Stacking of hexagonal layers in the structure of β-Mg₂Al₃

Abstract

An analysis of cross-sections perpendicular to the main diagonal of a cubic elementary cell of a Samson structure–β-Mg₂Al₃ has been conducted. It has been proved that all skeleton atoms, i.e. which occupy their positions with probability of 100%, form a framework of hexagonal planes. These planes are a part of three domains shifted with respect to each other by one-third of the length of cube's diagonal. Space between domains is filled up by clusters with partially occupied atomic positions. For hexagonal domains, the elementary cell and positions of decorating atoms have been determined.

Keywords:

• Mg₂Al₃
• Samson phase
• domain structure
• magnesium alloys
• X-ray diffraction

Acknowledgement

This work has been partially supported by CMA-NoE.