【公開日：2024.07.25】【最終更新日：2024.06.14】
課題データ / Project Data
課題番号 / Project Issue Number
23UT0151
利用課題名 / Title
Development of icosahedral quasicrystal with long-range magnetic order
利用した実施機関 / Support Institute
東京大学
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed
キーワード / Keywords
金属間化合物/ Intermetallic compounds, 軟磁性材料/ Soft magnetic materials,電子顕微鏡/ Electronic microscope
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Labib Farid
所属名 / Affiliation
東京理科大学 先進工学部 マテリアル創成工学科
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
The purpose of this project is to develop new types of icosahedral quasicrystals (iQCs) and their cubic approximant crystals (ACs) with long-range magnetic orders. In this work, we synthesized iQCs and ACs in various alloy systems and chemical compositions and characterized their atomic structures and symmetries using JEM-2010F TEM. The results confirmed the successful synthesis of iQCs and ACs with icosahedral and cubic symmetries, respectively. In the case of iQCs, the clearτscaling feature is observed in the pattern indicating their primitive type identical to the prototype Cd5.7Yb iQC. In the case of ACs, the presence of "linear phason strain" in their structure is confirmed. All the samples exhibit ferromagnetic long-range order.
実験 / Experimental
In this research, Au-based iQCs and ACs were successfully synthesized. Their selected area electron diffraction (SAED) patterns are investigated at room temperature using TEM, JEM-2010F at Advanced Research Infrustructure for Materials and Nanotechnology. For the experiment, the samples were crushed in ethanol and transferred to a Cu grid. After confirming their symmetries and structure via TEM, the samples were further analyzed by Superconducting quantum interference device (SQUID) magnetometer for their magnetic properties investigation.
結果と考察 / Results and Discussion
In this project, we discovered new types of Au-based iQCs and ACs with long-range ferromagnetic orders. In the case of iQCs, an icosahedron symmetry with a clearτscaling feature is observed in the SAED patterns (see Fig. 1) indicating their primitive type being identical to the prototype Cd5.7Yb iQC. This sample is the first pure ferromagnetic iQC discovered to date (see magnetic susceptibility in Fig. 2).
We also discovered new types of 1/1 and 2/1 ACs with long-range ferromagnetic orders. In their SAED patterns, we confirmed cubic symmetries with space groups Im-3 and Pa-3, respectively. We also observed clear zig-zag arrangement of the diffraction spots (see Fig. 3). In principle, ACs can be viewed as QCs with “linear phason strain”, the magnitude of which can be gauged from disposition of the strong reflections from ideal positions observed in strain-free iQC. The Zig-zag configuration of the reflections (being less visible in the 2/1 AC) is direct evidence of “linear phason strain” in ACs. Both these samples are ferromagnetically ordered (see Fig. 4).
図・表・数式 / Figures, Tables and Equations
Fig. 1) Selected-area electron diffraction (SAED) pattern of the ferromagnetic Au65Ga20Dy15 iQC along the fivefold axis.
FIG. 3. SAED patterns obtained from (a,c) 1/1 AC and (b,d) 2/1 AC along incident axes perpendicular to (a,b) [110] and (c,d) [111] directions. Zig-zag configuration of the reflections in Figs. 2c and 2d reflects structural deviation of the ACs from a perfect aperiodic atomic arrangement in iQC and is denoted as “linear phason strain” in their structure.
FIG. 2. Temperature dependence FC magnetic susceptibility (M/H) of the AuxGa85-xDy15 (x = 62, 65, and 68) i QCs. The inset shows Cp/T variation in the same samples as a function of temperature T in the range of 0–25 K.
FIG. 4. Low temperature magnetic susceptibility M/H of the 1/1 AC (represented by red) and 2/1 AC (represented by blue) under field-cooled (FC) and zero-field-cooled (ZFC) modes. The inset shows field dependence magnetizations at 1.8 K up to Hdc = 7 T.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
口頭発表 １．Farid Labib et al. Single ferromagnetic and successive ferromagnetic/antiferromagnetic transitions in Au-Ga-Tb 1/1 approximant crystals, 2023 Spring Meeting of the Physical Society of Japan (online) 2023 March, 23rd.２．Farid Labib et al. Magnetic properties of the Dy-contained 1/1 approximant crystals, The Japan Institute of Metals and Materials (JIM) 2023 Spring Meeting, Tokyo, Japan, 2023 March 8３．Farid Labib et al. Comparative study of ferromagnetic long-range order in Tsai-type 1/1 and 2/1 approximant crystals, 27th Quasicrystals meeting, Nagoya, Japan, 2023 Feb. 28
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- 10.48550/arXiv.2310.14292
- Farid Labib et al. Magnetocaloric effect in Ga-based quasicrystal approximants, 2023 autumn Meeting of the Physical Society of Japan (onsite) 2023 September, 16th.
- Farid Labib et al. Magnetic properties investigation of the Au-Ga-Tb 1/1 approximant crystals with single ferromagnetic and successive ferromagnetic/antiferromagnetic transitions, 26th congress and general assembly of the international union of crystallography (on site) 2023 August, 24th.
- 10.1103/PhysRevLett.130.176701
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件