ATOMIC-STRUCTURE OF THE AL-PD-MN ICOSAHEDRAL PHASE

Perfect single grains of the Al-Pd-Mn icosahedral phase have been used for atomic structure determination by X-ray and neutron diffraction. Due to the large difference between X-ray and neutron scattering factors, the atomic position of the three elements of the alloy can be precisely determined. In the 6D description, the lattice is face centered but can be viewed as a superstructure from the primitive lattice due to a strong chemical ordering. All the palladiums are on the even nodes of the 6-dimensional cube, and odd body centres.