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First Direct Synthesis of Graphene/Half-metallic Heusler Alloy Heterostructure for Spintronic Device Applications
https://repo.qst.go.jp/records/72730
https://repo.qst.go.jp/records/727307ee0e314-522c-4217-a15d-b419de0f3f49
Item type | 会議発表用資料 / Presentation(1) | |||||
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公開日 | 2018-02-20 | |||||
タイトル | ||||||
タイトル | First Direct Synthesis of Graphene/Half-metallic Heusler Alloy Heterostructure for Spintronic Device Applications | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
資源タイプ | conference object | |||||
アクセス権 | ||||||
アクセス権 | metadata only access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
著者 |
李, 松田
× 李, 松田× 境, 誠司× 圓谷, 志郎× Naramoto, Hiroshi× 渡邉, 貴弘× 桜庭裕弥× 雨宮, 健太× B. Sorokin, Pavel× Songtian, Li× Sakai, Seiji× Entani, Shiro× Naramoto, Hiroshi |
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抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | The low spin signal and tiny magneto-resistance is becoming a central issue in graphene-spintronic devices [1] in which conventional ferromagnets (FMs) such as Ni, Co, Fe of low spin polarization were used. Adopting highly spin-polarized material such as half-metal into graphene/FM heterostructure can be the most effective way to enhance the performance of graphene-spintronics device, experimental demonstration, however, is still lacking. This study, for the first time, reports a new heterostructure consisting of a single layer graphene (SLG) synthesized by high-vacuum chemical vapor deposition (CVD) on Co2FeGe0.5Ga0.5 (CFGG) Heusler alloy whose half-metallicity has been confirmed experimentally [2]. CFGG layer with a thickness of 50 nm was epitaxially grown on a MgO(001) single-crystal substrate by magnetron sputtering at room temperature. The CFGG/MgO sample was then transferred into a CVD chamber for graphene synthesis. SLG was successfully synthesized on CFGG by optimizing the CVD process. Fig. 1 shows the STM image taken from the synthesized SLG/CFGG heterostructure, which reveals an epitaxial growth of SLG on CFGG. Due the large lattice-mismatch between CFGG and graphene, moiré pattern of graphene is observed. Fig. 2 shows the C K-edge XAS spectra of the SLG/CFGG heterostructure obtained by changing the incidence angle of a linearly polarized x-ray beam. The peak intensity from the π* and σ* state of graphene shows an opposite behavior of incidence-angle dependence, convincing the formation of a graphitic structure. Strikingly, the peak from the π* state of grapene observed here is very sharp, indicating a weak chemical bonding between graphene and CFGG. It makes the SLG/CFGG heterostructure unique from other graphene/FM systems such as SLG/Ni, Co, Fe which have received intensive studies so far. The quasi-freestanding nature of graphene on CFGG makes the SLG/CFGG heterostructure extremely promising for high-performance spintronic devices. [1] Han et al. Nat. Nanotechnol. 9, 794-807 (2014); [2] Li et al. Appl. Phys. Lett. 103, 042405 (2013). |
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会議概要(会議名, 開催地, 会期, 主催者等) | ||||||
内容記述タイプ | Other | |||||
内容記述 | 第65回応用物理学会春季講演会 | |||||
発表年月日 | ||||||
日付 | 2018-03-17 | |||||
日付タイプ | Issued |