1600results about "Nanomagnetism" patented technology

A method and system for providing a magnetic element capable of being written using spin-transfer effect while being thermally stable and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first, second and third pinned layers, first and second nonmagnetic layers, a free layer and a nonmagnetic spacer layers. The first, second and third pinned layers are ferromagnetic and have first, second and third magnetizations pinned in first, second and third directions. The first and second nonmagnetic layers include first and second diffusion barriers, respectively. The first and second nonmagnetic layers are between the first and second pinned layers and the second and third pinned layers, respectively. The first and second pinned layers and the second and third pinned layers are antiferromagnetically coupled. The nonmagnetic spacer layer is conductive and resides between the free layer and the third pinned layer. In addition, performance can be further improved by doping Co containing ferromagnetic layers with Cr and/or Pt.

An assembly with a substrate, nanomagnetic material and magetoresistive material. The nanomagnetic material has a saturation magentization of from about 2 to about 3000 electromagnetic units per cubic centimeter; and it contains nanomagnetic particles with an average particle size of less than about 100 nanometers. The average coherence length between adjacent nanomagnetic particles is less than 100 nanometers.

A ferromagnetic thin-film based digital memory cell with a memory film of an anisotropic ferromagnetic material and with a source layer positioned on one side thereof so that a majority of conduction electrons passing therefrom have a selected spin orientation to be capable of reorienting the magnetization of the film. A disruption layer is positioned on the other side of the memory film so that conduction electrons spins passing therefrom are substantially random in orientation. The magnitude of currents needed to operate the cell can be reduced using coincident thermal pulses to raise the cell temperature.

A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0≧Ms<√{square root over ( )}{Jw/(6nAt)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.

The present invention provides a tunneling magneto-resistive read sensor structure that improves sensitivity and linear density of the sensor structure. The sensor includes first and second electrodes and a stack positioned between the electrodes. The stack includes first and second free layers with magnetization orientations that are biased relative to each other. A tunneling barrier (insulating layer) or non-magnetic metal spacer is positioned between the first and second free layers. A sense current is passed between the first and second free layers of the stack. The amount of current passing through the first and second free layer changes based upon the orientation of the first and second free layers relative to each other.

A spin-torque transfer memory random access memory (STTMRAM) element includes a fixed layer formed on top of a substrate and a a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer and made of an iron platinum alloy with at least one of X or Y material, X being from a group consisting of: boron (B), phosphorous (P), carbon (C), and nitride (N) and Y being from a group consisting of: tantalum (Ta), titanium (Ti), niobium (Nb), zirconium (Zr), tungsten (W), silicon (Si), copper (Cu), silver (Ag), aluminum (Al), chromium (Cr), tin (Sn), lead (Pb), antimony (Sb), hafnium (Hf) and bismuth (Bi), molybdenum (Mo) or rhodium (Ru), the magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate.

A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.

A method and system for providing energy assisted magnetic recording (EAMR) heads including EAMR transducers are described. The method and system include aligning a laser bar to the EAMR heads on a substrate. The laser bar includes lasers in locations corresponding to a portion of the EAMR transducers. The method and system also include bonding the laser bar to the substrate and removing a portion of the laser bar to separate the plurality of lasers. The substrate is separated into the EAMR heads.

A method and system for providing a magnetoresistive sensor is disclosed. The method and system include providing a first pinned layer, providing a free layer having a length, and providing a first spacer layer disposed between the first pinned layer and the free layer. The first spacer layer has a first interface with the first pinned layer. The method and system also include providing a second pinned layer and providing a second spacer layer disposed between the free layer and the second pinned layer. The second spacer layer has a second interface with the second pinned layer. A direction of a current passed through the magnetoresistive sensor is through the first interface, through the second interface, and along at least a portion of the length of the free layer.

The invention provides a water soluble complex comprising an inner core of a metal or semi-conductor nanoparticle. The nanoparticle is coated with a hydrophobic ligand, which is encapsulated in a micelle. In an aqueous medium, the micelle comprises a hydrophilic shell and a hydrophobic core, the hydrophilic shell comprising a plurality of hydrophilic moieties, the hydrophobic core comprising a plurality of hydrophobic moieties, each hydrophobic moiety comprising at least one chain, each chain comprising a minimum of 8 atoms; wherein the total number of atoms in all chains for each moiety comprises at least 24 atoms. The micelle has a minimum average diameter of approximately 5 nm and a maximum average diameter of approximately 45 nm.

A method and system for providing a magnetic element are disclosed. The method and system include providing first and second pinned layers, a free layer, and first and second barrier layers between the first and second pinned layers, respectively, and the free layer. The first barrier layer is preferably crystalline MgO, which is insulating, and configured to allow tunneling through the first barrier layer. Furthermore, the first barrier layer has an interface with another layer, such as the free layer or the first pinned layer. The interface has a structure that provides a high spin polarization of at least fifty percent and preferably over eighty percent. The second barrier layer is insulating and configured to allow tunneling through the second barrier layer. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.

