Fabrication of magnetic nanoparticle-array recording media and their evaluation with probe heads

磁性纳米颗粒阵列记录介质的制备及其探针头的评估

• 批准号: 14350180
• 负责人: KITAMOTO Yoshitaka
• 金额: $ 10.88万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350180/
• 关键词: Magnetic recording medium; Magnetic nanoparticle; Self-assembly; Nanoparticle array; Magnetic anisotropy; Ordered alloy; Fe-Pt; ナノ粒子; ラングミュア・プロジェット法; ラングミュア・ブロジェット法; FePt; 磁気緩和; LB法

The purpose of the present study is to establish fabrication techniques of Fe-Pt nanoparticle-array magnetic recording media and to evaluate their potential to achieve areal recording density over 1 tera-bit per square inch. The results are shown in the followings.1) We studied the relationship between chemical ordering and magnetic anisotropy for powder samples of Fe-Pt nanoparticles, and found that a volume ratio Q of ordered alloy phase evaluated with Mossbauer spectroscopy was a useful parameter to evaluate the chemical ordering. Whereas Q is a parameter for short-range ordering, S obtained from X-ray diffractometry is a parameter for long-range ordering. Magnetic anisotropy was evaluated with the maximum magnetic field of 90 kOe. Distribution of magnetic anisotropy-field H_k for partially ordered Fe-Pt nanoparticles was much broader than that for almost fully ordered Fe-Pt nanoparticles, and the low H_k components were included with a high volume ratio.2) Partially ordered Fe-Pt n … More anoparticles were successfully obtained with polyol reduction method of Fe and Pt salts by using microwave irradiation without any post-synthesis heat-treatment. The Fe-Pt nanoparticles synthesized at 250℃ with microwave irradiation exhibited volume ratio for ordered alloy phase of 60% and magnetic anisotropy field over 80 kOe.3) Mixing saturated fatty acid (C_nH_<2n> O_2) molecules to an Fe-Pt nanoparticle suspension assisted the formation of a nanoparticle monolayer on pure water surface without coagulation. Because the surface of the Fe-Pt nanoparticles is hydrophobic, interface energy with water surface is high. The fatty acid molecules probably reduced the interface energy as a buffer layer between the Fe-Pt nanoparticle-monolayer and water surface. Fatty acid molecules with n 【greater than or equal】 14 were effective for the formation, and the best one in view of the formation of regular nanoparticle-array was the molecule with n = 14.4) Carbon overcoats deposited with sputtering on Fe-Pt nanoparticle assembly-films successfully prevented the assembly-films from inter-particle sintering. Fe-Pt nanoparticles of 4-5 nm in diameter were kept isolated physically and were chemically ordered after an optimum heat-treatment. However, higher temperature and longer time for the heat treatment were required to achieve proper chemical ordering to fit a specification of high-density recording media for future recording system. Fe-Pt nanoparticle assembly-films with a carbon overcoat annealed under the optimum conditions exhibited that the particle size was 4-5 nm and magnetic anisotropy constant was 4.8x10^7 erg/cm^3. Less

本研究的目的是建立Fe-PT纳米颗粒阵列磁性记录介质的制造技术，并评估其在每平方英寸1 TERA-TERA位置以上实现面积记录密度的潜力。结果在以下显示。1）我们研究了Fe-PT纳米颗粒的粉末样品化学秩序与磁各向异性之间的关系，并发现使用摩斯鲍尔光谱评估的有序合金相的体积比Q是评估化学序列的有用参数。 Q是用于短距离排序的参数，而从X射线衍射测量法获得的S是用于远程排序的参数。用90 KOE的最大磁场评估磁各向异性。对于部分有序的Fe-PT纳米颗粒的磁各向异性场h_k的分布比几乎完全有序的Fe-PT纳米颗粒的分布要宽得多，而低的H_K组件则包括高体积比，高体积比。2）部分有序的Fe-PT n…通过使用polyol还原saldiatir saldiation获得了较高的fe-ppt n，而不是py salys salys salys salad salad salad salad salad salad salad salad salad salad salad salad salad salad salad salad nanoppticts nanopiate。热处理。 The Fe-Pt nanoparticles synthesized at 250℃ with microwave irradiation exposed volume ratio for ordered alloy phase of 60% and magnetic anisotropy field over 80 kOe.3) Mixing saturated fatty acid (C_nH_<2n> O_2) molecules to an Fe-Pt nanoparticle suspension assisted the formation of a nanoparticle monolayer on pure water surface without coagulation.由于Fe-PT纳米颗粒的表面是疏水，因此与水面的界面能量很高。脂肪酸分子可能会降低界面能量，作为Fe-PT纳米颗粒单层和水面之间的缓冲层。 N [大于或相等] 14的脂肪酸分子对于形成是有效的，鉴于常规纳米颗粒阵列的形成是最好的脂肪酸分子，是n = 14.4）的分子，其碳大衣沉积并在Fe-ptt纳米颗粒组件上溅射，成功地阻止了组装纤维的组合膜，从而使组合细胞织物插入了互构层。直径为4-5 nm的Fe-pt纳米颗粒物理分离，并在最佳的热处理后化学排序。但是，需要更高的温度和更长的热处理时间才能实现适当的化学订购，以适合未来记录系统的高密度记录介质的规范。 Fe-pt纳米颗粒组件具有带有碳大衣的最佳条件下粒径为4-5 nm，磁各向异性常数为4.8x10^7 erg/cm^3的最佳条件。较少的

项目成果

H.Sakuma, H.Nishio, Y.Kitamoto, et al.: "High-Field Torque Measurement of FePt Nanoparticles"Trans.Magn.Soc.Japan. 4,[1]. 24-27 (2004)

H.Sakuma、H.Nishio、Y.Kitamoto 等人：“FePt 纳米颗粒的高场扭矩测量”Trans.Magn.Soc.Japan。

Direct Synthesis of L10 Type Fe-Pt Nanoparticles by Microwave-Polyol Method

微波-多元醇法直接合成L10型Fe-Pt纳米粒子

• 发表时间: 2005
• 期刊: Electrochimica Acta vol.51,[5]
• 作者: R.Minami;Y.Kitamoto;T.Chikata;S.Kato
• 通讯作者: S.Kato

H.Sakuma, T.Taniyama, H.Nishio, Y.Kitamoto, et al.: "Anisotropy Field Distribution of Partially Ordered Fe-Pt Nanoparticles"J.Appl.Phys.. (印刷中). (2004)

H.Sakuma、T.Taniyama、H.Nishio、Y.Kitamoto 等人：“部分有序 Fe-Pt 纳米粒子的各向异性场分布”J.Appl.Phys.（出版中）。

High-Field Torque Measurement of FePt Nanoparticles

FePt 纳米颗粒的高场扭矩测量

• 发表时间: 2004
• 期刊: Trans.Magn.Soc.Japan vol.4,[1]
• 作者: H.Sakuma;H.Nishio;Y.Kitamoto;Y.Yamazaki;H.Yamamoto
• 通讯作者: H.Yamamoto

FePt Nanoparticle-assembly for Magnetic Recording Media

用于磁记录介质的 FePt 纳米颗粒组装体

• 发表时间: 2003
• 期刊: Magnetic Materials, Processes, and Devices VII and Electrodeposition of Alloys
• 作者: Yoshitaka Kitamoto;Hiroshi Sakuma;Arata Jogo;Tomoyasu Taniyama;Yohtaro Yamazaki
• 通讯作者: Yohtaro Yamazaki