Hgst Netherlands, B.v.

Seagate Technology Incorporated

Hitachi Global Storage Technologies Netherlands B.v.

Western Digital Technologies, Inc.

International Business Machines Corporation

Bruno Jean Marchon

Xing-Cai Guo

Qing Dai

Robert Waltman

Jing Gui

Thomas Edward Karis

John Martin Burns

Zine-Eddine Boutaghou

Erhard Theodor Schreck

Chiao-Ping (Roger) Ku

Bala Krishna Pathem

Wei Hsin Yao

Daryl J Pocker

Nicholas R Conley

Thomas R Albrecht

Katsumi Mabuchi

Huan H Tang

Ullal Vasant Nayak

Hong Deng

Malika Dothresa Carter

Mina Amo

David S Kuo

Cyril Guyot

Kurt A Rubin

Dallas W Meyer

Ferdinand Hendriks

Bernhard E Knigge

Peter Raymond Segar

Ricardo Ruiz

Charles Allan Brown

Tsai-Wei Wu

Samuel John Falcone

David Shiao-Min Kuo

Charles Mathew Mate

Run-Han Wang

Toshiki Hirano

Zvonimir Z Bandic

Bruce Alexander Wilson

Luiz M Franca-Neto

Michael Joseph Stirniman

Michael Grobis

Lidu Huang

Sukumar Rajauria

Norbert A Feliss

Li-Ping Wang

Bing K Yen

Ramesh Sundaram

Joel William Hoehn

Roger William Wood

Hoa Van Do

Daniel Paul Burbank

Shanlin Duan

Hiroshi Yoshida

John L Brand

Kentaro Takano

Roger Alan Resh

Mary Cynthia Hipwell

Adam Manzanares

Andreas Argyros Polycarpou

Joseph Cheng-Tsu Liu

Dale E Egbert

Dan Saylor Kercher

Richard Longstreth White

David Gerard Wobbe

Subrahmanyan Nagarajan

Qi-Fan Xiao

Jeffery K Berkowitz

Sripathi Vangipuram Canchi

Kazuhiro Saito

Jizhong He

Franck Rose

Franck Dreyfus Rose Dit Rose

Yun-Lin Hsiao

Yuh-Jen Cheng

Christopher Ramm

Wong K Richard

Xueqian Kong

Michael Andrew Scarpulla

A lubricant including a plurality of segments including a divalent center segment and two sidechain segments, each including a perfluoroalkyl ether moieties is provided in which a dewetting thickness of the lubricant may be determined based in-part on a segment weight average molecular weight of the segments. A magnetic recording medium and a magnetic data storage system including the lubricant are also provided.

Lubricants and methods to determine dewetting thickness thereof

In one embodiment, a method for forming a substantially monodisperse lubricant includes: providing a plurality of perfluoropolyether (PFPE) precursors, each PFPE precursor including two end segments and a PFPE backbone disposed therebetween; protecting one of the end segments of each PFPE precursor with one or more protecting agents to form a plurality of mono-protected PFPE precursors, each mono-protected PFPE precursor including a protected end segment and an unprotected end segment; and coupling the unprotected end segment of each of the mono-protected PFPE precursors to the unprotected end segment of another of the mono-protected PFPE precursors via a coupling agent to form multidentate PFPE structures. In another embodiment, a substantially monodisperse lubricant includes a plurality of multidentate perfluoropolyether (PFPE) structures, each multidentate PFPE structure including at least two end segments and a middle segment therebetween, wherein the multidentate PFPE structures have a molecular weight that is substantially the same.

Monodisperse lubricant including multidentate perfluoropolyether structures

According to one embodiment, a lubricant includes a multidentate perfluoropolyether having a chemical structure of: R&#x2014;R&#x2014;R&#x2014;R&#x2014;R&#x2014;R&#x2014;R, where Rincludes at least one perfluoroethyl ether unit, and where Rand Reach include at least one functional group configured to attach to a surface. According to another embodiment, the aforementioned lubricant may be suitable for use in a sub-nanometer thick lubricant layer for various applications, and particularly useful for magnetic recording media.

Ultra-low profile multidentate lubricant for use as a sub-nanometer thick lubricant layer for magnetic media

A method and apparatus for determining the wear on a hard disk drive. Specifically, determining the overcoat wear of a head and/or disk during operation. In one embodiment, the magnetic head is disposed adjacent to the disk. A slider voltage is applied between a disk having a first overcoat and a head having a second overcoat as the disk is spinning By monitoring in real time a change in both touchdown power and a change in an interfacial current at a head disk interface, an electrochemical oxidation of the first overcoat can be determined. Additionally, by changing the polarity of the slider voltage, an electrochemical oxidation of the second overcoat can be determined. Finally, by measuring a passivation current produced between the head and the disk, the precise location of a touchdown event can be determined.

