-
[show abstract]
[hide abstract]
ABSTRACT: Discrete track recording has emerged as a promising candidate for high storage capacity since it reduces adjacent track erasing (ATE) and alleviates narrow head requirements. In this paper, the writability of discrete lines was studied in discrete track media (DTM) fabricated by e-beam lithography and ion-milling on perpendicular magnetic recording (PMR) media. The writability of discrete lines with finite length and three kinds of line width (50, 100, and 150 nm) is compared with continuous media on the same track. When writing current is small (less than 12 mA), the narrowest discrete lines (50 nm) are not easily magnetized, most likely due to deformed magnetic layer created by a shallow wall angle. Conversely, wider discrete lines ( ges 100 nm) are magnetized like continuous media. No difference in the level of magnetization was observed for the narrowest lines if writing current was large enough (more than 12 mA). This smooth magnetization of the narrowest line at sufficient writing current flow makes it certain that narrow discrete line can be used for high capacity storage.
IEEE Transactions on Magnetics 12/2008; · 1.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report on fabrication of discrete tracks on perpendicular magnetic recording (PMR) media with an e-beam lithographical process. We studied the recording performance of the e-beam media on a spinstand in parallel with conventional PMR media. Discrete track media show significant reduction in adjacent track erasure (ATE). We studied and quantitatively measured the source of the ATE improvement, and developed a triple track geometrical model to calculate achievable track density for both discrete track recording (DTR) and continuous media. From the model, we identify two factors of DTR that contribute to reaching a higher TPI. Using the same fabrication technique, we also studied servo burst design and its playback waveform quality. At 250 ktpi, we compare DTR servo bursts with servo bursts written with a conventional method. DTR servo bursts show better edge definition, which can translate to better position error signal sensitivity and support higher TPI in the future.Discrete tracks are fabricated on conventional PMR media with an e-beam litho graphical process. The recording performance is studied on a spinstand in parallel with conventional PMR media. Discrete track media shows significant reduction in adjacent track erasure (ATE). The source of the ATE improvement is studied and quantitatively measured. A triple track geometrical model is developed to calculate achievable track density for both DTR and continuous media. From the model, we identify two factors of DTR, which contribute to reaching a higher TPI. Using the same fabrication technique, we also study servo burst design and its playback waveform quality. At 250 ktpi, we compare DTR servo bursts and servo bursts written with a conventional method. DTR servo bursts show better edge definition, which can translate to better PES signal sensitivity and support higher TPI in the future.
IEEE Transactions on Magnetics 01/2008; · 1.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Discrete track recording technology offers a potential advantage in reducing adjacent track erasure/interference. As nano-imprinting technology advances, fabrication of such media has been demonstrated. In recent years, discrete track recording has generally been viewed as one of the next promising technologies for areal density advancement. In this study, we evaluated the recording performance of PMR media with patterned tracks. To accurately assess the advantage of discrete track performance and compare with current continuous media, both recording performances were measured on one single track. The head flying height is monitored on the patterned and continuous media regions. At 100-nm data track width, patterned tracks show noticeably better signal-to-noise ratio and significantly lower adjacent track erasure compared with continuous media at the same track width. Such measured performance advantages are critical to increase track density beyond 300-400 ktpi
IEEE Transactions on Magnetics 07/2007; · 1.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Discrete track media offers many potential recording advantages over conventional continuous media in hard disk drives. In this study, we present a novel fabrication process for discrete track perpendicular magnetic media via electron beam lithography, ion milling, and the use of a protective Al sacrificial layer. Physical characterization of the media confirms the process is able to produce patterned tracks with no damage to the media. Spin stand analysis verifies the disks are flyable and capable of recording sharp transitions without any degradation in the magnetic signal
IEEE Transactions on Magnetics 07/2007; · 1.36 Impact Factor
