194 results about "Spintronics" patented technology

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 ferromagnetic tunnel junction structure comprising a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer, wherein the tunnel barrier layer includes a crystalline non-magnetic material having constituent elements that are similar to those of an crystalline oxide that has spinel structure as a stable phase structure; the non-magnetic material has a cubic structure having a symmetry of space group Fm-3m or F-43m in which atomic arrangement in the spinel structure is disordered; and an effective lattice constant of the cubic structure is substantially half of the lattice constant of the oxide of the spinel structure.

A spin valve structure is disclosed in which an AP1 layer and/or free layer are made of a laminated Heusler alloy having Al or FeCo insertion layers. The ordering temperature of a Heusler alloy such as Co₂MnSi is thereby lowered from about 350° C. to 280° C. which becomes practical for spintronics device applications. The insertion layer is 0.5 to 5 Angstroms thick and may also be Sn, Ge, Ga, Sb, or Cr. The AP1 layer or free layer can contain one or two additional FeCo layers to give a configuration represented by FeCo/[HA/IL]_nHA, [HA/IL]_nHA/FeCo, or FeCo/[HA/IL]_nHA/FeCo where n is an integer≧1, HA is a Heusler alloy layer, and IL is an insertion layer. Optionally, a Heusler alloy insertion scheme is possible by doping Al or FeCo in the HA layer. For example, Co₂MnSi may be co-sputtered with an Al or FeCo target or with a Co₂MnAl or Co₂FeSi target.

The invention relates to a method for changing spin relaxation, a method for detecting a spin current, and a spintronic device using spin relaxation, and spin relaxation is changed through injection of a spin current.

A spin current 4 is injected into a material 1 in a certain spin state, so that the spin relaxation time can be controlled.

Graphene magnet multilayers (GMMs) are employed to facilitate development of spintronic devices. The GMMs can include a sheet of monolayer (ML) or few-layer (FL) graphene in contact with a magnetic material, such as a ferromagnetic (FM) or an antiferromagnetic material. Electrode terminals can be disposed on the GMMs to be in electrical contact with the graphene. A magnetic field effect is induced in the graphene sheet based on an exchange magnetic field resulting from a magnetization of the magnetic material which is in contact with graphene. Electrical characteristics of the graphene can be manipulated based on the magnetization of the magnetic material in the GMM.

The present invention relates to using spin transfer torque underneath a nanocontact on a magnetic thin film with perpendicular magnetic anisotropy (PMA), provides generation of dissipative magnetic droplet solitons and magnetic droplet-skyrmions and report on their rich dynamical properties. Micromagnetic simulations identify the conditions necessary to nucleate and drive droplet-skyrmions over a wide range of currents and fields. Micromagnetic simulations also demonstrate how droplets and droplet-skyrmions can be used as skyrmion injectors and detectors in skyrmion-based magnetic memories. The droplet-skyrmion can be controlled using both current and magnetic fields, and is expected to have applications in spintronics, magnonics, skyrmionics, and PMA-based domain-wall devices.

The invention provides a preparation method of ultrathin graphite phase carbon nitride. The preparation method comprises steps as follows: melamine is calcined firstly, and blocky g-C3N4 is obtained; blocky g-C3N4 is uniformly dispersed in deionized water and subjected to ultrasonication; a product obtained after ultrasonication is subjected to centrifugal separation, and solids are collected and dried; finally, a dried product is calcined again, and a target product is obtained. According to the preparation method of ultrathin graphite phase carbon nitride, mass preparation and thickness regulation of ultrathin g-C3N4 with the thickness of 0.8-1.2 nm equal to the thickness of 3-4 atom layers are realized, no organic solvent or toxic chemical reagent participates in a reaction process, so that the problems of structure defects and environmental pollution which are caused by introduction of impurities can be effectively solved, and on the basis of the non-toxic characteristic of prepared g-C3N4, the preparation method can be widely applied to photocatalysis, electro-catalysis, biosensing, bioimaging and spintronics. The whole preparation process is simple to operate, high in controllability, good in repeatability, green, environment-friendly and suitable for large-scale production.

