Microstructure and magnetic properties of CoPtCr-SiO/sub 2/ perpendicular recording media

Oikawa, T.; Nakamura, Masatoshi; Uwazumi, H.; Shimatsu, T.; Muraoka, H.; Nakamura, Yasuko

doi:10.1109/tmag.2002.801791

Cited by 197 publications

(61 citation statements)

References 5 publications

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“…To realize these requirements, the segregation of oxides material into the grains boundaries and the promotion of phase separation between the oxide and metal material are essential. Generally, for the grain boundary materials, oxides material which do not dissolve into the CoPt metal, such as SiO 2 , 3 8,9 Furthermore, by mixing low T m B 2 O 3 with high T m oxides, media with small magnetic grain size can be obtained. 10 It is also shown that the introduction of a buffer layer (BL) underneath the granular media has a great impact on promoting the intergranular exchange decoupling of the media.…”

Section: Introductionmentioning

confidence: 99%

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Reduction of intergranular exchange coupling and grain size for high Ku CoPt-based granular media: Metal-oxide buffer layer and multiple oxide boundary materials

et al. 2017

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Investigation of magnetic properties and microstructure of granular media with various multiple oxides as the grain boundary material is reported. Saturation magnetization (Ms), uniaxial magnetocrystalline anisotropy (Ku), and magnetic grain diameter (GD) of the granular media show linear correlation with volume weighted average for melting point (Tm) of each oxides (Tmave). Ku of magnetic grains (Kugrain) shows a trade-off relation with GD that it is a big challenge to satisfy both high Kugrain and small GD by only controlling Tmave. To obtain a granular medium with appropriate Kugrain, GD, and low degree of intergranular exchange coupling, the combination of Tmave control of grain boundary material by mixing oxides and employment of a buffer layer are required. Here the degree of intergranular exchange coupling is estimated from the slope of M-H loop at around coercivity (α). By applying this technique, a typical granular medium with Kugrain of 1.0×107 erg/cm3, GD of 5.1 nm, and α of 1.2 is realized.

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Section: Introductionmentioning

confidence: 99%

“…Here the degree of intergranular exchange coupling is estimated from the slope of M-H loop at around coercivity (α). By applying this technique, a typical granular medium with K u grain of 1.0×10 7 erg/cm 3 …”

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confidence: 99%

Reduction of intergranular exchange coupling and grain size for high Ku CoPt-based granular media: Metal-oxide buffer layer and multiple oxide boundary materials

et al. 2017

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“…These materials are exploited in the current perpendicular magnetic recording media, where magnetic CoPt grains with high uniaxial anisotropy are spatially and magnetically isolated by oxide grain boundaries to prevent the magnetizations of adjacent grains from coupling. 19,20 Ruthenium has a hexagonal close packed (HCP) crystal structure with a close lattice matching with HCP CoPt, and thus a coherent Ru-CoPt interface is energetically favored. Further, metal-oxide interfaces are typically higher energy interfaces than metal-metal interfaces.…”

Section: All Article Content Except Where Otherwise Noted Is Licensmentioning

confidence: 99%

Fabrication of bit patterned media using templated two-phase growth

et al. 2017

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In fabricating high areal density magnetic nanostructures for bit patterned magnetic recording media, conventional lithography methods are limited in scaling and often present other challenges, for instance, as etch-damage in case of subtractive schemes. In this paper, we present a novel two-phase growth scheme that enables the fabrication of nanostructures of one material embedded in a matrix of a different material by choosing a separation material that is immiscible with the material of the nanostructure and by designing a template whose material and morphology guides the separation of the two phases and their subsequent growth.

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“…6. Various nonmagnetic materials such as C 90) , SiO2 91) , TiO2 92) , Ta2O5 93 ), etc. have been investigated for magnetic crystal grain isolation of hcp-Co-alloy materials.…”

Section: Introductionmentioning

confidence: 99%

Development of Media Nanostructure for Perpendicular Magnetic Recording

Futamoto

Ohtake

2017

J. Magn. Soc. Jpn.

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The review covers the research and development of perpendicular media nanostructure focusing on the recording layer. The recording layer material includes the Co-alloys with hcp structure, the magnetic multilayers, and the alloys with ordered structures that have high magneto-crystalline anisotropies (Ku). The technologies of underlayer or interlayer for aligning the easy magnetization axis of magnetic crystal grain perpendicular to the film plane are briefly reviewed including the high Ku magnetic materials for future recording media.Observations of compositional and magnetization structures in sub-µm scale have played important roles in improving the recording layer. Typical data on these characteristics are explained in relation to the media structure improvements. Considering that high Ku magnetic materials will be employed in future recording media, basic experimental results related in controlling the easy magnetization axis and in keeping the surface flatness of L10-ordered magnetic materials are explained. Future possibilities for increasing the areal density beyond 1 Tb/in 2 by improving the magnetic material and the nanostructure of recording layer are also discussed.

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Microstructure and magnetic properties of CoPtCr-SiO/sub 2/ perpendicular recording media

Cited by 197 publications

References 5 publications

Reduction of intergranular exchange coupling and grain size for high Ku CoPt-based granular media: Metal-oxide buffer layer and multiple oxide boundary materials

Reduction of intergranular exchange coupling and grain size for high Ku CoPt-based granular media: Metal-oxide buffer layer and multiple oxide boundary materials

Fabrication of bit patterned media using templated two-phase growth

Development of Media Nanostructure for Perpendicular Magnetic Recording

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