A magnetic disk including a substrate, a recording track section which is made of a magnetic member for recording and reproducing information magnetically and is provided on the substrate, and a guard band member which is provided between the recording track sections adjacent to each other so that they are substantially continued in a track direction and is harder than the magnetic member and is made of a non-magnetic material. Moreover, the magnetic member is not provided or magnetic members with a different thickness from the magnetic member forming the recording track section is provided on a lower area of the guard band member.

The present invention provides an improved top spin valve and method of fabrication. In the preferred embodiment of the top spin valve of the present invention, a seed layer is formed of non-magnetic material having the elements Ni and Cr. In the preferred embodiments, the seed layer material has an ion milling rate comparable to that of the free layer material. This allows free layer sidewalls to be formed with shorter tails, improving free layer-to-magnetic bias layer junction, thus improving free layer domain structure and track width. In one embodiment, the seed layer may have NiFeCr, with Cr from about 20% to 50%. In another embodiment, the seed layer may have NiCr, with about 40%. Some embodiments may have the seed layer formed on an optional Ta pre-seed layer. Such embodiments provide an improved fcc (111) texture particularly for NiFe and for NiFe/CoFe free layers grown on a seed layer improving spin valve performance, and especially in embodiments having very thin NiFe free layers, ultra thin NiFe free layers, and free layers without NiFe, such as a free layer of CoFe. Such a seed layer can improve AFM pinning layer texture to improve the exchange bias, thus providing better thermal stability. Such a seed layer also provides high resistivity and can improve the magnetostriction of adjacent NiFe free layer material or improve the soft properties of an adjacent CoFe free layer.

We describe the structure and method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co₆₀Fe₂₀B₂₀. of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.

An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E-6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.

A highly sensitive assay is disclosed which combines immunomagnetic enrichment with multiparameter flow cytometric and immunocytochemical analysis to detect, enumerate and characterize carcinoma cells in the blood. The assay can detect one epithelial cell or less in 1 ml of blood and has a greater sensitivity than conventional PCR or immunohistochemistry by 1-2 orders of magnitude. In addition, the assay facilitates the biological characterization and staging of carcinoma cells.

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 method and system for providing a magnetic element is disclosed. The method and system include providing a ferromagnetic pinned layer, providing a free layer, and providing a spacer layer between the pinned layer and the free layer. The pinned layer and free layer are ferromagnetic and have a pinned layer magnetization and a free layer magnetization, respectively. The spacer layer is nonmagnetic. In one aspect, the free layer is configured to have an increased magnetic damping constant. In another aspect, the method and system also include providing a second pinned layer and a second spacer layer between the free layer and the second pinned layer. In this aspect, the first pinned layer and/or the second pinned layer are configured such that a forward torque and a reflected torque due to a current driven through the magnetic element in a current-perpendicular-to-plane configuration are substantially equal and opposite.

A method and system for providing a magnetic element is disclosed. The method and system include providing a pinned layer, a magnetic current confined layer, and a free layer. The pinned layer is ferromagnetic and has a first pinned layer magnetization. The magnetic current confined layer has at least one channel in an insulating matrix and resides between the pinned layer and the free layer. The channel(s) are ferromagnetic, conductive, and extend through the insulating matrix between the free layer and the pinned layer. The size(s) of the channel(s) are sufficiently small that charge carriers can give rise to ballistic magnetoresistance in the magnetic current confined layer. The free layer is ferromagnetic and has a free layer magnetization. Preferably, the method and system also include providing a second pinned layer and a nonmagnetic spacer layer between the second pinned layer and the free layer. In this aspect, the magnetic element is configured to allow the free layer magnetization to be switched using spin transfer.

A method and system for providing a magnetic element and a magnetic memory utilizing the magnetic element are described. The magnetic element is used in a magnetic device that includes a contact electrically coupled to the magnetic element. The method and system include providing pinned, nonmagnetic spacer, and free layers. The free layer has an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is less than the out-of-plane demagnetization energy. The nonmagnetic spacer layer is between the pinned and free layers. The method and system also include providing a perpendicular capping layer adjoining the free layer and the contact. The perpendicular capping layer induces at least part of the perpendicular magnetic anisotropy in the free layer. The magnetic element is configured to allow the free layer to be switched between magnetic states when a write current is passed through the magnetic element.

An integrated circuit can have a first substrate supporting a magnetic field sensing element and a second substrate supporting another magnetic field sensing element. The first and second substrates can be arranged in a variety of configurations. Another integrated circuit can have a first magnetic field sensing element and second different magnetic field sensing element disposed on surfaces thereof.

