2004 Fiscal Year Final Research Report Summary
STUDY ON NANO-STRUCTURIZATION AND MAGNETICAL ISOLATION OF Sm-Co MAGNETIC THIN FILMS FOR ULTRA-HIGH DENSITY INFORMATION STORAGE APPLICATION
| Project/Area Number |
14350162
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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 |
MATSUMOTO Mitsunori SHINSHU UNIVERSITY, FACULIY OF ENGINEERING, PROFESSOR, 工学部, 教授 (80020981)
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| Co-Investigator(Kenkyū-buntansha) |
MORISAKO Akimitsu SHINSHU UNIVERSITY, FACULIY OF ENGINEERING, PROFESSOR, 工学部, 教授 (20115380)
TAKEI Shigeto SHINSHU UNIVERSITY, FACULIY OF ENGINEERING, RESEARCH ASSOCIATE, 工学部, 助手 (50262689)
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| Project Period (FY) |
2002 – 2004
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| Keywords | SmCo_5 film / magnetic storage media / perpendicular magnetic anisotropy / seed layer / high coercive magnetic film / perpendicular recording |
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| Research Abstract |
SmCo_5 alloy(here after referred simply as "SmCo") possesses the largest crystalline magnetic anisotropy constant of all magnetic materials, so that it can retain remanent magnetization without demagnetization to compare the other materials if the magnetization switching volume, grain size or the size of grain agglomeration of grain cluster, is reduced for high density storage. The consideration is taken which is more suitable storage media for high density storage of the regime 100-200Gb/in^2 between the high M_s materials as SmCo, NdFeB, FePt and the lower M_s materials as Ba-ferrite. The result is that the high M_s materials are suitable if the grain size and magnetic layer thidcness of media can be reduced to 10nm or less. Since the perpendicularly stored magnetization has much narrower magnetization transition length, the higher M_s generates the higher readout voltage.
To generate the SmCo films with perpendicular magnetic anisotropy, the incorporation of Cu sublayer is effective.
… More
The diffusion of Cu combine with Sm atoms whim protects the oxidation of SmCo layer ; The great merit is that SmCo films ca do without the protective layer for oxidation proof. The analysis of magnetization mechanism shows that magnetization charge is due to the coherent rotation of single-domain magnetization. On the other hand, to generate the SmCo films with planer magnetic anisotropy, the incorporation of Cr sublayer is effective. The magnetization change is due to the wall motion. No other affective element is found except Cu and Cr. To bring out exaggeratedly the perpendicular anisotropy for SmCo film, it is most suitable to use both Cu and Cr layers in the construction of SmCo/Cu/Cr. SEM observation on the SmCo film surface reveals the grain size of 20-100nm TEM observation reveals grains of around 10nm constitute clusters. The analysis of magnetization reversal obtained by the plot of dH/dt vs. H_c and XRD analysis calculated with Scherrer's equation concluded that the magnetization change of SmCo films is caused mainly by magnetization reversal of single domain partides with around 10nm in size. Less
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Research Products
(11 results)
