A quasicrystalline transition state in an annealed Al₆₅Cu₂₀Fe₁₅ alloy

A quasicrystalline transition state was found in an Al₆₅Cu₂₀Fe₁₅ alloy after heat treatment at 700 °C and subsequent slow cooling of samples originally containing the icosahedral quasicrystalline phase. The transition state is characterized by the simultaneous presence of two types of quasicrystalline domains. Their structure can be obtained by the introduction of one-dimensional periodicity along one of the fivefold axes of the original icosahedral quasicrystal. The two types of domains differ in their period lengths which are obtained by multiplying a fundamental length of the icosahedral structure by the Fibonacci numbers 5 and 8.