Development of magnetic nanoparticle recoding media via chemical template assisted self-assembly

通过化学模板辅助自组装开发磁性纳米颗粒记录介质

• 批准号: 17360152
• 负责人: OGAWA Tomoyuki
• 金额: $ 9.73万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360152/
• 关键词: Magnetic nanoparticle; Self assembly; Magnetic recording media; Nanoparticle with uniaxial anisotropy; Di-block polymer; Adsorption; Control of crystallographic orientation

Fabrication technique for ferromagnetic nanoparticles such as FePt alloy array structure via patterned template assisted self-assembly has been developed for possible application to magnetic recording media over 1Tbit/in^2. We tried to chemically synthesize L1_0-FePt nanoparticles by optimizing the synthesis condition in the post-annealing procedure of the fcc-FePt seeds. As a result, partially ordered L1_0-FePt nanoparticles with volume fraction of 50% were successfully obtained under high-temperature and strong reduction conditions without any surfactant. In addition, in order to obtain magnetic nanoparticles with uniaxial magnetic anisotropy with high volume fraction, we have developed the quantitative characterization technique of decomposition rate of Co precursors in the synthesis using IR spectra and successfully synthesized hcp-Co nanoparticles with volume fraction of 70-80% under slow decomposition rate condition.We have also fabricated the mono-layered nanoparticle periodic array structure with highly oriented crystallographic c-axis of the nanoparticles by applying chemical/physical adsorption between nanoparticle and substrate. As a result, electro-chemically modification of the substrate surface using scanning probe microscopy technique has realized selective deposition of FePt nanopaticles, resulting in 0.1 Tdots/in^2 of the FePt nanoparticle dots. Furthermore, by applying di-block co-polymer template substrate, selective deposition of one nanoparticle was realized on one hydrophobic dot. And the c-axis oriented nanoparticle array structure was partially obtained by applying external magnetic field.

利用模版辅助自组装技术制备铁磁性纳米颗粒，如FePt合金阵列结构，有望应用于1Tbit/in^2以上的磁记录介质。我们试图通过优化fcc-FePt种子后退火过程中的合成条件，化学合成L1_0-FePt纳米粒子。结果表明，在不添加表面活性剂的高温强还原条件下，成功制备了体积分数为50%的部分有序L1_0-FePt纳米颗粒。此外，为了获得具有高体积分数的单轴磁各向异性磁性纳米颗粒，我们开发了利用红外光谱定量表征合成中Co前驱体分解速率的技术，并在慢分解速率条件下成功合成了体积分数为70-80%的hcp-Co纳米颗粒。我们还利用纳米颗粒与衬底之间的化学/物理吸附，制备了具有高取向c轴的单层纳米颗粒周期阵列结构。结果，利用扫描探针显微镜技术对衬底表面进行电化学修饰，实现了FePt纳米颗粒的选择性沉积，得到了0.1 Tdots/in^2的FePt纳米颗粒点。此外，利用双嵌段共聚物模板衬底，实现了一个纳米粒子在一个疏水点上的选择性沉积。外加磁场可获得部分c轴取向纳米粒子阵列结构。

项目成果

Topics : Synthesis of superparamagnetic nanoparticle assembly and its dynamic magnetic properties in high-frequency range

主题 : 超顺磁性纳米粒子组装体的合成及其高频动态磁性能

• 发表时间: 2006
• 期刊: VIAGUNE Vol.1-No.12
• 作者: H.Fujisawa et al.;H.Fujisawa et al.;H.Fujisawa et al.;清水 勝 他;Hironori Fujisawa;M.Okaniwa;H.Fujisawa;M.Okaniwa et al.;H.Fujisawa et al.;Mamoru Okaniwa;Y.Li;Y.Li;T.Ogawa;小川智之;H.T.Yang;D.Hasegawa;M.Yokoyama;T.Ogawa;T.Ogawa
• 通讯作者: T.Ogawa

Magnetic Fe nanoparticles inserted into single-walled carbon nanotubes

插入单壁碳纳米管的磁性铁纳米颗粒

• 发表时间: 2007
• 期刊: Chemical Communications
• 影响因子: 4.9
• 作者: H.Fujisawa et al.;H.Fujisawa et al.;H.Fujisawa et al.;清水 勝 他;Hironori Fujisawa;M.Okaniwa;H.Fujisawa;M.Okaniwa et al.;H.Fujisawa et al.;Mamoru Okaniwa;Y.Li
• 通讯作者: Y.Li

Heterogeneous Nucleation Synthesis of monodisperse ε-Cobalt Nanoparticles Using Palladium Seeds

使用钯种子异相成核合成单分散 ε-钴纳米颗粒

• 发表时间: 2006
• 期刊: Journal of Magnetism and Magnetic Material 304巻
• 作者: H.Fujisawa et al.;H.Fujisawa et al.;H.Fujisawa et al.;清水 勝 他;Hironori Fujisawa;M.Okaniwa;H.Fujisawa;M.Okaniwa et al.;H.Fujisawa et al.;Mamoru Okaniwa;Y.Li;Y.Li;T.Ogawa;小川智之;H.T.Yang
• 通讯作者: H.T.Yang

Large magnetoresistance (>600%) of a GaAs:MnAs granular thin film at room temperature

• DOI: 10.1063/1.2151817
• 发表时间: 2006-04
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: M. Yokoyama;T. Ogawa;A. M. Nazmul;Masaaki Tanaka

Magnetization reversal mechanism of soft magnetic underlayer pinned by antiferromagnetic layer

反铁磁层钉扎软磁底层的磁化反转机制

• 发表时间: 2005
• 期刊: Journal of Magnetism and Magnetic Materials 287巻
• 作者: H.Fujisawa et al.;H.Fujisawa et al.;H.Fujisawa et al.;清水 勝 他;Hironori Fujisawa;M.Okaniwa;H.Fujisawa;M.Okaniwa et al.;H.Fujisawa et al.;Mamoru Okaniwa;Y.Li;Y.Li;T.Ogawa;小川智之;H.T.Yang;D.Hasegawa;M.Yokoyama;T.Ogawa;T.Ogawa;D.Hasegawa;A.Hashimoto
• 通讯作者: A.Hashimoto