Thermal Layers Effect on Recording Performance in HAMR

Valcu, B.; Seki, T.; Чернышов, А. В.; Zong, Fenghua; Ajan, Antony

doi:10.1109/tmag.2014.2331282

Cited by 4 publications

(2 citation statements)

References 5 publications

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“…People are designing different types of NFT to increase its efficiency and lifetime [76,[118][119][120]. In addition, tremendous efforts are spent on media design to improve the SNR and AD [56,60,75,111,119,[121][122][123][124][125][126][127][128][129][130][131][132][133][134]. Besides the head and media design, another major factor affection the thermal profile is the NFT tip to media spacing (NMS) [105,135,136].…”

Section: Discussionmentioning

confidence: 99%

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Servo pattern enhancements for high areal density hard disk drives

Kun¹

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The growth of areal density (AD) in hard disk drive (HDD), which measures the data bits per unit area, has slowed down considerably in recent years from the average of 30% annual increase rate achieved in past decades. The main reason is that the current perpendicular magnetic recording (PMR) technology has reached its bottleneck of the so-called superparamagnetism. In the meantime, HDD is facing a strong competition and high market share challenge from solid state drive (SSD). As a result, HDD industry is striving to improve the AD with a few technologies such as shingled magnetic recording (SMR), two-dimensional magnetic recording (TDMR), heat-assisted magnetic recording (HAMR) and bit patterned media (BPM). Among all of these, HAMR is the most viable and promising technology to bring the AD beyond a few terabyte/in 2 level in the coming decade. When the AD is > 1 terabyte/in 2 , the track width is expected to be smaller than a few tens of nanometers. Being a mechanical device, ever decreasing track width has imposed more stringent requirements on the servo system for the better track-following performance of read and write operations. This thesis first focuses on writing good quality servo patterns such as burst field and repeatable run-out (RRO) compensation field under HAMR writing conditions. The HAMR writing mechanism is fundamentally different from the PMR. For PMR, the written-in signal quality is mainly determined by the strength and the gradient of the writing magnetic field. However, for HAMR, although the writing magnetic field is important, the dominating factor for recording quality is determined by the media thermal profile. The media thermal profile is in turn determined by the thermal properties of the media stack and the thermal power delivered to the media. Given the write head design, and especially the near field transducer (NFT), the thermal power delivered to the media can be controlled through input laser power and the spacing between the NFT and the media. Unfortunately, the NFT-to-media

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Section: Discussionmentioning

confidence: 99%

“…The heat sink layer must be designed to balance between the temperature gradient and the lifetime of the NFT. It is because more laser power will be needed to heat up the media to the same temperature level of the smaller heat sink [75].…”

Section: Media For Hamrmentioning

confidence: 99%