Formation and structure analysis for F-type superstructure of Cd-Mg-Yb icosahedral quasicrystal

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K13987
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Tokyo University of Science
• Principal Investigator: Tsunetomo Yamada 東京理科大学, 理学部第一部応用物理学科, 助教 (60638584)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 準結晶 / 高次元結晶学

Outline of Final Research Achievements

The following results were obtained regarding the short-range order of superstructure of the Cd-Mg-Yb icosahedral quasicrystal. 1. As a result of the structure analysis of F-type superstructure of the Cd-Mg-Yb 1/1 approximant, the formation of the F-type superstructure order is resulted from the selective occupation of Cd/Mg at 48 h site on the icosidodecahedron shell and the orientation of innermost tetrahedron shell. 2. A six-dimensional structural model of the primitive Tsai-type icosahedral quasicrystals was modified so as to incorporate the selective Cd/Mg occupation found in the 1/1 approximants. 3. A Python3 package for structure modelling of icosahedral QCs was developed.

Free Research Field

金属材料

Academic Significance and Societal Importance of the Research Achievements

単結晶回折法による準結晶の構造解析手法は確立されたものであり、構造精密化等のためのソフトウェアパッケージが公開されている。ただし、高次元構造を作成するためのソフトウェアが無く、構造モデルの作成・改良には膨大な時間と労力を必要としてきた。本研究により、正二十面体準結晶の6次元構造を構築するためのソフトウェアが開発・公開されたことに学術的意義がある。