STRUCTURAL STUDY OF THE Al-Mn-Pd HIGH-ORDER APPROXIMANTS

摘要

Structural models of the AI-Mn-Pd high-order approximants are proposed. It is considered that the approximants and the Al-Mn-Pd decagonal quasicrystal are composed of the same kinds of subunits, periodic packings (in different ways) in the former and aperiodic packing in the latter. The subunits are derived from the structure of the Al3Mn phase and they are consistent to the high-resolution electron microscopy image of the Al-Mn-Pd decagonal quasicrystal. As an example, the structural model of the Al-Mn-Pd (2/1,5/3) high-order approximants is discussed in detail.