2019 Fiscal Year Final Research Report
Controlling spatial distribution of rare-earth elements in III-nitride semiconductors and their magnetic properties
Project/Area Number |
17H02775
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Crystal engineering
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Research Institution | Osaka University |
Principal Investigator |
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Co-Investigator(Kenkyū-buntansha) |
薮内 敦 京都大学, 複合原子力科学研究所, 助教 (90551367)
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Project Period (FY) |
2017-04-01 – 2020-03-31
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Keywords | エピタキシャル成長 / 窒化物半導体 / 空間分布制御 / 結晶構造 / 磁気特性 / 陽電子消滅法 / 原子空孔 / 第一原理計算 |
Outline of Final Research Achievements |
We have focused on controlling and analyzing the spatial distribution of rare-earth (RE) elements in III-nitride semiconductors toward growth of nitride-based magnetic semiconductors in a reproducible fashion. The three types of samples with the different spatial distributions of RE elements (random, 2-dimesional (2D), and 3-dimesional (3D) types) were grown by plasma-assisted molecular beam epitaxy: conventional RE-doped GaN films, superlattices (SLs) consisting of sub-nm-thick RE nitride (REN) layers and ~5-nm-thick GaN layers, and SLs consisting of sub-nm-thick REN and ~2-nm-thick GaN layers, respectively. Structural analyses showed that the growth of GaN/REN SLs is a suitable method for controlling the spatial distribution of RE elements in GaN. Magnetic and magneto-optic properties for the three types provide an experimental evidence that controlling spatial distribution of RE ions in GaN is crucial for improving its magnetic properties.
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Free Research Field |
分子線エピタキシー法による半導体材料創製とその物性評価
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Academic Significance and Societal Importance of the Research Achievements |
磁性半導体は,次世代高度情報化社会の基盤を支える光電子デバイス材料の有力な候補と目されている.その材料創製実現に向けて,磁性元素添加方式による改善,すなわち磁性元素の空間分布制御による磁気特性向上が可能であることを示す研究成果が得られている.磁気特性と磁性元素の空間分布の相関に関する知見は,窒化物磁性半導体での磁性発現機構解明に貢献する成果である.また,本研究で提案した添加方法によりナノ領域での結晶構造制御が可能となることを示しており,新たな材料創製への道を拓く成果と言える.
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