Synthesis of TiO2 nanometer granules and rod is characterized by taking organic titanate ester or long-chain organic hydroxy acid or NH4HCO3 as raw materials under the existence of heat solvent, taking organic amine as mineralizer, taking low-boiling point organic matter as solvent, reacting at 100~200 degrees C in closed reactor, synthesizing TiO2 nanometer granules and rod with high crystallinity, homogeneous size and re-dispersion organic solvent, doping other metal ions into reactive system and forming TiO2 nanometer granules or rod doped with metal. It is simple and cheap, has better process reproducibility and quality. It can be used for battery electrode, catalyst, light catalyst and solar battery.

The present invention relates to a fabrication method of gallium manganese nitride (GaMnN) single crystal nanowire, more particularly to a fabrication method of GaMnN single crystal nanowire substrate by halide vapor phase epitaxy (HVPE) in which such metal components as gallium (Ga) and manganese (Mn) react with such gas components as nitrogen (N₂), hydrogen chloride (HCl) and ammonia (NH₃), wherein the amount of the gas components are adjusted to control the Mn doping concentration in order to obtain nanowire having a perfect, one-dimensional, single crystal structure without internal defect, concentration of holes, or carriers, and magnetization value of which being determined by the doping concentration and showing ferromagnetism at room temperature, thus being a useful spin transporter in the field of the next-generation spintronics, such as spin-polarized LED, spin-polarized FET, etc.

The invention discloses a method for preparing an oriented graphene nanoribbon array. As one of optimized schemes, the method includes the following steps of (1) depositing nano-metal catalyst particles on a substrate surface which is subjected to a polishing process; (2) growing a directionally distributed carbon nanotube on the substrate surface; (3) depositing a thin layer hydrogen front metal film on the substrate surface; and (4) processing the substrate surface with an acid solution and dissecting the carbon nanotube along the axial direction to form the graphene nanoribbon array. The method for preparing the oriented graphene nanoribbon array has the advantages that the process is simple, the method is easy to implement, the prepared GNR has a high directionality, a high density, low in-plane defect density and edge disorder and a high electron mobility, the density and the like of the GNR array can be controlled through a growth technology and an etching process of a directional carbon tube, simultaneously a device based on the GNR array has a good electrical conduction performance, and the method has a significant application prospect in fields of spintronics, sensors, transistors and the like.

The invention relates to a fluorenyl windmill grid material and a preparation and application method thereof, and belongs to the field of organic molecular materials and high and new photoelectric technologies. The fluorenyl windmill grid material is cyclic oligomer with fluorenyl micromolecules as monomers, and the specific general structural formula is shown in the description. The material has the advantages that the fluorenyl windmill grid material has both porous characteristics and semiconductor photoelectric characteristics; raw materials are cheap and easy to obtain, reaction conditions are mild, and operation is easy; the fluorenyl windmill grid material has good mechanical properties of a nanomaterial; the fluorenyl windmill grid material has good solubility, and nanofilm processing or fibration processing is facilitated; with a rigid framework, the fluorenyl windmill grid material is high in glass transition temperature, high in thermal stability, electrochemical stability and spectrum stability and the like. Thus, the fluorenyl windmill grid material is expected to become a new-generation practical organic micromolecular photoelectric material and has good application prospects in the fields of organic electronics, spintronics, optoelectronics, mechatronics, nanobiology and the like.

The invention discloses an FM/NM thin-film structure inverse spin hall voltage value measurement method, and belongs to the field of spintronics research and manufacturing of the related spin devices. Voltage of the two ends of a sample is measured at configuration that the film surface is upward and then the film surface is downward by adopting a mode that the sample is vertically overturned in a microstrip line jig based on a method that spin pump-inverse spin hall effect voltage of the FM/NM thin-film structure sample is tested by utilizing a terminal short-circuit suspended microstrip transmission line jig. A spin rectification component and an inverse spin hall effect voltage component in measurement voltage can be accurately obtained by simple calculation according to difference of opposite direction of spin injection in the configuration of the sample so that reference is provided for accurate calculation of a spin hall angle.

