2002 Fiscal Year Final Research Report Summary
The Effects of third Element for Hexagonal Ferrite Thin Films for High Density Magnetic Recording Medium with small grains
| Project/Area Number |
12450124
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Shinshu University |
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Principal Investigator |
MORISAKO Akimitsu Shinshu University, Faculty of Engineering, Professor, 工学部, 教授 (20115380)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEI Shigeto Shinshu University, Faculty of Engineering, Assistant, 工学部, 助手 (50262689)
MATSUMOTO Mitsunori Shinshu University, Faculty of Engineering, Professor, 工学部, 教授 (80020981)
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| Project Period (FY) |
2000 – 2002
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| Keywords | perpendicular recording / hexagonal ferrite thin film / thin film recording media / sputtering / Barium ferrite / Strontium ferrite / magnetic recording / high density recording |
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| Research Abstract |
For an ultra high density perpendicular magnetic recording, the media should have chemical stability, mechanical durability, moderate hard magnetic properties, and small grains. In this study, the effects of third element and under-layer for sputtered hexagonal ferrite thin films on crystallographic characteristics, magnetic properties, and morphological structure were studied. It was found that Bi addition was effective to reduce the grain size and coercivity was about 3.7 kOe. The linear recording density for this film was 210 to 230 kfrpi. In perpendicular recording media, it is very important to prepare the film with perpendicular orientation of magnetic easy axis, which is c-axis in hexagonal ferrite. To promote c-axis orientation, hexagonal A1N with c-axis perpendicular orientation was used as an under-layer. The gain size was reduced to about 40 ma and coercivity as high as 4.3 kOe was obtained, while diffusion of N into hexagonal ferrite layer was found. New under-layer of amorphous aluminum oxide was used for the reduction of grain size and for the magnetically grain isolation. It was found that amorphous aluminum uader-layer could reduce the grain to 20 im and coercivity of this film was about 4 kOe. Magnetic coupling of this film was magneto-static and magnetic cluster size, which was evaluated from MFM observation, was about 40 nm.
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