Seagate Technology Incorporated

Liwen Tan

Eric Walter Singleton

Jae-Young Yi

Victor Sapozhnikov

Konstantin Nikolaev

Jae Young Yi

Shaun Eric McKinlay

Mohammed Shariat Ullah Patwari

ZhiGuo Ge

Steven Paul Bozeman

Mohammed Sharia Ullah Patwari

Jiansheng Xu

Stacey Christine Wakeham

Antonia Tsoukatos

Zhengqi Lu

Daniel Hassett

Zhiguo Ge

Shaun E Mckinlay

Ann Lynch

A magnetoresistive sensor includes a free layer and a cap over the free layer. The cap includes an upper layer and an insertion layer between the upper layer and the free layer. The insertion layer includes a non-magnetic alloy formed of at least one refractory metal and at least one ferromagnetic metal.

Stack cap with a non-magnetic layer including ferromagnetic elements

A data reader may have a magnetoresistive stack with a magnetically free layer decoupled from a first shield by a cap. The cap can have one or more sub-layers respectively configured with a thickness of 4 nm or less as measured parallel to a longitudinal axis of the magnetoresistive stack on an air bearing surface.

Thin data reader cap

Implementations described and claimed herein include a reader structure, comprising a first reader, including a sensor stack and a top shield structure, the top shield structure comprises a synthetic antiferromagnetic shield (SAF) structure, including a reference layer including at least a layer of NiFe and an impurity additive, an RKKY coupling layer RKKY coupling layer (e.g., Ru layer), and a pinned layer. In another implementation, the RL of the SAF shield structure of a first reader includes at least a layer of amorphous magnetic material. Yet, in another implementation, the SAF shield structure includes an insertion layer of amorphous magnetic material under the SAF shield RL, within the SAF shield RL or between the SAF shield RL and SAF shield Ru.

Magnetoresistive sensor fabrication

A data reader generally capable of sensing data bits may be configured at least with a magnetic stack that has free and fixed magnetization structures atop a magnetic seed layer. A bottom shield may be positioned contactingly adjacent the magnetic stack opposite a top shield with the bottom shield having a fixed pinning magnetization set to a predetermined magnetic orientation.

Method of making a bottom shield stabilized magnetic seed layer

A multi-sensor reader that includes a first sensor that has a first sensor stack, which includes a sensing layer that has a magnetization that changes according to an external magnetic field. The first sensor also includes a first seed layer below the first sensor stack. The multi-sensor reader also includes a second sensor stacked over the first sensor. The second sensor includes a second sensor stack, which includes a sensing layer that has a magnetization that changes according to the external magnetic field. The second sensor also includes a second seed layer below the second sensor stack. A stabilization element is included to maintain a magnetization direction of the second seed layer and to stabilize the second seed layer.

Stabilization of one or more upper sensors in multi-sensor readers

A magnetoresistive (MR) sensor including a synthetic antiferromagnetic (SAF) structure that is magnetically coupled to a side shield element. The SAF structure includes at least one magnetic amorphous layer that is an alloy of a ferromagnetic material and a refractory material. The amorphous magnetic layer may be in contact with a non-magnetic layer and antiferromagnetically coupled to a layer in contact with an opposite surface of the non-magnetic layer.

Magnetoresistive sensor with SAF structure having amorphous alloy layer

A multi-sensor reader that includes a first sensor that has a sensing layer with a magnetization that changes according to an external magnetic field. The first sensor also includes first and second side biasing magnets having a magnetization substantially along a first direction. The first and second side biasing magnets align the magnetization of the sensing layer substantially along the first direction when the sensing layer is not substantially influenced by the external magnetic field. The multi-sensor reader further includes a second sensor that is stacked over the first sensor. The second sensor includes a reference layer that has a magnetization that is set substantially along a second direction. The first sensor further includes at least one sensor-stabilization feature that counteracts an influence of a magnetic field utilized to set the magnetization of the reference layer of the second sensor in the second direction on the magnetization of at least one of the first and second side biasing magnets in the first direction.

