Western Digital (fremont), Inc.

University of Minnesota

Ut-battelle, Inc.

University of Tennessee Research Foundation

Shihai He

Shaoping Li

Ming Mao

Gerardo Bertero

Qunwen Leng

Yuankai Zheng

Rongfu Xiao

Jian-Ping Wang

Yanfeng Jiang

Daniele Mauri

Steven C Rudy

Haiwen Xi

Yunfei Ding

Ge Yi

Zhihong Zhang

Yingbo Zhang

Miaoyin Wang

Daniel K Lottis

Abhinandan Chougule

Lei Wang

Feng Q Liu

Orlando Rios

Lien-Chang Wang

Chen-jung Chien

Michael P Brady

Christopher L Beaudry

Anup Roy

Craig A Bridges

Zhipeng Li

Edgar Lara-Curzio

Changhe Shang

Haifeng Wang

Jianxin Fang

Lawrence F Allard

Guolun Hao

Roberta A Meisner

Srikanth Ganesan

Ruisheng Liu

A permanent magnet may include a FeNphase constitution. In some examples, the permanent magnet may be formed by a technique that includes straining an iron wire or sheet comprising at least one iron crystal in a direction substantially parallel to a <001> crystal axis of the iron crystal; nitridizing the iron wire or sheet to form a nitridized iron wire or sheet; annealing the nitridized iron wire or sheet to form a FeNphase constitution in at least a portion of the nitridized iron wire or sheet; and pressing the nitridized iron wires and sheets to form bulk permanent magnet.

Iron nitride permanent magnet and technique for forming iron nitride permanent magnet

A permanent magnet may include a FeNphase constitution. In some examples, the permanent magnet may be formed by a technique that includes straining an iron wire or sheet comprising at least one iron crystal in a direction substantially parallel to a &#x3c;001&#x3e; crystal axis of the iron crystal; nitridizing the iron wire or sheet to form a nitridized iron wire or sheet; annealing the nitridized iron wire or sheet to form a FeNphase constitution in at least a portion of the nitridized iron wire or sheet; and pressing the nitridized iron wires and sheets to form bulk permanent magnet.

The disclosure describes techniques for forming nanoparticles including FeNphase. In some examples, the nanoparticles may be formed by first forming nanoparticles including iron, nitrogen, and at least one of carbon or boron. The carbon or boron may be incorporated into the nanoparticles such that the iron, nitrogen, and at least one of carbon or boron are mixed. Alternatively, the at least one of carbon or boron may be coated on a surface of a nanoparticle including iron and nitrogen. The nano particle including iron, nitrogen, and at least one of carbon or boron then may be annealed to form at least one phase domain including at least one of FeN, Fe(NB), Fe(NC), or Fe(NCB).

Iron nitride magnetic material including coated nanoparticles

A magnetic read apparatus includes a read sensor, a shield structure and a side magnetic bias structure. The read sensor includes a free layer having a side and a nonmagnetic spacer layer. The shield structure includes a shield pinning structure and a shield reference structure. The nonmagnetic spacer layer is between the shield reference structure and the free layer. The shield reference structure is between the shield pinning structure and the nonmagnetic spacer layer. The shield pinning structure includes a pinned magnetic moment in a first direction. The shield reference structure includes a shield reference structure magnetic moment weakly coupled with the pinned magnetic moment. The side magnetic bias structure is adjacent to the side of the free layer.

Free layer magnetic reader that may have a reduced shield-to-shield spacing

A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

Method for AFC shields for multiple sensor magnetic transducers and magnetic transducers having multiple sensors and AFC shields

A magnetic read apparatus includes a media-facing surface (MFS), a sensor, a shield structure, a side bias structure, and a shield reference bias structure. The sensor includes a free layer and a nonmagnetic layer. The shield structure includes a shield pinning structure and a shield reference structure between the shield pinning structure and the nonmagnetic layer. The nonmagnetic layer is between the free layer and a shield reference structure. The shield pinning structure includes a pinned moment oriented in a first direction. The shield reference structure includes a reference structure moment weakly coupled with the pinned moment. The side bias structure is adjacent to a side of the free layer and biases the free layer in a first direction parallel to the MFS. The shield reference bias structure is adjacent to the shield reference structure and biases the shield reference structure in a direction opposite to the first direction.

