Design of Spin Transport Properties in Fullerene-Transition Metal Hybrid Materials

富勒烯-过渡金属杂化材料自旋输运性能的设计

• 批准号: 19360290
• 负责人: SAKAI Seiji
• 金额: $ 10.73万
• 依托单位: Japan Atomic Energy Agency
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2007
• 资助国家: 日本
• 起止时间: 2007 至 2009
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-19360290/
• 关键词: ナノ物性; フラーレン; 遷移金属; ナノ粒子; 磁気抵抗; スピントロニクス; 有機分子; スピン偏極; 分子スピントロニクス; 界面; 磁気抵抗効果; トンネル磁気抵抗効果; トンネル効果; スピン注入; フフーレン

Systematic studies were conducted on the giant TMR effect found in the fullerene(C_<60>)-cobalt(Co) granular thin films, which are composed of a C_<60>-Co compound matrix and Co nanoparticles precipitated therein. It was revealed that the C_<60>-Co films show TMR ratios as high as several 100%-1000% reflecting the dispersion state of Co nanoparticles which can be control by the sample composition. Synchrotron X-ray absorption and magnetic circular dichroism studies clarified that there exist localized d-spins in the C_<60>-Co compound matrix, and the localized spins have a predominant effect on the temperature dependence of the TMR magnitude. It was clarified from the analysis of the electrical and TMR properties of the devices with a nano-layered structure that the giant TMR effect at low temperatures is due to higher-order cotunnleing process, which is related to the granular structure of the films, and, more importantly, due to nearly-complete spin polarization (higher than 80% at zero temperature and bias) of tunneling electrons generated at the interface of Co nanoparticle and the C_<60>-Co compound. The nearly-complete spin polarization of tunneling electron is indicated to be a characteristic nature of the present hybrid system realized under the condition of well defined granular structure and independent of device structure.

对富勒烯（C_ <60>） - 钴（CO）颗粒状薄膜中发现的巨型TMR效应进行了系统研究，该薄膜由C_ <60> -Co -Co化合物基质和CO纳米颗粒组成。据显示，C_ <60> -Co膜显示的TMR比率高达几个100％-1000％，反映了可以通过样品组成控制的CO纳米颗粒的分散状态。同步加速器X射线吸收和磁性圆形二色性研究澄清说，C_ <60> -CO化合物基质中存在局部d-spin，而局部旋转对TMR幅度的温度依赖性具有主要作用。 It was clarified from the analysis of the electrical and TMR properties of the devices with a nano-layered structure that the giant TMR effect at low temperatures is due to higher-order cotunnleing process, which is related to the granular structure of the films, and, more importantly, due to nearly-complete spin polarization (higher than 80% at zero temperature and bias) of tunneling electrons generated at the interface of Co nanoparticle和C_ <60> -CO化合物。隧道电子的几乎完全完整的自旋极化被认为是在定义良好的颗粒结构条件下实现的当前混合系统的特征性质，并且与设备结构无关。

项目成果

Giant tunnel magnetoresistance in codeposited fullerene-cobalt films in the low bias-voltage regime

• DOI: 10.1063/1.2822397
• 发表时间: 2007-12-10
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Sakai, Seiji;Sugai, Isamu;Maeda, Yoshihito
• 通讯作者: Maeda, Yoshihito

界面スピン変調効果に着目した有機分子/磁性金属スピンバルブの作製

关注界面自旋调制效应的有机分子/磁性金属自旋阀的制备

• 发表时间: 2009
• 作者: Y. Matsumoto;S. Sakai;S. Entani;Y. Takagi;T. Nakagawa;S. Nagamatsu;T. Shimada;H. Naramoto;T. Yokoyama;Y. Maeda;鳴海貴允;Yoshihiro Matsumoto;伊藤賢志;Shiro Entani;境誠司;松本吉弘;松木武雄;境誠司
• 通讯作者: 境誠司

ラマン分光によるグラフェン/磁性金属界面の評価

通过拉曼光谱评估石墨烯/磁性金属界面

• 发表时间: 2009
• 作者: Pergolesi D.;Fabbri E.;Traversa E.;牧原克典;圓谷志郎
• 通讯作者: 圓谷志郎

巨大TMR効果に影響を及ぼすC60-Co化合物の電子/スピン状態(II)

影响巨TMR效应的C60-Co化合物的电子/自旋态（二）

• 发表时间: 2010
• 作者: 松本吉弘;境誠司;圓谷志郎;永松伸一;北條育子;藤川高志;島田敏宏;楢本洋;前田佳均;横山利彦
• 通讯作者: 横山利彦

Magnetic and Magnetotransport Properties in Nanogranular Co/C_<60>-Co Film with High Magnetoresistance

高磁阻纳米颗粒Co/C_<60>-Co薄膜的磁性能和磁输运性能

• 发表时间: 2007
• 期刊: Materials Transactions 48
• 作者: R.Hasunuma;C.Tamura;T.Nomura;Y.Kikuchi;K.Ohmori;M.Sato;A.Uedono;T.Chikyow;K.Shiraishi;K.Yamada;K.Yamabe;Seiji Sakai
• 通讯作者: Seiji Sakai