The invention discloses a layered-structure asymmetric MXene (abbreviated as aMXene) and a derived heterojunction thereof. After one of top or bottom passivating functional group layers of a layered-structure symmetric MXene is removed, an aMXen with a high dipole moment is obtained. Proper single-layer transition metal disulfide (mTMDC) is selected to carry out passivation on one exposed side ofthe aMXen, so that an aMXen/mTMDC heterojunction is derived from the aMXen. According to the aMXen/mTMDC heterojunction, different layers have the high potential difference, so that charges between two-dimensional structures are allocated again conveniently and thus the energy band structure, relative positions of band edges, and generation and changing of carriers are controlled. Therefore, the aMXene/TMDC heterojunction has the great competitiveness in the electronics and chemical application fields and has broad application prospects in fields of spintronics, electronics/ photoelectron, andcatalyzation/photocatalysis.

The invention relates to a regulation and control method based on the energy valley polarization characteristic of a two-dimensional single-layer transition metal chalcogenide. The method comprises the following steps of: (1) growing a two-dimensional single-layer transition metal chalcogenide on a substrate by adopting a chemical vapor deposition method; (2) preparing two-dimensional ferromagnetic metal by adopting a mechanical stripping method; and (3) transferring the two-dimensional ferromagnetic metal to the two-dimensional single-layer transition metal chalcogenide in an aligning mannerthrough an aligning transfer platform to form a two-dimensional single-layer transition metal chalcogenide-two-dimensional ferromagnetic metal heterostructure. The heterostructure is formed by the two-dimensional ferromagnetic metal material and the two-dimensional single-layer transition metal chalcogenide, so that the characteristics of flexibility and atomic-level thinness of the two-dimensional material can be fully exerted, the problem that the characteristics of the two-dimensional material are damaged due to the three-dimensional-two-dimensional heterostructure formed by the traditionalferromagnetic metal material and the two-dimensional material is effectively solved, and the regulation and control method based on the energy valley polarization characteristic of a two-dimensionalsingle-layer transition metal chalcogenide can be applied to development and research of ultrathin microminiaturization, flexible spintronics, energy valley electronic devices and the like.

The invention discloses a method for controlling spin wave transmission and belongs to the field of spintronics. According to the method, through applying an electric field on a spin wave guide structure, the strength of exchange interaction in a magnetic waveguide material can be effectively changed. An exchange constant is controlled through the electric field, so that the spin wave dispersion relation can be regulated to realize a purpose of controlling the spin wave transmission. The exchange interaction is controlled through the electric field, so that the local precise control of the spin wave transmission can be realized at ultra-low power consumption to provide the possibility for actual application of an ultra-low-power magnonics device compatible with a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) technological process.

The invention relates to a controllable graphene nanolayer preparation method. The method comprises the steps that graphite powder is put into a reaction container, a solvent is injected into the reaction container, ultrasonic vibration is conducted, and a stirrer is started, so that the raw material-graphite powder is fully and uniformly distributed in the solvent; a laser path is adjusted, so that laser beams sequentially pass through a total reflective mirror and a focus lens and then are focused at the position 3 mm below the liquid level; a pulse laser is started, different kinds of laser energy are adjusted to enable laser light to irradiate graphite particles in a liquid environment, after the reaction process lasts 1 h to 2 h, the laser is stopped, and finally graphene with the different layer numbers can be obtained. The method is easy to operate, controllable in layer number and free of toxins and pollution and has potential application in the fields of nanometer equipment and spintronics.

The invention generally relates to the field of spintronics, a branch of electronics using the magnetic spin properties of electrons. More particularly, the invention relates to the field of spin-valve transistors which can be used in numerous fields of electronics. The invention aims to propose an original arrangement for producing high-level and high-contrast collector currents simultaneously. The inventive spintronics transistor comprises a semiconductor emitter, a base fanning a spin valve and a metallic collector separated from the base by an insulating deposit. The emitter/base interface constitutes a Schottky barrier and the base/collector interface constitutes a tunnel-effect barrier.

[Problem to be Solved]

To realize a spintronics device with high performance, it is an object of the present invention to provide a Co₂Fe-based Heusler alloy having a spin polarization larger than 0.65, and a high performance spintronics devices using the same.

[Solution]

A Co₂Fe(Ga_xGe_1-x) Heusler alloy shows a spin polarization higher than 0.65 by a PCAR method in a region of 0.25<x<0.60 and it has a Curie temperature as high as 1288K. A CPP-GMR device that uses the Co₂Fe(Ga_xGe_1-x) Heusler alloy as an electrode exhibits the world's highest MR ratio, an STO device exhibits high output, and an NLSV device exhibits a high spin signal.