A long range, periodically ordered array of discrete nano-features (10), such as nano-islands, nano-particles, nano-wires, non-tubes, nano-pores, nano-composition-variations, and nano-device-components, are fabricated by propagation of a self-assembling array or nucleation and growth of periodically aligned nano-features. The propagation may be induced by a laterally or circularly moving heat source, a stationary heat source arranged at an edge of the material to be patterned (12), or a series of sequentially activated heaters or electrodes. Advantageously, the long-range periodic array of nano-features (10) may be utilized as a nano-mask or nano-implant master pattern for nano-fabrication of other nano-structures. In addition, the inventive long-range, periodically ordered arrays of nano-features are useful in a variety of nanoscale applications such as addressable memories or logic devices, ultra-high-density magnetic recording media, magnetic sensors, photonic devices, quantum computing devices, quantum luminescent devices, and efficient catalytic devices.

A single crystalline ternary nanostructure having the formula A_xB_yO_z, wherein x ranges from 0.25 to 24, and y ranges from 1.5 to 40, and wherein A and B are independently selected from the group consisting of Ag, Al, As, Au, B, Ba, Br, Ca, Cd, Ce, Cl, Cm, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Gd, Ge, Hf, Ho, I, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Tc, Te, Ti, Ti, Tm, U, V, W, Y, Yb, and Zn, wherein the nanostructure is at least 95% free of defects and/or dislocations.

A method for forming a hard bias structure in a magnetoresistive sensor is disclosed. A magnetoresistive sensor having a soft magnetic bias layer, spacer layer, and a magnetoresistive layer, is formed over a substrate having a gap layer. A mask is formed over a portion of the magnetoresistive sensor structure to define a central region. The masked structure is ion milled to remove portions not shielded by the mask, to form the central region with sloped sides, and to expose a region of the gap layer laterally adjacent the sloped sides. A first underlayer is deposited onto at least the sloped sides at a high deposition angle. A second underlayer is deposited to at least partially overlap the first underlayer, and at a first lower deposition angle. A hard bias layer is deposited over at least a portion of the second underlayer, and at a second lower deposition angle.

Methods of fabricating MTJ arrays using two orthogonal line patterning steps are described. Embodiments are described that use a self-aligned double patterning method for one or both orthogonal line patterning steps to achieve dense arrays of MTJs with feature dimensions one half of the minimum photo lithography feature size (F). In one set of embodiments, the materials and thicknesses of the stack of layers that provide the masking function are selected so that after the initial set of mask pads have been patterned, a sequence of etching steps progressively transfers the mask pad shape through the multiple mask layer and down through all of the MTJ cell layers to the form the complete MTJ pillars. In another set of embodiments, the MTJ/BE stack is patterned into parallel lines before the top electrode layer is deposited.

A magnetic memory cell having a ferromagnetic free layer and a ferromagnetic pinned reference layer, each having an out-of-plane magnetic anisotropy and an out-of-plane magnetization orientation and switchable by spin torque. The cell includes a ferromagnetic assist layer proximate the free layer, the assist layer having a low magnetic anisotropy less than about 500 Oe. The assist layer may have in-plane or out-of-plane anisotropy.

A method and system for providing a magnetoresistive structure is disclosed. The magnetoresistive structure includes a pinned layer, a nonmagnetic spacer layer, a free layer, a filter layer, a specular layer, a barrier layer, and a capping layer. The nonmagnetic spacer layer resides between the pinned layer and the free layer. The free layer is electrically conductive and resides between the filter layer and the nonmagnetic spacer layer. The specular layer includes a first material and is electrically insulating. The barrier layer resides between the specular oxide layer and the capping layer. The barrier layer is nonmagnetic and includes a second material different material from the first material. The capping layer includes a third material different from the second material.

A magnetoresistive read head includes a magnetoresistive sensor and a bias structure adjacent to the magnetoresistive sensor. The bias structure provides a magnetostatic bias field for the magnetoresistive sensor. The bias structure includes an underlayer, a bias layer over the underlayer, and at least one dusting layer directly below at least one of the underlayer or the bias layer.

A technique for reducing pole tip protrusion (“PTP”) in a magnetic write head and giant magnetoresistive (“GMR”) stripe temperature in an associated read head structure utilizing one or more internal diffuser regions. In a representative embodiment disclosed, this may be effectuated through the appropriate placement of a relatively highly conductive material diffuser region (e.g. gold (Au) or copper (Cu)) above the poles, between the first pole and the coil and/or through the first pole, second and first shields and undercoat layer to the substrate in order to conduct heat away from the write head poles, insulating layers (e.g. photoresist) and shields.

A method is provided for fabricating a read element with leads that overlay a top surface of a sensor of the read element. The method includes forming a mask over a sensor layer, then using the mask to define the sensor from the sensor layer. The mask is then narrowed and a lead layer is formed that overlays both ends of the top surface of the sensor without covering a center portion of the top surface.