Development of high frequency soft magnetic thin films consisting of ferromagnetic alloy/ferromagnetic insulator multi-phase granular materials

铁磁合金/铁磁绝缘体多相颗粒材料高频软磁薄膜的研制

• 批准号: 07555211
• 负责人: FUJIMORI Hiroyasu
• 金额: $ 13.25万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555211/
• 关键词: magnetic thin film; nano-granular film; soft magnetic properties; high frequency magnetic materials; high electrical resistivity; eddy current loss; ferrite; sputtering; 磁性薄膜; グラニュラー合金; 薄膜; 透磁率; 電気抵抗; 磁気異方性

As small sizing and high frequency use of magnetic devices are extensively required nowadays, it is an important subject in the research field of magnetic materials to fabricate magnetic thin films with high saturation magnetization and high electrical resistivity. Nanogranular thin films consisting of magnetic metal and nonmagnetic insulator have been investigated so far, and fairly good soft magnetic properties (resistivity rho=100-500 muOMEGAcm, saturation magnetization Bs-10 kG) were achieved. However, further investigation and development of soft magnetic thin films with high electrical resistivity are currently required for applications such as high density magnetic recording heads etc. In this research project, we have investigated soft magnetic properties and electrical resistivity behavior of ferromagnetic alloy/ferromagnetic insulator multi-phase granular thin films.Granular thin film samples were prepared by a sputtering technique with composite targets of ferromagnetic alloy and ferromagnetic insulator, and microstructure, electrical resistivity and magnetic properties were examined. From a systematic investigation for many kinds of combinations of ferromagnetic alloys and ferromagnetic insulators, we found that it is important to control surface reaction of ferromagnetic insulator on the film surface. Also, we found that Fe-MgFe_2O_4 and Ni-MgFe_2O_4 systems are candidates for very good soft magnetic thin films with high saturation magnetization and high electrical resistivity. For Fe-Mg-O multi-phase granular systems, good results, such as rho=100-400 and Bs=12-16 kG,were obtained in the optimized sputtering condition.In addition to the results mentioned above, soft magnetic thin films of Co-Fe-Al-O exhibiting very high saturation magnetization (Bs=19 kG) has been achieved although its resistivity is fairly low( rho=100 muOMEGAcm) . It is considered that the Co-Fe-Al-O film can be used for application of high density magnetic recording heads.

随着磁性器件小型化、高频率使用的广泛要求，制备高饱和磁化率、高电阻率的磁性薄膜是磁性材料研究领域的一个重要课题。磁性金属和非磁性绝缘体组成的纳米颗粒薄膜目前已经得到了相当好的软磁性能（电阻率rho=100-500 μ m，饱和磁化Bs-10 kG）。然而，高密度磁记录磁头等应用需要进一步研究和开发具有高电阻率的软磁薄膜。本课题研究了铁磁合金/铁磁绝缘体多相颗粒薄膜的软磁性能和电阻率特性。以铁磁合金和铁磁绝缘体为复合靶材，采用溅射法制备了颗粒状薄膜样品，并对其微观结构、电阻率和磁性能进行了测试。通过对多种铁磁合金与铁磁绝缘子组合的系统研究，我们发现控制铁磁绝缘子在薄膜表面的表面反应是非常重要的。此外，我们还发现Fe-MgFe_2O_4和Ni-MgFe_2O_4体系是具有高饱和磁化强度和高电阻率的非常好的软磁薄膜的候选材料。对于Fe-Mg-O多相颗粒体系，在优化的溅射条件下获得了良好的溅射效果，rho=100-400, Bs=12-16 kG。除了上述结果外，还获得了具有很高饱和磁化强度（Bs=19 kG）的Co-Fe-Al-O软磁薄膜，尽管其电阻率相当低（rho=100 muOMEGAcm）。认为Co-Fe-Al-O薄膜可用于高密度磁记录磁头。

项目成果

S.Ohnuma: "Co-(N or O)based granular thin films and their magnetic properties" Joumal of Alloys and Compounds. 222. 167-172 (1995)

S.Ohnuma：“Co-（N 或 O）基颗粒薄膜及其磁性”合金和化合物杂志。

大沼 繁弘: "高電気抵抗軟磁性薄幕の開発の現状" 電気学会マグネティクス研究会資料. MAG-97-2. 3-8 (1997)

Shigehiro Onuma：“高电阻软磁薄幕的开发现状”日本电气工程师学会磁学研究小组的材料MAG-97-2（1997）。

S.Ohnuma, S.Mitani, H.Fujimori and T.Masumoto: "Soft magnetic properties at high frequencies of Co-Al-O films with granular structure" J.Mag.Soc.Jpn. 20. 489-492 (1996)

S.Ohnuma、S.Mitani、H.Fujimori 和 T.Masumoto：“具有粒状结构的 Co-Al-O 薄膜的高频软磁性能”J.Mag.Soc.Jpn。

H.Fujimori: "Soft magnetic materials" J.Mag.Soc.Jpn. 21. 99-106 (1997)

H.Fujimori：“软磁材料”J.Mag.Soc.Jpn。

小林 伸聖: "Fe-X-O(X=Y, Nd, Sm, Gd, Tb, Dy)系高電気抵抗膜の軟磁気特性" 日本応用磁気学会誌. 20(in press). (1996)

Nobuaki Kobayashi：“基于 Fe-X-O(X=Y、Nd、Sm、Gd、Tb、Dy) 的高电阻薄膜的软磁性能”，日本应用磁学学会杂志 20（出版中）。