2000 Fiscal Year Final Research Report Summary
Micro-patterned high-density magnetic recording media by self-assembly in solution
| Project/Area Number |
11650343
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電子デバイス・機器工学
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
KITAMOTO Yoshitaka Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Associate Professor, 大学院・総合理工学研究科, 助教授 (10272676)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Masanori Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor, 大学院・理工学研究科, 教授 (70016624)
TANIYAMA Tomoyasu Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Research Associate, 大学院・総合理工学研究科, 助手 (10302960)
YAMAZAKI Yohtaro Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Professor, 大学院・総合理工学研究科, 教授 (50124706)
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| Project Period (FY) |
1999 – 2000
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| Keywords | ferrite thin films / reverse micelle / magnetic nanoparticles / ferrite plating / micro-patterning |
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| Research Abstract |
This report describes the preparation of a nanoparticles array for high-density magnetic recording media by a self-assembly process in a solution. Reverse micelle technique for preparing magnetic nanoparticles and self-assembly for arraying the particles were combined.
It was found that pH values for preparing ferrite particles moved to higher range at low temperature below 60℃, which is the maximum temperature to employ the reverse micelle technique. An ammonia solution was superior to a NaOH solution regarding crystallinity and particle size for synthesizing magnetite or Co ferrite particles. While reaction temperature did not influence the particle size and crystallinity in the range from 25 to 55℃, saturation magnetization increased with increasing the temperature. However, all kinds of the particles obtained in this study exhibited super-paramagnetic properties at room temperature. Adding Co ions to the particles increased coercivity at 5 K, and the maximum value was higher than 10 kOe. However, the Co ferrite particles were still super-paramagnetic. Average particle size was about 10 nm. Transmission electron microscope (TEM) observation and electron diffraction pattern with nano-sized beam showed that a single particle was single crystal.
TEM observation showed that some particles with the average size of 10 nm assembled and the others with the smaller size distributed without assembling. This result suggests that particles with a uniform size tend to assemble each other. In other words, the particles probably sort themselves with the similar size by self-assembling process.
This tendency has an effect on manufacturing the array with uniform particles. Micropatternig of particulate films with the width of 2 mm and the pitch of 4 mm were tried with the help of self-assembling organic molecules in order to fabricate patterned magnetic recording media. However, the quality of the pattering was not as good as that of films of only the organic molecules.
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