• Transactions of the Society of Information Storage Systems
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• v.5 no.2
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• pp.58-63
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• 2009

This paper describes the effects of slider behavior over patterned media. The flying characteristics of a slider over patterned media are different from slider flying behavior over conventional plane disk. In order to perform the most realistic simulation of slider flying characteristics over patterned disk surfaces, our simulation approach virtually distributes the grooves on the slider ABS instead of on the disk surface. Also, we define SSFA which is steady-state slider flying attitude. The results show that the more patterned size is small and height is large, the more increased SSFA is. Also if patterned distance is small, then SSFA is increased. In addition, we analyzed the effects of patterned shapes.

• Transactions of the Society of Information Storage Systems
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• v.3 no.3
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• pp.149-153
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• 2007

Perpendicular patterned magnetic media have been regarded as a prime candidate to achieve an ultra-high magnetic recording density of over 1 Tera-bits/$inch^2$. Patterned magnetic media with nanoscale patterns have been fabricated using various nanopatterning technologies. We focused on the two technical issues of nanoinjection molding technology. Firstly, we have investigated a cost-effective method to fabricate metallic stamps. Secondly, we focused on the analysis of nanoinjection molding with passive heating, where the replication of 50 nm nanopillar arrays was successful. The effect of the thermal insulation layer on the replication quality was examined by analytical and experimental methods. Finally, we deposited a magnetic layer on a injection molded nanopillars and measured. Our methodology can provide cost-effective mass-production for patterned magnetic media.

• Transactions of the Society of Information Storage Systems
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• v.3 no.2
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• pp.86-93
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• 2007

In this paper we explain why future probe storage systems will use patterned media. As a model system, magnetic patterned media will be discussed, even though their data density is limited to about $7Tbit/in^2$. The first results on magnetic probe storage on patterned media are presented, and the problem of switching field distribution is discussed in detail. Finally we will present the first steps into two-dimensional coding for patterned media.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.192-196
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• 2005

In this paper, we investigated the possibility of replicating patterned media by nano-injection molding process with a metallic nano-stamper. The original nano-master was fabricated by E-beam lithography and ICP etching process. The metallic nano-stamper was fabricated using a nanoimprint lithography and nano-electroforming process. The nano-patterned substrate was replicated using a nano-injection molding process without additional etching process. In nano-injection molding process, since the solidified layer, generated during the polymer filling, deteriorates transcribability of nano patterns by preventing the polymer melt from filling the nano cavities, an injection-mold system was constructed to actively control the stamper surface temperature using MEMS heater and sensors. The replicated polymeric patterns using nano-injection molding process were as small as 50 nm in diameter, 150 nm in pitch, and 50 nm in depth. The replicated polymeric patterns can be applied to high density patterned media.

• Transactions of Materials Processing
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• v.14 no.9 s.81
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• pp.741-750
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• 2005

• Transactions of Materials Processing
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• v.14 no.7 s.79
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• pp.624-627
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• 2005

In this paper, we investigated the possibility of replicating patterned media by nano-injection molding process with a metallic nano-stamper. The original nano-master was fabricated by I-beam lithography and ICP etching process. The metallic nano-stamper was fabricated using a nanoimprint lithography and nano-electroforming process. Finally, the nano-patterned substrate was replicated using a nano-injection molding process without additional etching process. The replicated patterns using nano-injection molding process were as small as 50nm in diameter, 150nm in pitch, and 50nm in depth.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.60-63
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• 2005

In this paper, we investigated the possibility of replicating patterned media by nano-injection molding process with a metallic nano-stamper. The original nano-master was fabricated by E-beam lithography and ICP etching process. The metallic nano-stamper was fabricated using a nanoimprint lithography and nano-electroforming process. Finally, the nano-patterned substrate was replicated using a nano-injection molding process without additional etching process. The replicated patterns using nano-injection molding process were as small as 50 nm in diameter, 150 nm in pitch, and 50 nm in depth.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.739-743
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• 2013

In this paper, a two-dimensional (2-D) channel code for magnetic patterned media is proposed. Patterned media records an information bit on a magnetized dot. Since the space between adjacent tracks is narrow in order to increase the storage density, inter-track interference (ITI) and inter-symbol interference (ISI) can be problems. The amplitude of a bit signal can be corrupted by the 2-D ISI. The signal of the bit surrounded by the same value can be especially destructive, i.e. when its value is the same as the values of the eight surrounding bits. The proposed modulation coding scheme improves the decoding performance of patterned media by preventing this worst case and provides a better code rate than conventional channel codes.

• Transactions of the Society of Information Storage Systems
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• v.3 no.3
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• pp.144-148
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• 2007

In this paper, we analyzed the effect of the pattern height on the readback signal characteristics of the magnetic nanopillar tops and trench bottoms. In addition, we discuss the applicability of the present method to the production of patterned magnetic media, which can be obtained by depositing magnetic thin films on the molded nanopillars with passive heating. We found that the individual magnetic island deposited on each molded nanopillars with passive heating is a single magnetic domain and confirmed that its magnetization can be successfully reversed by applying an external magnetic field.

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.70-71
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• 2010

In this study, We fabricated FePt-based perpendicular patterned media using a selective combination of E-beam lithography and either Ar plasma etching (deposition-first process) or FePt lift-off (deposition-last process). We employed the deposition-last process to avoid chemical and structural disordering by impinging Ar ions (deposition-first process). For a patterned medium with 100 nm patterns made by this process, the out-of-plane coercivity was measured to be 5 fold larger than its in-plane value. The deposition-last process may be a promising way to achieve ultra-high density patterned media.