Chemical-twinning mode of the B2 structure in relation to Al-Cu approximants

Author: Dong Chuang   Zhang Qiuhua   Wang Dehe   Wang Yingmin  

Publisher: Taylor & Francis Ltd

ISSN: 0141-8610

Source: Philosophical Magazine. A. Physics of Condensed Matter. Defects and Mechanical Properties, Vol.79, Iss.3, 1999-03, pp. : 501-510

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Complex structures can be regarded as being derived from a few basic structures via the local twinning at the atomic level. Although quasicrystals and approximants are believed to be the B2 derivatives, the related B2 twinning mode is not known. This paper addresses this problem by analysing the twinning property of Al-Cu approximants in an Al3Cu4 sample. Such an analysis leads to the recognition of the B2 chemical-twinning mode as 180o/<111>B2, which is responsible for the pentagonal atomic configuration in the Al-Cu approximants as well as for the pseudofivefold B2 twinning observed on quasicrystal surfaces.