Free layer only magnetic reader that may have a reduced shield-to-shield spacing and a multilayer side bias

Apparatuses and methods for providing thin shields in a multiple sensor array are provided. One such apparatus is a magnetic read transducer including a first read sensor, a second read sensor, and a shield assembly positioned between the first read sensor and the second read sensor at an air bearing surface (ABS) of the magnetic read transducer, the shield assembly including a first shield layer assembly having a first footprint with a first area, and a second shield layer assembly having a second footprint with a second area, where the second area is greater than the first area.

Apparatuses and methods for providing thin shields in a multiple sensor array

A magnetic read apparatus includes a first sensor, a shield layer, an insulating layer, a shield structure and a second sensor. The shield layer is between the first sensor and the insulating layer. The shield structure is in the down track direction from the insulating layer. The shield structure includes a magnetic seed structure, a shield pinning structure and a shield reference structure. The magnetic seed structure adjoins the shield pinning structure. The shield pinning structure is between the shield reference structure and the magnetic seed structure. The second sensor includes a free layer and a nonmagnetic spacer layer between the shield reference structure and the free layer. The shield reference structure is between the shield pinning structure and the nonmagnetic spacer layer. The shield pinning structure includes a pinned magnetic moment. The shield reference structure includes another magnetic moment weakly coupled with the pinned magnetic moment.

Magnetic read apparatus having multiple read sensors with reduced sensor spacing usable in two-dimensional magnetic recording applications

A magnetic read apparatus has a media-facing surface (MFS) and includes a read sensor, a magnetic bias structure and an insulating layer. The read sensor has a side, a front occupying part of the MFS and a back. The read sensor includes a free layer, a pinned layer and a barrier layer between the free and pinned layers. The barrier layer has a barrier layer coefficient of thermal expansion. The magnetic bias structure is adjacent to the side of the free layer. The insulating layer includes first and second portions. The first portion of the insulating layer is between the read sensor side and the magnetic bias structure. The second portion of the insulating layer adjoins the read sensor back. The insulating layer has an insulating layer coefficient of thermal expansion that is at least &#x2153; of and not more than 5/3 of the barrier layer coefficient of thermal expansion.

Read sensor having an insulating layer capable of use in two-dimensional magnetic recording

A spin transfer torque magnetic junction includes a magnetic reference layer structure with magnetic anisotropy perpendicular to a substrate plane. A laminated magnetic free layer comprises at least three sublayers (e.g. sub-layers of CoFeB, CoPt, FePt, or CoPd) having magnetic anisotropy perpendicular to the substrate plane. Each such sublayer is separated from an adjacent one by a dusting layer (e.g. tantalum). An insulative barrier layer (e.g. MgO) is disposed between the laminated free layer and the magnetic reference layer structure. The spin transfer torque magnetic junction includes conductive base and top electrodes, and a current polarizing structure that has magnetic anisotropy parallel to the substrate plane. In certain embodiments, the current polarizing structure may also include a non-magnetic spacer layer (e.g. MgO, copper, etc).

Spin transfer torque tunneling magnetoresistive device having a laminated free layer with perpendicular magnetic anisotropy

System and method for magnetic transducers having multiple sensors and AFC shields

A spin transfer torque magnetic junction includes a magnetic reference layer structure with magnetic anisotropy perpendicular to a substrate plane. A laminated magnetic free layer comprises at least three sublayers (e.g. sub-layers of 6 to 30 Angstroms of CoFeB, CoPt, FePt, or CoPd) having magnetic anisotropy perpendicular to the substrate plane. Each such sublayer is separated from an adjacent one by a tantalum dusting layer. An insulative barrier layer (e.g. MgO) is disposed between the laminated free layer and the magnetic reference layer structure. The spin transfer torque magnetic junction includes conductive base and top electrodes, and a current polarizing structure that has magnetic anisotropy parallel to the substrate plane. In certain embodiments, the current polarizing structure may also include a non-magnetic spacer layer (e.g. MgO, copper, etc).

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Fremont, CA, United States of America

Shihai He