Determination Overlapping Interface Structure in the ξ´-Al-Ni-Rh Approximant Phase

Abstract

The structure of the overlapping interface in ξ´-Al-Ni-Rh was determined by calculating the total energy of super lattices containing defect structures using the modified analytic embedded-atom method (MAEAM). The structure analyses indicated that only two equivalent types of interfaces exist, which are defined as the PF and PI types. Calculation of the PF- and PI-type super cells indicated that the interface between the close-packed P layer and the slightly puckered I layer has a lower energy and may be a static interface. Although the PI-type overlapping interface may seriously corrupt decagonal cluster columns in the approximant phase, it causes relatively less corruption of the metallic bonds than the PF mode. The total energies of the three types of super lattices caused by different displacement vectors between the two domains found in ξ´-Al-Ni-Rh were also calculated. The domain boundary translated with a vector of r =a + c is the most static state among the three type super lattices from energy perspective.