International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Philip M Rice

Robert G Biskeborn

Calvin S Lo

Teya Topuria

Bruce Alvin Gurney

Matthew Joseph Carey

Stefan Maat

Eric Edward Fullerton

Thai Le

David Thomas Margulies

Hoa Van Do

Ronald Franklin Marks

Ren Xu

Robin Frederick Charles Farrow

Ho-Cheol Kim

Charles Thomas Rettner

Kumar R Virwani

Angela-Kristina Speidel

Leslie E Krupp

Robert Shelby

An apparatus, according to one embodiment, includes a sensor having an active region, a magnetic shield adjacent the active region, a spacer between the active region and the magnetic shield, a second magnetic shield on an opposite side of the active region as the magnetic shield, and a second spacer between the active region and the second magnetic shield. Both spacers include an electrically conductive ceramic layer. The sensor is an electronic lapping guide.

Tunnel magnetoresistive sensor having conductive ceramic layers

An apparatus according to one embodiment includes a sensor having an active region, a magnetic shield adjacent the active region, a spacer between the active region and the magnetic shield, a second magnetic shield on an opposite side of the active region as the magnetic shield, and a second spacer between the active region and the second magnetic shield. Both spacers include an electrically conductive ceramic layer. The electrically conductive ceramic layer of the spacer has a different composition than the electrically conductive ceramic layer of the second spacer.

An apparatus according to one embodiment includes a sensor having an active region, a magnetic shield adjacent the active region, and a spacer between the active region and the magnetic shield. The spacer includes an electrically conductive ceramic layer. An apparatus according to another embodiment includes a sensor having an active tunnel magnetoresistive region, a magnetic shield adjacent the tunnel magnetoresistive region, and a spacer between the tunnel magnetoresistive region and the magnetic shields. The spacer includes an electrically conductive ceramic layer.

A chromium oxide film is formed at room temperature. The chromium oxide film has at least one partially polycrystalline portion and/or at least one amorphous portion depending upon the substrate(s) over which the chromium oxide film is formed. Partially polycrystalline portion(s) of the chromium oxide film are exposed, at room temperature, to an electron beam that has an accelerating voltage of at least 100 kilovolts to further crystallize the partially polycrystalline portion(s). Amorphous portion(s) of the chromium oxide film are exposed, at room temperature, to an electron beam that has an accelerating voltage of more than 100 kilovolts to crystallize the amorphous portion(s).

Hardening chromium oxide films in a magnetic tape head and other structures

A method for manufacturing an alumina-based layer structure having transition regions between layers is disclosed. The method may include ion milling a stainless steel structure surface to partially reduce a metal oxide layer from, and create an exposed portion of, the surface. The method may include oxidizing the exposed portion of the surface to form a crystallized metal oxide bonding layer, growing a crystallized alumina layer onto the metal oxide bonding layer, and diffusing metal from the surface into the crystallized alumina layer, to form a graded aluminate spinel layer. The method may include forming a first transition region from the graded aluminate spinel layer to a crystalline alumina layer, growing the crystalline alumina layer from the first transition region, forming a second transition region from the crystalline alumina layer to an amorphous alumina layer, and growing the amorphous alumina layer from the second transition region.

Bonded alumina coating for stainless steel

In one general embodiment, an apparatus includes a sensor having an active tunnel magnetoresistive region, magnetic shields flanking the tunnel magnetoresistive region, and spacers between the active tunnel magnetoresistive region and the magnetic shields. The active tunnel magnetoresistive region includes a free layer, a tunnel barrier layer and a reference layer. At least one of the spacers includes an electrically conductive ceramic layer. The presence of the electrically conductive ceramic layer enables current-perpendicular-to-plane operation, while enhancing wear resistance and resistance to deformities of the thin films.

A method of preparing a fiber including electro-spinning onto a substrate polymer solutions from a plurality of jets to form a network of filaments, wherein at least one jet sprays onto the substrate a first chemical mixture including a carbon fiber precursor compound, and at least one other jet sprays onto the substrate a second chemical mixture comprising a sacrificial polymer and a precursor compound of a functional material; and processing the filaments on the substrate, thereby forming an arrangement of carbon fibers having the functional material deposited thereon.

Methods for preparing carbon hybrid materials

An exchange-coupled magnetic structure includes a ferromagnetic layer, a coercive ferrite layer, such as cobalt-ferrite, for biasing the magnetization of the ferromagnetic layer, and an oxide underlayer, such as cobalt-oxide, in proximity to the coercive ferrite layer. The oxide underlayer has a lattice structure of either rock salt or a spinel and exhibits no magnetic moment at room temperature. The underlayer affects the structure of the coercive ferrite layer and therefore its magnetic properties, providing increased coercivity and enhanced thermal stability. As a result, the coercive ferrite layer is thermally stable at much smaller thicknesses than without the underlayer. The exchange-coupled structure is used in spin valve and magnetic tunnel junction magnetoresistive sensors in read heads of magnetic disk drive systems. Because the coercive ferrite layer can be made as thin as 1 nm while remaining thermally stable, the sensor satisfies the narrow gap requirements of high recording density systems.

Stability-enhancing underlayer for exchange-coupled magnetic structures, magnetoresistive sensors, and magnetic disk drive systems

Exchange-coupled magnetoresistive sensor with a coercive ferrite layer and an oxide underlayer having a spinal lattice structure

An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFecomposition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.

Method for making a magnetoresistive sensor having a cobalt-ferrite pinning layer

An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFe composition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.

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Morgan Hill, CA, United States of America

Philip M Rice