30 results about "Spin diffusion" patented technology

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, spacer, free, and spin barrier layers. The spacer layer is nonmagnetic and 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 resides between the spacer layer and the spin barrier layer. The spin barrier layer is configured to reduce an outer surface contribution to a damping constant of the free layer. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity, preferably being metallic, and may have a long spin diffusion length.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes first pinned, spacer, free, spin barrier, and second pinned layers. The spacer layer is nonmagnetic and 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 resides between the spacer and spin barrier layers. The spin barrier layer is between the free and second pinned layers. The spin barrier layer is configured to reduce an outer surface contribution to the free layer damping constant. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity and may have a long spin diffusion length.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, spacer, free, and spin barrier layers. The spacer layer is nonmagnetic and 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 resides between the spacer layer and the spin barrier layer. The spin barrier layer is configured to reduce an outer surface contribution to a damping constant of the free layer. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity, preferably being metallic, and may have a long spin diffusion length.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes first pinned, spacer, free, spin barrier, and second pinned layers. The spacer layer is nonmagnetic and 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 resides between the spacer and spin barrier layers. The spin barrier layer is between the free and second pinned layers. The spin barrier layer is configured to reduce an outer surface contribution to the free layer damping constant. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity and may have a long spin diffusion length.

A magnetic sensor reduces thermal fluctuation and realizes high-sensitive signal detection using a spin Hall device of a simple structure configured with only one magnetic layer. The magnetic sensor includes a stacked film in which a nonmagnetic spin Hall layer, a nonmagnetic insulator layer, and a magnetic layer are stacked, an electrode nonmagnetic terminal pair connected to a side surface of the nonmagnetic spin Hall layer, and a unit applying a current in a film thickness direction of the stacked film. A thickness of the nonmagnetic spin Hall layer is thinner than twice a spin diffusion length of a material constituting the nonmagnetic spin Hall layer. A magnetization direction of the magnetic layer magnetized by an external magnetic field is detected due to the polarity of a voltage across both ends of the electrode nonmagnetic terminal pair.

A magnetic sensor reduces thermal fluctuation and realizes high-sensitive signal detection using a spin Hall device of a simple structure configured with only one magnetic layer. The magnetic sensor includes a stacked film in which a nonmagnetic spin Hall layer, a nonmagnetic insulator layer, and a magnetic layer are stacked, an electrode nonmagnetic terminal pair connected to a side surface of the nonmagnetic spin Hall layer, and a unit applying a current in a film thickness direction of the stacked film. A thickness of the nonmagnetic spin Hall layer is thinner than twice a spin diffusion length of a material constituting the nonmagnetic spin Hall layer. A magnetization direction of the magnetic layer magnetized by an external magnetic field is detected due to the polarity of a voltage across both ends of the electrode nonmagnetic terminal pair.

A first and a second tunnel junctions (2 and 3) which have a common electrode composed of a nonmagnetic conductor (4) and each of which has a counterelectrode composed of a ferromagnet (6, 8) are disposed spaced apart from each other by a distance that is shorter than a spin diffusion length of the nonmagnetic conductor (4) wherein the first tunnel junction (2) acts to inject spins from the ferromagnet (6) into the nonmagnetic conductor (4) and the second tunnel junction (3) serves to detect, between the ferromagnetic metal (8) and the nonmagnetic conductor (4), a voltage that accompanies spin injection of the first tunnel junction (2) and wherein the nonmagnetic conductor (4) is a nonmagnetic conductor, such as a semiconductor or a semimetal, that is lower in carrier density than a metal. The common electrode alternatively may be composed of a superconductor (4′). A spin injection device thus provided can exhibit a large signal voltage with low current and under low magnetic field and can be miniaturized in device size. Magnetic apparatuses utilizing such a spin injection device are also provided.

The present disclosure generally relates to a SOT-MRAM cell that has a spin Hall effect layer and a magnetic tunnel junction. The magnetic tunnel junction is disposed at an edge of the spin Hall effect layer. In order to write the cell, current is applied through the spin Hall effect layer to create spin accumulation of z-polarized spins under the free layer due to the spin Hall effect. The spins exert a spin torque on the free layer via spin diffusion. Based upon the design, the SOT-MRAM cell has deterministic switching of the perpendicular free layer with the spin Hall effect layer without application of an external magnetic field.

