Some new stable one-dimensional quasicrystals in an Al65Cu20Fe10Mn5 alloy

Abstract

Structure types and fine structures of the stable one-dimensional (1D) quasicrystals (QCs) in an Al65Cu20Fe10Mn5 alloy have been studied using transmission electron microscopy. The 1D QCs are intimately related to a prototype decagonal quasicrystal (DQC) and may be described by introducing appropriate linear phason strains into the DQC. In the present work we have observed three types of 1D QC with lattice parameters of a1=8 0.23nm=1.84 nm,c= 1.2 nm,a2=18 0.23 nm = 4.14 nm,c2=1.2 nm and a3=13 0.23 nm = 2.99nm,c3= 1.2 nm respectively, where c1=c2=c3 is the period along the original tenfold axis (A10) of the prototype DQC and a1, a2 are the periods along one of the A2P axes of the prototype DQC with different 3 linear phason strains. The multiplicative values before 0 .23 nm for a1 and a3 belong to the numbers of one type of Fibonacci sequence with N=1 and N1=3, while that for a2 belongs to a number of another type of Fibonacci sequence with N0=1 and N= 3. The latter two 1D QCs are discovered for0 1 the first time. Chalk-like needle domains along the A10 direction and wavy thin plate domains perpendicular to the A10 direction have been observed in some regions of the 1D QC.