Special planar defects in the structural complex metallic alloys of Al–Pd–Mn and Al–Ni–Rh

Abstract

Abstract A systematic high-resolution electron microscopy study of a special type of two-dimensional defects, phason planes, has been carried out in the structurally complex metallic alloys of Al –Pd –Mn and Al –Ni –Rh. The structural characteristics of the phason planes in these two alloys consist of pentagon-banana pairs of polygons but with a different arrangement. Located on the vertex of the polygons are pseudo-Mackay atomic clusters. The detailed atomic structures of the phason planes in both ξ′- and ξ-phases of the two alloys have been determined by means of high-resolution electron microscopy and theoretical simulations. The possible ways of displacement of the phason planes in the complex alloys are discussed.