50results about How to "Optimizing spin polarizability" patented technology

The invention relates to a magnetic sandwich material based on nanometer crystal soft magnetic film and relative production, wherein said material is formed by separating two iron magnetic layers with one non-magnetic metal layer; it is characterized in that: one iron magnetic layer is nanometer crystal magnetic film while another one is multi-crystal magnetic film, whose total thickness is 10nm. The inventive material is prepared by direct-current magnetic-control splash method, with four-target splash device, and it on-site quickly anneals the material on the substrate support of four-target splash device, while the material has small interlayer couple, better magnetic resistance effect, and better thermal stability.

A magnetoresistive device including a high-resistivity layer (13), a first magnetic layer (12) and a second magnetic layer (14), the first magnetic layer (12) and the second magnetic layer (14) being arranged so as to sandwich the high-resistivity layer (13), wherein the high-resistivity layer (13) is a barrier for passing tunneling electrons between the first magnetic layer (12) and the second magnetic layer (14), and contains at least one element L_ONC selected from oxygen, nitrogen and carbon; at least one layer A selected from the first magnetic layer (12) and the second magnetic layer (14) contains at least one metal element M selected from Fe, Ni and Co, and an element R_CP different from the metal element M; and the element R_CP combines with the element L_ONC more easily in terms of energy than the metal element M. Accordingly, a novel magnetoresistive device having a low junction resistance and a high MR can be obtained.

The invention discloses a topological insulator heterogeneous composite film with a high spin polarized electron transport channel, and the topological insulator heterogeneous composite film comprises a 6H-SiC (0001) or SrTiO3 substrate and topological insulator 6QLBi2Se3 and ordinary semiconductor 3QLSb2S3 which are in order grown on the substrate by a molecular beam epitaxy technology in an ultra high vacuum system. Through coverage of the surface of topological insulator Bi2Se3 with the Sb2S3, the electrical properties of the composite film are significantly improved compared with that of a pure Bi2Se3 film; the Dirac point is changed from 0.1eV less than valence-band maximum to 0.09eV higher than valence-band maximum, Fermi velocity is improved from 1.15 eV. Angstrom to 1.61eV. Angstrom, spin polarization rate is also increased from 0.65 to 0.91; at the same time, the width of the spin polarized electron transport channel is improved from about 1nm to 3nm, and can be further expanded according to the needs by increasing of the Sb2S3 covering layer thickness; and the Sb2S3 covering layer can reduce influence on the spin polarized electron flow transport channel due to surface contamination such as oxidation and the like.

A magnetoresistive sensor comprises a pinned layer having a magnetization direction fixed with respect to an external magnetic field, a free layer, having a magnetization direction variable in accordance with the external magnetic field, and a spacer layer mainly containing copper, sandwiched between the pinned layer and the free layer. A sense current flows through the pinned layer, the spacer layer, and the free layer substantially in a direction in which the layers are stacked. The free layer comprises at least one intermediate stack composed of a non-magnetic layer mainly containing copper, and a first cobalt iron layers made of a cobalt iron alloy and disposed on boundaries on both sides of the non-magnetic layer, a nickel iron alloy layers disposed on boundaries on both sides of the intermediate stack, and a second cobalt iron layer made of a cobalt iron alloy and formed in contact with the spacer layer on a boundary, opposing the spacer layer, of a stack composed of the intermediate stack and the nickel iron alloy layer.

This invention relates to a metallic magnetic material with high spin polarizability having the following formula: Mnx CoyNzMw, among which, N is the element of III-V group, such as one or many of Al, Ga, In, Si, Ge, Sn and Sb, M is the transition group element: V, Cr Fe and Ni, x is less than or equal to 2.2 but greater or equal to 1.8, y is less than or equal to 1.2 but greater or equal to o, z is less than or equal to 1.2 but greater than o, w is less than or equal to 0.99 but greater or equal to o and x +y+z+w=4. The maximum spin polarizability in the material is 100%, which is a typical semi-metal magnetic material and the minimum is 80%.

