Stable decagonal quasicrystals in the Al-Fe-Cr and Al-Fe-Mn alloy systems

Stable decagonal quasicrystals were revealed for the first time in the Al-Fe-Cr and Al-Fe-Mn alloy systems. They exhibit periodicity of ∼1.2 nm along the 10-fold symmetry axis and are formed around the Al72Fe12Cr16 and Al72Fe10Mn18 compositions, respectively. In Al-Fe-Cr the decagonal phase was only produced after prolonged thermal annealing at subsolidus temperatures (maximum 1090 °C). In Al-Fe-Mn a strong temperature dependence of the compositional region of the decagonal phase was observed.