A search for quasiperiodic cubic crystals in Mg-Al alloys

2015 Fiscal Year Final Research Report

• Project/Area Number: 26630290
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: The University of Tokyo
• Principal Investigator: Abe Eiji 東京大学, 工学(系)研究科(研究院), 准教授 (70354222)
• Research Collaborator: KATO Takeshi ; SEKI Takehito
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 準結晶 / 電子顕微鏡 / 結晶学 / 原子配列 / マグネシウム合金 / 複雑合金相

Outline of Final Research Achievements

Quasicrystals are constructed by quasiperiodic arrays of atoms, and their physical origin has been attributed to the unique rotational symmetry (e.g., five-fold rotational symmetry) that is incompatible with conventional periodic order. In the present study, we show that, for the first time, the quasiperiodic atomic structure occurs with a normal cubic symmetry (i.e., quasiperiodic cubic crystal) in a rapidly solidified Mg-60at%Al alloy, based on hyperspace crystallography analysis of the electron diffraction patterns and the direct structure observations by high-resolution electron microscopy. The present observations suggest that the quasiperiodic order is governed not by underlying specific symmetry but perhaps by intrinsic interactions between the atoms/molecules, providing an important hint on the hierarchical principle how the atoms build up periodic/aperiodic materials.

Free Research Field

材料科学