Monitoring and controlling the electrochemical wear at the head-disk interface

A method for smoothing a medium includes depositing a magnetic layer onto a base, depositing an overcoat layer onto an outer surface of the magnetic layer, and burnishing an outer surface of the overcoat layer. Further, the method includes at least one of (i) directing a first ion beam comprised of first energetic ions toward the outer surface of the magnetic layer at a first shallow grazing angle and smoothing the outer surface of the magnetic layer via etching engagement between the first ion beam and the outer surface of the magnetic layer; and (ii) directing a second ion beam comprised of second energetic ions toward the outer surface of the overcoat layer at a second shallow grazing angle and smoothing the outer surface of the overcoat layer via etching engagement between the second angled ion beam and the outer surface of the overcoat layer.

Data storage medium surface smoothing method and associated apparatus

A method for polishing a carbon overcoat of a magnetic media that results in a smooth surface free of carbon cluster debris. The method involves forming a magnetic disk having a carbon overcoat formed thereon. The carbon overcoat is then polished in the presence of ozone (O). The heat from the polishing process along with the presence of the ozone, cause any carbon particles removed by the polishing to form COgas so that there is no remaining carbon particle debris on the surface of the disk.

Vapor phase chemical mechanical polishing of magnetic recording disks

A method for producing a magnetic recording medium in one embodiment includes forming a magnetic material layer above a substrate, transferring an uneven pattern to the magnetic material layer to form concave portions and convex portions, the convex portions being magnetic regions, depositing a nonmagnetic material above the concave portions to form nonmagnetic regions, forming an oxide layer and/or hydroxide layer above the magnetic regions of the recording layer, and forming an organic material layer which exhibits a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy above the oxide layer and/or hydroxide layer.

Methods of production for corrosion-resistant bit patterned media (BPM) and discrete track media (DTM)

A head-assisted magnetic recording-shingled magnetic recording (HAMR-SMR) type storage device is described that includes a control module and one or more magnetic recording layers partitioned into zones. The control module is configured to write initial data beginning at an initial logical address of a zone. The initial logical address of the zone corresponds to an initial physical address of the zone. Responsive to receiving a command from a host associated with the HAMR-SMR type storage device to reset the zone and write subsequent data, the control module is further configured to reset the initial logical address of the zone to a subsequent physical address of the zone, and after resetting the initial logical address, write the subsequent data beginning at the initial logical address of the zone.

Intra-zone wear leveling for heat-assisted magnetic recording&#x2014;shingled magnetic recording (HAMR-SMR) type storage devices

A system for preventing the accumulation of excess lubrication in the form of lubricant lines on magnetic media disks for hard disk drives uses a mandrel design that produces negligible surface waves when the disks are dipped in lubricant baths. The mandrel has inverted tear drop shaped supports for the disks. The supports are smaller in overall size than an inner diameter hole formed in the disks and diminish the formation of waves in the lubricant bath.

System, method and apparatus to prevent the formation of lubricant lines on magnetic media

A surface agent includes two end portions and a middle portion disposed between the end portions. The end portions include a terminal section and a midsection. The terminal section includes at least one surface active functional group. The midsection includes at least one perfluoroethyl ether unit. The middle portion includes at least one perfluorobutyl ether unit.

Perfluoropolyether lubricant and systems comprising same

A method of radially positioning a heat assisted magnetic recording (HAMR) head writes data to a first band, wherein a radial position of the HAMR head within each data track is defined by a positional bias and a track location. A determination is made regarding whether a threshold has been reached with respect to the first band. If the write threshold has been reached with respect to the first band, then the positional bias associated with the first band is modified to evenly distribute thermal exposure of data tracks in the first band.

System and method for evenly distributing thermal exposure to disk in heat-assisted magnetic recording (HAMR)

A data storage device and method for enabling dynamic fly height control which is insensitive to off-track motions is described. In some embodiments, a hard disk drive acquires signal data from neighboring overlapping tracks which are unwritten, thermally erased, or AC demagnetized. Side-to-side (off-track) positional errors or oscillations of the read head do not affect the signal which arises solely from the magnetic domains on the disk. Thus, signal variations may only arise from changes in the fly height. In other embodiments, neighboring overlapping data tracks are prewritten with reference data. The width of the neighboring overlapping tracks exceeds any expected side-to-side positional errors of the read head, thus signal variations may only arise from changes in the fly height. For all embodiments, the noise or reference data signal may serve as a reliable dynamic measure of the fly height with no effects arising from off-track motions.

Dynamic fly height control that is insensitive to off-track motion

A system, method, and apparatus for forming a high quality master pattern for patterned media, including features to support servo patterns, is disclosed. Block copolymer self-assembly is used to facilitate the formation of a track pattern with narrower tracks. E-beam lithography forms a chemical contrast pattern of concentric rings, where the spacing of the rings is equal to an integral multiple of the target track pitch. The rings include regions within each servo sector header where the rings are offset radially by a fraction of a track pitch. Self-assembly is performed to form a new ring pattern at the target track pitch on top of the chemical contrast pattern, including the radial offsets in the servo sector headers. When this pattern is transferred to disks via nanoimprinting and etching, it creates tracks separated by nonmagnetic grooves, with the grooves and tracks including the radial offset regions.

System, method and apparatus for master pattern generation, including servo patterns, for ultra-high density discrete track media using E-beam and self-assembly of block copolymer microdomains

Growing community of inventors

Palo Alto, CA, United States of America

Bruno Jean Marchon