Quasicrystalline and related crystalline phases in Al-Pd-Fe system

Abstract

X-ray and electron diffractions of melt-quenched Al-Pd-Fe alloys reveal that a face-centered icosahedral and a decagonal phase with a periodicity of 1.6 nm(D1.6) can exist over a range of compositions varying from 15 to 20 at% Pd, 10 to 15 at% Fe and from 10 to 25 at% Pd, 0 to 15 at% Fe, respectively. The D1.6 and an one-dimensional (1D) quasicrystal were, respectively, found to be formed in annealed Al75Pd15Fe10 in different annealing conditions. A stable 1/2 type cubic approximant of i-phase was found in the composition close to Al70Pd10Fe20. A complex structure consisting of the regions of monoclinic crystalline, D1.6 and modulated lattice has been observed in a fully annealed Al75Pd10Fe15 which was presumedly an intermediate toward to crystalline phases.