Seagate Technology Incorporated

Wd Media, LLC

Headway Technologies, Incorporated

Western Digital (fremont), Inc.

Bogdan Florin Valcu

Kaizhong Gao

Bin Lu

Xiaoding Ma

B Ramamurthy Acharya

Antony Ajan

Hua Yuan

Alexander S Chernyshov

Li Tang

Dieter Klaus Weller

Yue Liu

Thomas P Nolan

Yingguo Peng

Erol Girt

Paul Christopher Dorsey

Yukiko A Kubota

Andreas Moser

Connie C Liu

Weihao Xu

Tobias Maletzky

Michael Alex

David E Wachenschwanz

Tao Zhang

Thomas Francis Ambrose

Abebe Hailu

Kai-Chieh Chang

Alexander Yulievich Dobin

Wen Jiang

Alain Truong

Shanghsien S Rou

The present embodiments relate to a thermally-assisted magnetic recording (TAMR) head. A magnetic assist current can be applied to the TAMR head to assist in reducing timing jitter as the TAMR head interacts with a magnetic recording material. The TAMR head can include a main write pole including a tip portion and configured to direct a magnetic field for interacting with a magnetic recording medium. The TAMR head can include a laser diode to heat the magnetic recording medium and a dynamic fly height (DFH) heating element for dynamically controlling a height of the main write pole. The heating element can be of a parallel bias circuit that directs a direct current (DC) bias current flow along an electrical path from the magnetic yoke element to the tip portion of the main write pole adjacent to an air bearing surface (ABS).

Thermally-assisted magnetic recording (TAMR) head with magnetic assist current

Methods and media structures are provided for increasing writability and reducing unintentional erasure of perpendicular magnetic recording media. Variable permeability is controlled within a thin soft underlayer (SUL) structure, independent of bulk SUL material properties such as magnetic moment (B) and magnetic anisotropy (Hk). Media with an improved combination of easier writability on the recorded track and difficult erasure off-track (between tracks and on neighboring tracks) is achieved, in part, by an unbalanced antiferromagnetically coupled (AFC) SUL structure. A permeability gradient is established within the soft underlayer with layers having different values of permeability and magnetic thickness (Bt). In an aspect, a first SUL layer includes a high permeability region and an overlying low permeability region. A second layer antiferromagnetically couples the first layer to a low permeability third SUL layer. The present invention may be utilized with high density perpendicular recording media requiring carefully balanced magnetic properties.

Antiferromagnetic coupling layers

A perpendicular magnetic recording layer of a magnetic recording medium includes a plurality of bit-patterned magnetic islands, wherein each of the plurality of islands overlay a soft magnetic under-layer. Each of the magnetic islands includes a first magnetic sub-layer adjacent a second magnetic sub-layer, wherein the first sub-layer has a relatively high magnetic anisotropy that is greater than a magnetic anisotropy of the second sub-layer. The magnetic recording layer further includes a third sub-layer, which extends to connect each of the plurality of islands. The third sub-layer may have a magnetic anisotropy that is less than that of the second sub-layer of each of the magnetic islands and/or may serve as an interlayer, extending between the first sub-layer and the soft magnetic under-layer of the recording medium, and having a structure to help to produce the greater anisotropy first magnetic sub-layer.

Magnetic layering for bit-patterned stack

Aspects include recording media with enhanced areal density through reduction of head media spacing, head keeper spacing, or head to soft underlayer spacing. Such aspects comprise replacing currently non-magnetic components of devices, such as interlayers and overcoats with components and compositions comprising magnetic materials. Other aspects relate to magnetic seed layers deposited within a recording medium. Preferably, these aspects, embodied as methods, systems and/or components thereof reduce effective magnetic spacing without sacrificing physical spacing.

Reduced spacing recording apparatus

The present disclosure generally relates to a HAMR head and techniques and apparatus for HAMR writer pole length characterization. One or more bits may be magnetically written on a disk using a leading edge of the writer pole at a first polarity. The disk may be moved under a body of the writer pole to magnetically write the one or more bits in the disk at a second polarity that is opposite to the first polarity to generate a feedback pulse having a signal amplitude. The signal amplitude of the feedback pulse may be measured as a function of writing frequency. A first effective length of the writer pole may be determined based on the measurements.

HAMR writer pole length characterization

Systems and methods for providing heat assisted magnetic recording (HAMR) media configured to couple energy from a near field transducer (NFT) are provided. One such method includes providing a magnetic recording layer including an L10 ordered FePt or an L10 ordered CoPt, selecting a plurality of preselected parameters for a coupling layer, the preselected parameters including a material, a preselected deposition temperature, and a preselected thickness, and depositing the coupling layer directly on the magnetic recording layer using the preselected parameters such that the coupling layer has an extinction coefficient greater than 0.1.

Systems and methods for providing heat assisted magnetic recording media configured to couple energy from a near field transducer

An energy assisted magnetic recording (EAMR) system includes a magnetic recording medium including a plurality of bi-layers and a magnetic recording layer on the plurality of bi-layers, a magnetic transducer configured to write information to the magnetic recording medium, and a light source positioned proximate the magnetic transducer and configured to heat the magnetic recording medium. Each of the plurality of bi-layers includes a heatsink layer and an amorphous under-layer on the heatsink layer.

Recording media with multiple bi-layers of heatsink layer and amorphous layer for energy assisted magnetic recording system and methods for fabricating the same

An apparatus may include a composite soft underlayer and a perpendicular magnetic recording layer overlying the composite soft underlayer. The composite soft underlayer may include a growth template layer, a negative magnetic anisotropy layer overlying the growth template layer, and a magnetically soft layer overlying the negative magnetic anisotropy layer. In some embodiments, the negative magnetic anisotropy layer includes a plurality of grains, and substantially all the grains have negative magnetic anisotropy along an axis substantially perpendicular to a major plane of the composite soft underlayer. In some embodiments, the negative magnetic anisotropy layer includes a thickness of less than or equal to about 3 nm.

Composite soft underlayer including negative anisotropy material

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Fremont, CA, United States of America

Bogdan Florin Valcu