213 results about "Magnetosphere" patented technology

A method for maximizing the interfacial properties of magnetoresistive sensors, such as spin valve and GMR sensors used in storage devices, comprises selecting the materials for ferromagnetic layers and for electrically conductive spacers that are interposed between the ferromagnetic layers. The electronegativities of the selected materials are substantially matched so that an absolute value of the differences in electronegativities is minimized. The conductive spacer material provides a relatively low resistivity and a large mean free path. The sensors experience greater chemical and thermal stability, are corrosion resistant, and realize an increased signal output.

A magnetic memory is described. In one aspect, the magnetic memory includes magnetic junctions and at least one semi-spin valve (SSV) line adjacent to the magnetic junctions. Each magnetic junction includes a magnetic free layer. The SSV line(s) include a ferromagnetic layer and a nonmagnetic layer between the ferromagnetic layer and the magnetic junctions. The SSV line(s) are configured to exert a spin accumulation induced torque on at least a portion of the magnetic junctions due to an accumulation of spin polarized current carriers from a current that is substantially in-plane. The free layer is configured to be written using at least the spin accumulation induced torque. In another aspect, the magnetic memory includes magnetic memory cells and at least one spin torque (ST) line that is analogous to the SSV line. Each magnetic memory cell includes magnetic junction(s) analogous to those above and magnetoelectric selection device(s).

The present invention to provide a new technique to reduce a variation in switching field of a magnetization free layer in a magnetic memory. The magnetic memory according to the present invention includes a magnetization free layer including a ferromagnetic layer having a shape magnetic anisotropy in a first direction and a magnetic strain constant is positive; and a stress inducing structure configured to apply a tensile stress to said magnetization free layer in a same direction as the first direction.

A perpendicular magnetic recording disk having a single domain exchange-coupled laminated soft magnetic underlayer (SUL) is disclosed. The SUL is a combination synthetic anti-parallel coupled SUL structure, which has the product (Mst) of saturation magnetization and film thickness of the middle ferromagnetic layer less than the sum of the Mst of the bottom and top ferromagnetic layers. Subjected to a post radial field reset process, this SUL provides single domain state. Moreover, both robustness of stray fields and low permeability are obtained while keeping excellent corrosion resistance and cost effective manufacturability.

A magnetic cell comprises: a first ferromagnetic layer whose magnetization is substantially fixed in a first direction; a second ferromagnetic layer whose magnetization is substantially fixed in a second direction opposite to the first direction; a third ferromagnetic layer provided between the first and the second ferromagnetic layers, a direction of magnetization of the third ferromagnetic layer being variable; a first intermediate layer provided between the first and the third ferromagnetic layers; and a second intermediate layer provided between the second and the third ferromagnetic layers. The direction of magnetization of the third ferromagnetic layer can be determined under an influence of spin-polarized electrons upon the third ferromagnetic layer by passing a current between the first and the second ferromagnetic layers.

A system for controlling the direction of magnetization of materials comprising a ferromagnetic device with first and second ferromagnetic layers. The ferromagnetic layers are disposed such that they combine to form an interlayer with exchange coupling. An insulating layer and a spacer layer are located between the first and second ferromagnetic layers. A direct bias voltage is applied to the interlayer exchange coupling, causing the direction of magnetization of the second ferromagnetic layer to change. This change of magnetization direction occurs in the absence of any applied external magnetic field.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The free layer includes a first ferromagnetic layer and a second ferromagnetic layer. The second ferromagnetic layer has a very high perpendicular anisotropy and an out-of-plane demagnetization energy. The very high perpendicular anisotropy energy is greater than the out-of-plane demagnetization energy of the second layer.

A magneto-resistive element comprising a free layer having two ferromagnetic layers having a nonmagnetic layer interposed therebetween are coupled with each other in an anti-ferromagnetic manner, a difference between an absolute value of a total of magnetizations of at least one ferromagnetic layer in which the magnetization direction is a first direction and an absolute value of a total of magnetizations of at least one ferromagnetic layer in which the magnetization direction is a second direction which is opposite to the first direction is equal to or smaller than 5×10⁻¹⁵ emu, and planes parallel to a substrate of the ferromagnetic layers are smaller as the planes are distant from the substrate.

