【公開日：2025.06.10】【最終更新日：2025.05.16】
課題データ / Project Data
課題番号 / Project Issue Number
24UT0152
利用課題名 / Title
Effect of strain induced dislocations on structure and magnetization dynamics of rare earth garnet thin films
利用した実施機関 / Support Institute
東京大学 / Tokyo Univ.
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
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）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（副 / Sub）-
キーワード / Keywords
電子スピン共鳴装置、プローバーステーション,スピントロニクスデバイス/ Spintronics device
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)
AHAMED E M K IKBALL
所属名 / Affiliation
東京大学大学院工学系研究科電気系工学専攻
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
UT-305：環境制御マニュアルプローバステーション
UT-302：電子スピン共鳴装置
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
In rare-earth iron garnet (RIG) thin films, the coexistence of spin and dipole moments is expected due to spatial inversion symmetry breaking in nanoscale tilted strained structures. Dielectric polarization can be introduced in centrosymmetric garnets by strain engineering and forming a strain gradient layer which can be engineered through epitaxial strain control. This study aims to enable electric-field-controlled spin-wave propagation in symmetry-broken RIG thin films, offering a pathway for tunable magnetic devices
実験 / Experimental
We examined the magnetodynamics and spin dynamics of PLD-grown RIG thin films using electron spin resonance (JES-FA300). The angle-resolved ESR also determined the anisotropy. Also, the in-plane polarization characteristics were examined through a prober station(4200-SCS).
結果と考察 / Results and Discussion
The 80 nm-thick LuIG/SGGG film exhibits a polarization of less than 1 μC/cm², with a remanent polarization of approximately 0.65 μC/cm² under an applied electric field of 400 kV/cm. We determined the low Gilbert damping of the fabricated LuIG thin films as 10-3 level. We observed the reduction of centrosymmetry induced by tensile strain, which preserves a highly smooth surface and low Gilbert damping, unveiling new possibilities for studying controllable spin dynamics. These findings suggest that tensile-strained epitaxy can break inversion symmetry near the critical thickness, potentially enabling DMI-tunable spin dynamics in RIG thin films without the formation of misfit dislocations
図・表・数式 / Figures, Tables and Equations
Fig.1. ESR apparatus was used to investigate the magnetic properties of YIG/GGG/YAG thin films. The results are shown in Fig. 1. From the in-plane linewidth obtained from this data (2.3758 mT), it was confirmed that the damping constant of this thin film is on the order of 10-3, allowing for a quantitative understanding of its spin wave propagation potential.
Fig.2. Angle resolved out of plane ESR spectroscopy of Co-Si doped LuIG (LFCS) thin films
Fig. 3. (a) Optical image of the IDE fabricated on LuIG/SGGG thin films, (b) Polarization versus electric field loop of 20 and 80 nm-thick LuIG thin films grown on SGGG substrates along the in-plane direction. EMK Ikball Ahamed, ret. al., Adv. Electron. Mater. 2025, 2400735
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
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)
-
EMK Ikball Ahamed, Strain‐Induced Reduction of Centrosymmetry in Rare‐Earth Iron Garnet Thin Films, Advanced Electronic Materials, 11, (2025).
DOI: 10.1002/aelm.202400735
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- EMK Ikball Ahamed, et. al, “Dynamic control of spin-wave by electric field in rare-earth iron functional oxide thin films”, International Symposium on Quantum Electronics, Feb 13-16, 2024,The University of Tokyo, Japan
- EMK Ikball Ahamed, et.al “Electric field controlled dynamic modulation of spin wave in rare earth iron functional oxide thin films,” The 71st JSAP Spring Meeting, March 2024
- EMK Ikball Ahamed, et. al, “Dynamic control of spin wave propagation by electric field in space inversion symmetry broken Iron Oxide Garnet thin films,” 85th JSAP Autumn Meeting, September 2024
- EMK Ikball Ahamed, et. al, “Electrical control of magnon propagation in Iron Oxide Garnet thin films,” 30th International Workshop on Oxide Electronics (IWOE 30), September 2024, Darmstadt, Germany
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