Study on the Ordered Phases with Long Period in the Gold-Zinc Alloy System II. Structure Analysis of Au₃Zn[R₁], Au₃Zn[R₂] and Au₃₊Zn

Abstract

Crystal structures of the ordered phases, Au₃Zn[R₁], Au₃Zn[R₂] and Au₃₊Zn are investigated by X-ray diffraction using single crystals. The structure models proposed by Wilkens and Schubert for Au₃Zn[R₂] and Au₃₊Zn are confirmed substantially, but partly corrected. The structure analysis of a new phase Au₃Zn[R₁] is given, and the stacking faults present in this phase is investigated. It is suggested that the complicated atom shifts similar to those in Au₃Zn[R₁] and Au₃Zn[R₂] take place also in Au₃₊Zn.
It is proposed that such complicated atom shifts seem to be a phenomenon not peculiar to the ordered phases in the Au-Zn alloy system but common to the ordered phases with long periods, such as Au₃Cd, Ag₃Mg, Cu₃Pd, CuAu II.