Western Digital Technologies, Inc.

Maxtor Corporation

Sigma Technologies International, Inc.

Wd Media, LLC

Shahid Ali Pirzada

Angelo Yializis

B Ramamurthy Acharya

Paul Christopher Dorsey

Hua Yuan

Ian L Sanders

Kenneth E Johnson

Jia-Jay Bill Liu

Wolfgang Decker

Antony Ajan

Michael G Mikhael

Allen J Bourez

Tomoko Seki

Hoan Cong Ho

Zhaoqiang Bai

Fenghua Zong

A heat-assisted magnetic recording (HAMR) medium has a heat-sink layer, a chemically-ordered FePt (or CoPt) alloy magnetic layer and a MgNiO intermediate layer between the heat-sink layer and the magnetic layer. The intermediate layer is a solid substitution crystalline alloy of the form (MgNi)O, where y is less than 10 and greater than or equal to 0.5. The magnetic layer may be formed directly on the MgNiO intermediate layer, in which case the MgNiO intermediate layer functions as both a seed layer and a thermal barrier layer. The HAMR medium may also include an optional layer of crystalline 'pure' MgO directly below or directly above the MgNiO intermediate layer. If the MgO layer is located directly above the MgNiO intermediate layer then the MgNiO intermediate layer functions primarily as a thermal barrier layer. The HAMR medium with the MgNiO intermediate layer provides a substantial improvement in corrosion resistance.

Heat-assisted magnetic recording (HAMR) medium with improved corrosion resistance

A heat-assisted magnetic recording (HAMR) medium has a multilayered or laminated heat-sink structure. The laminated heat-sink structure includes a first heat-sink layer and a RuAl&#x2014;X thermal barrier layer between the medium substrate and the first heat-sink layer. The laminated heat-sink structure may include a second heat-sink layer may between the substrate and the RuAl&#x2014;X thermal barrier layer. In the RuAl&#x2014;X thermal barrier layer, X is selected from C and one or more oxides of Si, Ti, W, Zr and Hf. The HAMR medium with the laminated heat-sink structure reduces the amount of required laser current as compared to a similar HAMR medium with a conventional single heat-sink layer of the same thickness, while also slightly improving magnetic properties and recording performance.

Heat-assisted magnetic recording (HAMR) medium with thermal barrier layer in multilayered heat-sink structure

A recording medium having improved signal-to-noise ratio (SNR) capabilities and head-disk interface characteristics includes an etched smoothened underlayer, over which the recording layer is grown. One mechanism for increasing the SNR is by growing more columnar magnetic grain structures within the recording layer, which is facilitated by a smoother underlayer template.

Smooth structures for heat-assisted magnetic recording media

Magnetic recording media having a protective carbon overcoat adapted to protect the magnetic recording layer from surface contact events and corrosion. The carbon overcoat includes at least two layers. A first layer is adapted to protect the magnetic recording layer from surface contact events and corrosion. The second layer is disposed on the first layer and is adapted to enhance the bonding of a lubricant to the carbon overcoat and to minimize head degradation. The magnetic recording media of the present invention advantageously enables the use of thin carbon overcoats, enhancing areal density, while maintaining good tribological properties.

Magnetic recording medium with multilayer carbon overcoat

Carbon overcoat for magnetic recording medium

A porous metallic layer is incorporated in one of the electrodes of a plasma treatment system. A plasma gas is injected into the electrode at substantially atmospheric pressure and allowed to diffuse through the porous layer, thereby forming a uniform glow-discharge plasma. The film material to be treated is exposed to the plasma created between this electrode and a second electrode covered by a dielectric layer. Because of the micron size of the pores of the porous metal, each pore also produces a hollow cathode effect that facilitates the ionization of the plasma gas. As a result, a steady-state glow-discharge plasma is produced at atmospheric pressure and at power frequencies as low as 60 Hz. According to another aspect of the invention, vapor deposition is carried out in combination with plasma treatment by vaporizing a substance of interest, mixing it with the plasma gas, and diffusing the mixture through the porous electrode. A heater is used to maintain the temperature of the electrode above the condensation temperature of the substance to prevent deposition during diffusion. Thus, plasma treatment and vapor deposition can be carried out on a target substrate at the same time at atmospheric pressure.

Electrode for glow-discharge atmospheric-pressure plasma treatment

A plasma treater incorporates a porous metallic layer in one of the electrodes. The porous layer is selected with pores of average size within one order of magnitude of the mean free path of the plasma gas at atmospheric pressure. The plasma gas is injected into the electrode at substantially atmospheric pressure and allowed to diffuse through the porous layer, thereby forming a uniform glow-discharge plasma. The film material to be treated is exposed to the plasma created between this electrode and a second electrode covered by a dielectric layer. Because of the micron size of the pores of the porous metal, each pore also produces a hollow cathode effect that facilitates the ionization of the plasma gas. As a result, a steady-state glow-discharge plasma is produced at atmospheric pressure and at power frequencies as low as 60 Hz.

Steady-state glow-discharge plasma at atmospheric pressure

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Fremont, CA, United States of America

Shahid Ali Pirzada