Mg_20.66Al_12.24Zn_20.04

Area of Science:

• Materials Science
• Crystallography
• Solid-state Chemistry

Background:

• Magnesium-aluminum-zinc (Mg-Al-Zn) alloys are important in various industrial applications.
• Understanding the high-pressure synthesis and crystal structure of these alloys is crucial for material design.
• Previous structural models for related compounds may not fully capture complex phase formations.

Purpose of the Study:

• To characterize a novel single-crystal phase in the Mg-Al-Zn system synthesized under extreme conditions.
• To determine the precise crystallographic structure, including space group and atomic site occupancies.
• To compare the obtained structural model with existing literature data.

Main Methods:

• High-pressure and high-temperature synthesis of Mg-Al-Zn alloy.
• Single-crystal X-ray diffraction for structural determination.
• Analysis of crystallographic data to identify space group and atomic positions.

Main Results:

• A single crystal of an icosa-magnesium dodeca-aluminum icosa-zinc phase was successfully synthesized.
• The crystal structure was determined to be in space group Im3 (No. 204).
• Seven distinct metal-atom sites were identified, with specific Al, Zn, and Mg occupancies, including one Al/Zn site with icosahedral coordination.

Conclusions:

• The synthesized Mg-Al-Zn single crystal represents a new structural phase.
• The determined crystal structure exhibits significant differences compared to previously reported models.
• This finding necessitates a revision of structural understanding for Mg-Al-Zn alloys under high-pressure conditions.