A current-perpendicular-to-the-plane magnetoresistive sensor structure includes at least an improved top shield structure and optionally also a similar bottom shield structure. The top shield structure includes an antiparallel structure (APS) of two ferromagnetic films and a nonmagnetic antiparallel coupling (APC) film between them. The APC film induces antiferromagnetic (AF) coupling between the two ferromagnetic films so that they have their respective magnetizations oriented antiparallel. An important aspect of the APS is that there is no antiferromagnetic layer adjacent the upper ferromagnetic film, so that the upper ferromagnetic film does not have its magnetization pinned by an antiferromagnetic layer. An electroplated shield layer is formed above the APS. A nonmagnetic decoupling layer is located between the APS and the electroplated shield layer to prevent domain wall movement in the electroplated shield from transferring to the ferromagnetic layers in the APS and thus possibly induce noise in the sensor.

A two-dimensional magnetic recording (TDMR) read head structure has the lower read sensor free layer magnetization biased by side shields of soft magnetic material. A center shield between the lower and upper sensors is an antiparallel coupled magnetic structure, i.e., first and second ferromagnetic layers separated by an antiparallel coupling (APC) layer. The first ferromagnetic layer is ferromagnetically exchange coupled to the side shields of the lower sensor to stabilize the magnetization of the lower sensor's free layer. The first ferromagnetic layer of the center shield is a multilayer of a lower NiFe layer and an upper CoFeB alloy layer inserted below the APC layer. The CoFeB alloy insertion layer increases the antiparallel coupling of the first and second ferromagnetic layers of the center shield after two orthogonal anneals so that the magnetization of the first ferromagnetic layer is aligned parallel to the air-bearing surface (ABS) of the TDMR structure.

A magnetic recording system is provided having a write head employing a combination of magnetic write field gradient and thermal gradient to write data on a ‘thermal spring’ magnetic recording media. The write head comprises a magnetic element using a write current to induce a magnetic write field at the magnetic media and a thermal element using a very small aperture laser to heat a portion of the media. The thermal spring magnetic media comprises [comprises] first and second stacks providing two exchange coupled ferromagnetic layers having different Curie temperatures [The first stack has a high magneto-crystalline anisotropy, a relatively low saturation magnetization and a low Curie temperature.] [The second stack has a relatively low magneto-crystalline anisotropy, a high saturation magnetization and a high Curie temperature.] The magnetic field gradient and the thermal gradient are arranged to substantially overlap at the trailing edge of the heated portion of the magnetic media allowing data at high density with high thermal stability to be recorded on the rapidly cooling thermal spring magnetic recording media.

A device for discovering, identification and monitoring, of mechanical flaws in metallic structures is disclosed, based on magneto-graphic/magnetic tomography technique to identify stress-related defects. The device can determine the position of the defect or stress including depth information. The device includes registration means that optimized for use with metallic structures of various types, shapes, and sizes. Applications include a real-time quality control, monitoring and emergency alarms, as well structural repairs and maintenance work recommendations and planning. Examples of the device implementation include pipes for oil and gas industry monitoring, detection of flaws in roiled products in metallurgical industry, welding quality of heavy duty equipment such as ships, reservoirs, bridges, etc. It is especially important for loaded constructions, such as pressured pipes, infrastructure maintenance, nuclear power plant monitoring, bridges, corrosion prevention and environment protection.

Nano-oxide based current-perpendicular-to-plane (CPP) magnetoresistive (MR) sensor stacks are provided, together with methods for forming such stacks. Such stacks have increased resistance and enhanced magnetoresistive properties relative to CPP stacks made entirely of metallic layers. Said enhanced properties are provided by the insertion of magnetic nano-oxide layers between ferromagnetic layers and non-magnetic spacer layers, whereby said nano-oxide layers increase resistance and exhibit spin filtering properties. CPP sensor stacks of various types are provided, all having nano-oxide layers formed therein, including the spin-valve type and the synthetic antiferromagnetic pinned layer spin-valve type. Said stacks can also be formed upon each other to provide laminated stacks of different types.

Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The manufacturing method uses two linear mask patterns intersecting with each other to form sharp corners of a ferromagnetic tunnel junction. An electron beam (EB) drawing may be used to form the S-shape plane. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.