Contrast Variation Effects on Neutron Diffraction Patterns with Quasi-Periodic Structures

Aluminium-based icosahedral phases (ABIP) have been investigated by neutron diffraction. Isomorphous substitution of manganese (a negative neutron scatterer) by Fe or FeCr (positive neutron scatterers) have allowed production of contrast variations for the determination of the partial structure factors. Evidences for centrosymmetry have been obtained.