A tunneling magnetic sensing element includes a free magnetic layer disposed on an insulating barrier layer, the free magnetic layer including an enhancement layer, a first soft magnetic layer, a first nonmagnetic metal layer, a second soft magnetic layer, a second nonmagnetic metal layer, and a third soft magnetic layer disposed in that order from the bottom. The enhancement layer is, for example, composed of Co—Fe, each of the soft magnetic layers is, for example, composed of Ni—Fe, and each of the nonmagnetic metal layers is, for example, composed of Ta. Consequently, it is possible to stably obtain a high rate of change in resistance (ΔR/R) compared with the known art.

The invention relates to a semi-metal synthetic anti-ferromagnetic structure, which belongs to the technical field of magnetic storage. The semi-metal synthetic anti-ferromagnetic structure has the characteristics that an A2BC-type Heusler alloy material of which all Co occupy an A position is used as a magnetic layer to form the sandwich structure of a semi-metal layer/a ruthenium layer/a semi-metal layer; and the magnetic directions of both semi-metal layers realize anti-ferromagnetic coupling. The semi-metal synthetic anti-ferromagnetic structure has the advantages that in the semi-metal synthetic anti-ferromagnetic structure, a cobalt element in the semi-metal material and metal ruthenium can form strong anti-ferromagnetic coupling to ensure the anti-ferromagnetic coupling configuration of a three-layer film; and simultaneously, high-spin polarization, low-saturation magnetization and low-coercivity semi-metal material is used as the magnetic layer, the semi-metal synthetic anti-ferromagnetic structure can reduce the magnetic flip field of a device, improve magnetic resistivity and thermal stability, and make ultra-high storage density become possible.

The invention provides a production method of a half-metallic Heusler alloy Co2FeAl nanowire. The production method comprises obtaining Co2FeAl Heusler alloy particles through production by a wet chemical method and growing into the Co2FeAl Heusler alloy nanowire in a vacuum tube furnace under the protection of the 99.99% purity of argon gas through the alloy particles. According to the Co2FeAl nanowire produced by the production method, the spin polarization rate is high, the Curie temperature is high, the high magnetoresistance effect can be obtained when the Co2FeAl nanowire obtained through production is applied to a spin valve multilayer-membrane structure and the spinning electron detection, and the use requirements of high sensitivity and storage density of magnetic sensors and magnetic memories are met. According to the production method of the half-metallic Heusler alloy Co2FeAl nanowire, large instruments and devices are not required, complicated process parameters which are difficult to be accurately controlled do not need to be controlled, and accordingly the production process is simple, the cost is low, the efficiency is high, the Co2FeAl nanowire obtained through production is good in structure and good in repetition, and the mass production is convenient.

The invention discloses a Co2VGa/PbS interface half-metallic preparation technology, which comprises the following steps of (1) building interface structures; (2) carrying out structure optimization on four interfaces, wherein during the optimization process, in order to close to practice, atoms in five atom layers closest to the interfaces are allowed to be subjected to location relaxation, and other atoms are fixed in position; (3) calculating physical quantities such as state density, magnetic moment and surface energy of the optimized interface structures; (4) analyzing the state density, the magnetic moment, spin polarization and stability of the interface structures; (5) through analyzing and comparing graphics and forms in the step (4), obtaining a half-metallic interface thin film with 100 percent spin polarization and stable structure.

A magnetoresistance effect element has favorable symmetry of an MR ratio even if the sign of a bias voltage is different, which is capable of reversing magnetization to a current, which has a high MR ratio. A magnetoresistance effect element includes a laminate in which an underlayer, a first ferromagnetic metal layer, a tunnel barrier layer, and a second ferromagnetic metal layer are laminated in that order, wherein the underlayer is made of one or more selected from a group containing of TiN, VN, NbN, and TaN, or mixed crystals thereof, and wherein the tunnel barrier layer is made of a compound having a spinel structure and represented by the following composition formula (1). (1): A_xGa₂O_y where A is a non-magnetic divalent cation and represents a cation of at least one element selected from the group consisting of magnesium, zinc, and cadmium, x is a number that satisfies 0<x≦2, and y is a number that satisfies 0<y≦4.

