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Micro-patterned high-density magnetic recording media by self-assembly in solution

通过溶液自组装形成微图案高密度磁记录介质

基本信息

批准号：
11650343
负责人：
KITAMOTO Yoshitaka
金额：
$ 2.37万
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 (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

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.

该报告描述了通过溶液中的自组装过程制备用于高密度磁记录介质的纳米颗粒阵列。将反胶束技术制备磁性纳米颗粒与自组装排列颗粒相结合。发现在60℃以下的低温下制备铁氧体颗粒的pH值向较高范围移动，这是采用反胶束技术的最高温度。在合成磁铁矿或钴铁氧体颗粒的结晶度和颗粒尺寸方面，氨溶液优于NaOH溶液。在25~55℃范围内，反应温度对颗粒尺寸和结晶度没有影响，但饱和磁化强度随着温度的升高而增加。然而，本研究中获得的各种颗粒在室温下都表现出超顺磁性。在颗粒中添加Co离子提高了5 K时的矫顽力，并且最大值高于10 kOe。然而，钴铁氧体颗粒仍然具有超顺磁性。平均粒径约为10nm。透射电子显微镜(TEM)观察和纳米束电子衍射图表明，单个颗粒为单晶。TEM观察表明，一些平均尺寸为10 nm的颗粒聚集在一起，而另一些较小尺寸的颗粒则分布不聚集。这一结果表明，具有均匀尺寸的颗粒倾向于彼此聚集。换句话说，颗粒可能通过自组装过程以相似的尺寸进行排序。这种趋势对于制造具有均匀颗粒的阵列有影响。尝试借助自组装有机分子对宽度为2毫米、间距为4毫米的颗粒薄膜进行微图案化，以制造图案化磁记录介质。然而，图案的质量不如仅有机分子的薄膜。