is a Frank-Kasper phase. It has previously been established how such icosahedral order can be anticipated in the Frank-Kasper phases.