The invention provides a magneto-resistor element with a three-decker memory layer. The magneto-resistor element comprises a reference layer, a barrier layer, the memory layer, a crystal lattice optimizing layer and a base layer which are sequentially adjacent to one another. The magnetization direction of the reference layer is unchanged, and the magnetic anisotropy of the reference layer is perpendicular to the layer surface. The magnetization direction of the memory layer is changed, and the magnetic anisotropy of the memory layer is perpendicular to the layer surface. The memory layer is composed of a first memory sub layer, a second memory sub layer and an inserting layer arranged between the first memory sub layer and the second memory sub layer, wherein the first memory sub layer, the second memory sub layer and the inserting layer are sequentially arranged adjacent to one another. The barrier layer is adjacent to the first memory sub layer. The crystal lattice optimizing layer is adjacent to the second memory sub layer, the crystal lattice optimizing layer is a material layer of a NaCl crystal lattice structure, and the crystal face of the crystal lattice optimizing layer is parallel to the plane of a base. The crystal lattice optimizing layer further includes at least one doping element, and the crystal lattice optimizing layer further can be of a double-decker structure. The magneto-resistor element further comprises a magnetic calibration layer and a spin polarization stable layer, and the magnetic calibration layer and the spin polarization stable layer are sequentially arranged between the base layer and the crystal lattice optimizing layer.

The invention relates to a heterojunction high electron mobility spinning field effect transistor and a manufacturing method. The transistor comprises a 3C-SiC drain region, a 3C-SiC source region, a 3C-SiC channel region, a Schottky contact gate electrode, an Si substrate, a drain electrode, a source electrode, and an SiN isolation layer. The 3C-SiC drain region, the 3C-SiC source region and the 3C-SiC channel region are located on the Si substrate. The source electrode is located in the 3C-SiC source region, the Schottky contact gate electrode is located in the 3C-SiC channel region, and the drain electrode is located in the 3C-SiC drain region. The SiN isolation layer is located between the source electrode and the Schottky contact gate electrode and between the Schottky contact gate electrode and the drain electrode. The transistor can change the doping density and defect density of source-drain materials through adjusting the dosage and annealing time of ion injection, thereby optimizing the spinning polarizability of the drain region and the source region under room temperature.

The invention is concerned with spin valve magnetoresistance device using for hard magnetism material. It relates to an underlay and its cushion layer, and there are hard magnetism layer, the first soft magnetism layer, non-magnetism metal conducting layer or insulated layer, the second soft magnetism layer and cover layer. The hard magnetism layer is made up of ferromagnetic material with high remanence and big coercive force. The soft magnetism layer is made up of ferromagnetic material with high spin polarization ratio and small coercive force. This device relates to ferromagnetic/antiferromagnetic coupling layer between the hard magnetism layer and the first soft magnetism layer. The said hard magnetism layer is complex hard magnetism layer, while the second soft magnetism layer is complex soft magnetism layer. This device is made up by vacuum plating method to form the said layer on the monocrystal underlay in turn. It owns high stability of heat without the thermal diffusion of Mn, and is fit for giant magnetoresistance device and tunnelling magnetoresistance device.

Provided is a magnetoresistance effect element that that generates a high MR ratio at a lower RA than a TMR element using a material of a conventional tunnel barrier layer or MgAl₂O₄. The magnetoresistance effect element includes a laminate in which an underlayer, a first ferromagnetic metal layer, a tunnel harrier layer, and a second ferromagnetic metal layer are laminated in that order, wherein the underlayer is made of TiN, NbN, TaN, ZrN or mixed crystals thereof, and the tunnel barrier layer is made of a compound that has a spinel structure and expressed by composition formula (1) below: (1) A_xIn₂O_y, where A is the non-magnetic divalent cation and represents cations of one or more elements selected from the group consisting of magnesium and zinc, x represents a number satisfying 0<x≦2, and y represents a number satisfying 0<y≦4.

