One-dimensionally modulated quasicrystal phase related to icosahedral Al-Mn-Pd

A new one-dimensionally modulated quasicrystal phase related to the icosahedral Al-Mn-Pd quasicrystal is described from an alloy with composition o Al Mn Pd annealed at temperatures between 550 and 715 C and 69.8 8.3 21.9 subsequently quenched in water. Systematic tilting experiments reveal that this phase is an icosahedral quasicrystal with a modulation along one of its threefold symmetry axes. It therefore has a trigonal-symmetric Fourier spectrum and a modulation period along the unique threefold axis which corresponds to 15.7 nm. This long-rangeordered phaseis relatedtotheusualF-type icosahedralquasicrystal as well as to the F2 icosahedral quasicrystal which has a P-type icosahedral lattice.