Sensor stabilization in a multiple sensor magnetic reproducing device

A magnetic sensor has a bottom shield layer, an upper shield layer, and a sensor stack adjacent the upper shield layer. The sensor includes a seed layer between the bottom shield layer and an antiferromagnetic layer of the sensor stack. The seed layer has a magnetic layer adjacent the sensor stack and a nonmagnetic layer adjacent the bottom shield layer.

Magnetic sensor seed layer with magnetic and nonmagnetic layers

Implementations disclosed herein allow a signal detected by a magnetoresistive (MR) sensor to be improved by providing for one or more alloyed layers that each includes a ferromagnetic material and a refractory material. The alloyed layers are provided adjacent to a shield element or between soft magnetic layers of the sensor stack.

Magnetoresistive sensor

A reader stack, such as for a magnetic storage device, the stack having a top synthetic antiferromagnetic (SAF) layer, a magnetic capping layer adjacent to the top SAF layer, an RKKY coupling layer adjacent to the magnetic capping layer opposite the top SAF layer, and a free layer adjacent to the RKKY coupling layer opposite the magnetic capping layer. Also included is a method for biasing a free layer in a reader stack by providing an exchange coupling between the free layer and a top synthetic antiferromagnetic (SAF) layer using a layer having RKKY coupling property positioned between the free layer and the top SAF layer and a magnetic capping layer between the SAF layer and the layer having RKKY coupling property.

Sensor stack structure with RKKY coupling layer between free layer and capping layer

A multi-sensor reader that includes a first sensor that has a first sensor stack, which includes a sensing layer that has a magnetization that changes according to an external magnetic field. The first sensor also includes a first seed element below the first sensor stack. The multi-sensor reader also includes a second sensor stacked over the first sensor. The second sensor includes a second sensor stack, which includes a sensing layer that has a magnetization that changes according to the external magnetic field. The second sensor also includes a second seed element below the second sensor stack. The second seed element is structurally different from the first seed element and includes a stabilization feature.

An apparatus disclosed herein includes a sensor stack including a first layer and an AFM stabilized bottom shield in proximity to the first layer, wherein the AFM stabilized bottom shield is magnetically coupled to the first layer. The apparatus reduces shield-to-shield spacing. The pinned layer of the bottom shield and a pinned layer of the sensor stack are stabilized using the AFM layer in the bottom shield. In one implementation, the bottom shield is made of the SAF structure, with the top layer of the structure adjacent to a pinned layer in the sensor stack.

Magnetoresistive sensor with AFM-stabilized bottom shield

Implementations disclosed herein provide for a magnetoresistive (MR) sensor including a synthetic antiferromagnetic (SAF) structure that is magnetically coupled to a side shield element. The SAF structure includes at least one magnetic amorphous layer that is an alloy of a ferromagnetic material and a refractory material. The amorphous magnetic layer may be in contact with a non-magnetic layer and antiferromagnetically coupled to a layer in contact with an opposite surface of the non-magnetic layer.

Magnetoresistive sensor with SAF structure having crystalline layer and amorphous layer

A magnetic element capable of reading data may generally be configured at least with a magnetic seed lamination disposed between a data reader stack and a magnetic shield. The magnetic seed lamination may be constructed at least with one magnetic layer coupled to the bottom shield and at least one non-magnetic layer decoupling the data reader stack from the at least one magnetic layer.

Data reader with magnetic seed lamination

Implementations disclosed herein allow a signal detected by a magnetoresistive (MR) sensor to be improved by providing for one or more alloyed layers that each include a ferromagnetic material and a refractory material. The alloyed layers are provided adjacent to a shield element or between soft magnetic layers of the sensor stack.

Growing community of inventors

Eden Prairie, MN, United States of America

Liwen Tan