The invention discloses an MnGa-base vertical magnetic tunnel junction taking a Heusler alloy as an intercalation. The MnGa-base vertical magnetic tunnel junction comprises a substrate which is the base for realizing epitaxial growth of a multilayer film; a buffer layer which is manufactured on the substrate and is used for smoothing the surface of the substrate and reducing crystal lattice mismatch; a lower electrode which is manufactured on the buffer layer and grows in an epitaxial mode; a lower intercalation which is manufactured on the lower electrode and grows in an epitaxial mode; a barrier layer which is manufactured on the lower intercalation; an upper intercalation which is manufactured on the barrier layer and grows in an epitaxial mode; an upper electrode which is manufactured on the upper interaction and grows in an epitaxial mode; and a coverage layer which is manufactured on the upper electrode and protects a lower-layer structure. The MnGa-base vertical magnetic tunnel junction has a quite high tunneling magnetoresistance effect.

The invention discloses a magnetic tunnel junction forming method comprising the steps of providing a substrate on which a bottom electrode is formed; and forming a magnetic tunnel junction on the bottom electrode, wherein the magnetic tunnel junction is composed of a first magnetic layer, a tunneling layer and a second magnetic layer sequentially stacked from the bottom up, both the first magnetic layer and the second magnetic layer have vertical anisotropy, when a current from the second magnetic layer to the first magnetic layer exists, the magnetic moment direction of the second magnetic layer is the same as that of the first magnetic layer, and when the direction of the current is opposite, the magnetic moment direction of the second magnetic layer is opposite to that of the first magnetic layer; ferromagnetic particles are injected into the junction of the tunneling layer and the first magnetic layer; and the magnetic moment direction of the ferromagnetic particles is the same asthat of the first magnetic layer. According to the method, the tunneling resistance ratio of the magnetic tunnel junction is improved, the property of the magnetic layer is not changed, and thus thenegative effects are not generated on the other magnetoelectric parameters of the tunnel junction. The invention also discloses a magnetic resistance random access memory.

The invention relates to a heterojunction spinning field effect transistor based on a 4H-SiC substrate, and a manufacturing method for the heterojunction spinning field effect transistor. The method comprises the following steps: selecting the 4H-SiC substrate; growing a Ga2O3 epitaxial layer on the surface of the 4H-SiC substrate through employing the MBE technology; forming a source region and a drain region on the Ga2O3 epitaxial layer through the ion implantation technology; respectively forming a source region ohmic contact electrode and a drain region ohmic contact electrode in the resource region and the drain region; growing an oxidation layer on the Ga2O3 epitaxial layer, and carrying out the etching to form a grid region; forming a Schottky contact grid electrode on the surface of the grid region through the technology of magnetron sputtering, and finally forming the heterojunction spinning field effect transistor based on the4H-SiC substrate. According to the invention, the source and drain regions are formed in a mode of selecting regions and carrying out the implantation of Fe ions. The method is compatible with the conventional technology, is simple in manufacturing, is small in surface effect, and can improve the spinning injection and receiving efficiency.

The invention relates to static memories applying multiple magnetic layers, in particular to a tunneling magneto-resistance multilayer film material. The TMR (tunneling magneto-resistance) multilayer film material is of a high-spin polarizability interface (CoTiSb)x/Fey/(CoTiSb)z superlattice structure, wherein the x, the y and the z refer to the atom layer number of each component, the superlattice structure is a multilayer film structure which grows coherently along the direction of a semi-Heusler structure CoTiSb single crystal [100] by taking a three-layer film as a basic unit and is capable of achieving periodic epitaxy by taking the basic unit as a base, and in an inserted Fe layer and a high-spin polarization layer induced by the same, a few vacancy or island-shaped defects cannot have a great influence on high-spin polarizability. The tunneling magneto-resistance multilayer film material overcomes the defect that unmatching of multilayer film interfaces of a TMR material in practical use and unmatching of electronic structures of different interlayer materials can have adverse influences on practical spin polarizability and magneto-resistance in the prior art.