Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Hong Deng

Robert Waltman

Xing-Cai Guo

Bruno Jean Marchon

Kai Tang

Yoshihiro Ikeda

Kentaro Takano

John Martin Burns

Daryl J Pocker

Mary Frances Minardi

Vedantham Raman

Richard Longstreth White

Bala Krishna Pathem

George William Tyndall, Iii

Jinliu Wang

Yu-Chen Wu

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 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 surface agent includes two end portions and a middle portion disposed between the end portions. The end portions include an anchor group or a truncation group. The anchor group includes at least one surface active functional group. The midsection includes at least one perfluoroalkyl-branched perfluorinated ether unit.

Perfluorinated polyethers (PFPE) as magnetic lubricants

The invention uses an adhesion layer of an amorphous alloy of aluminum. A first aluminum titanium embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/&#x2212;5 at. %). A second embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/&#x2212;5 at. %) and up to 10 at. % Zr with 5 at. % Zr being preferred. A third embodiment is aluminum tantalum preferably including from 15 to 25 at. % tantalum with 20 at. % being preferred. The most preferred compositions are AlTi, AlTiZror AlTa. The adhesion layer is deposited onto the substrate. The substrate can be glass or a metal such as NiP-plated AlMg. The preferred embodiment of media according to the invention is for perpendicular recording and includes a magnetically soft underlayer deposited above the adhesion layer.

Adhesion layer for thin film magnetic recording medium

A lubricant composition is provided comprising a first liquid lubricant and a second liquid lubricant, wherein the first liquid lubricant contains a cyclotriphosphazene ring attached to at least one perfluoropolyether having a single terminal hydroxyl group, and the second liquid lubricant contains a perfluoropolyether having two end groups selected from hydroxyl, tertiary amine, and combinations thereof. A magnetic recording media is also provided, comprising a substrate, a magnetic layer, an overcoat layer and a lubricant layer thereon, wherein the lubricant layer is formed from the lubricant composition. A further aspect of the invention concerns a method of making a magnetic recording media comprising forming a magnetic layer on a substrate; forming a protective overcoat layer on the magnetic layer; and forming a lubricant layer on the surface of the overcoat layer by applying the lubricant composition to the surface of the overcoat layer. The lubricant composition is useful for magnetic recording media, especially for magnetic storage hard disk drives, and provides improvements such as substantially reduced lubricant thickness variations when applied to a surface of a hard disk drive.

Lubricant composition for magnetic recording media

A thin film structure comprising a protective layer structure having at least two different compositions of carbon and nitrogen with the surface of the protective layer having the lowest nitrogen content is disclosed. The protective layer structure of the invention is preferably used over the magnetic material in a thin film magnetic disk. In the protective layer structure of the invention, the durability of a relatively high nitrogen content CNx material is improved by the addition of a surface sublayer of CNx with a relatively low nitrogen concentration. The resulting protective layer structure provides superior durability to either of the thin film compositions used alone achieving a synergistic result. The protective layer structure of the invention has the additional benefit of decreasing the polar surface energy and therefore, improving the corrosion resistance of the film structure. In one embodiment the protective layer of the invention is implemented as two discrete sublayers with the surface sublayer having the lowest nitrogen concentration. In this embodiment the surface sublayer has from 0 to 8 at. % nitrogen and the higher nitrogen content is between 10 and 25 at. % nitrogen at the magnetic layer interface. The protective layer structure of the invention can also be implemented as a film in which the nitrogen content gradually decreases between the magnetic layer and the surface of the protective layer structure.

Magnetic thin film media with a protective layer of CNx having a plurality of compositions

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San Jose, CA, United States of America

Hong Deng