A spin accumulation sensor having a three terminal design that allows the free layer to be located at the air bearing surface. A non-magnetic conductive spin transport layer extends from a free layer structure (located at the ABS) to a reference layer structure removed from the ABS. The sensor includes a current or voltage source for applying a current across a reference layer structure. The current or voltage source has a lead that is connected with the non-magnetic spin transport layer and also to electric ground. Circuitry for measuring a signal voltage measures a voltage between a shield that is electrically connected with the free layer structure and the ground. The free layer structure can include a spin diffusion layer that ensures that all spin current is completely dissipated before reaching the lead to the voltage source, thereby preventing shunting of the spin current to the voltage source.

The invention relates to a perpendicular magnetic anisotropic multi-layered film, which comprises a substrate, a bottom layer, a lower magnetic layer, a middle layer, an upper magnetic layer and a covering layer, wherein at least one of the lower magnetic layer and the upper magnetic layer is a composite magnetic layer which consists of a main layer and a transitional layer, the main layer is made of perpendicular magnetic anisotropic material, and the transitional layer is made of magnetic metal material with spin polarization higher than the spin polarization of the perpendicular magnetic anisotropic material, and is positioned between the main layer and the middle layer. When the middle layer is a barrier layer, the composite magnetic layer also can be made of metal material with a spin diffusion length larger than 3nm. Under the premise of guaranteeing excellent perpendicular magnetic anisotropy, the invention can enhance the magnetoresistance property, reduce mutual magnetostatic reaction and decrease the reverse field or reverse current of a corresponding device. The invention is applicable to giant magnetoresistance devices or tunneling magnetoresistance devices, such as magnetic sensors, magnetic random-access memorys and magnetic logic devices.

To provide a magnetic reading head that features high resolution and low noise, and that can support a hard disk with terabit-level surface recording density. A current is caused to flow from a pinned layer with its magnetization direction fixed by an antiferro magnetic material, to a non-magnetic thin wire having a portion affected by an external magnetic field and a portion not affected by the external magnetic field, so that spin polarized electrons are accumulated in the non-magnetic thin wire. A distance between voltage terminals of a voltmeter is set to less than the spin diffusion length of the non-magnetic thin wire. A change in the external magnetic field modulates some of the accumulated spin polarized electron, but does not others. Accordingly, an electrical potential difference depending on the external magnetic field is generated between the both end surfaces of the non-magnetic thin wire, and measured with the voltmeter.

First and second tunnel junctions having a common electrode composed of a nonmagnetic conductor and each of which has a counterelectrode composed of a ferromagnet are spaced apart from each other by a distance that is shorter than a spin diffusion length of the nonmagnetic conductor. The first tunnel junction injects spin from the ferromagnet into the nonmagnetic conductor and the second tunnel junction detects, between the ferromagnetic metal and the nonmagnetic conductor, a voltage that accompanies spin injection of the first tunnel junction. The nonmagnetic conductor may be a semiconductor or semimetal that is lower in carrier density than a metal. The common electrode alternatively may be composed of a superconductor. A spin injection device thus provided can exhibit a large signal voltage with a low current and under low magnetic field and can be miniaturized in device size.

An NMR measurement method adapted for measurements on solid mixture samples starts with irradiating a pulse sequence to the sample in order to measure the longitudinal magnetization relaxation times of nuclei possessing homogeneous longitudinal magnetization relaxation times (step 1). After a lapse of a given period of time t, a high-resolution NMR spectrum is acquired by nullifying spin diffusion across the nuclei (step 2). The steps 1 and 2 are repeated while varying the period of time t. The high-resolution NMR spectra are classified according to value of longitudinal magnetization relaxation time by inverse Laplace transform.

A magnetization reversal device includes a ferromagnetic 12 body which is provided in an interconnection of a non-ferromagnetic dot 11 so that a part or a whole of the ferromagnetic dot is three-dimensionally buried in the interconnection of said non-ferromagnetic dot, and a spin injection source 13 which generates a spin-polarized pure spin current without a flow of charges, and which is provided in the interconnection of the non-ferromagnetic dot 11 to be in contact therewith so that the interconnection of the non-ferromagnetic dot serves as a common electrode, and the pure spin current flows into the ferromagnetic dot 2 through the interconnection of the non-magnetic body by the spin injection source 13 due to a diffusion current, to thereby reverse magnetization of the ferromagnetic dot 12. By injecting the pure spin current, using this planar structure, it is possible to easily carry out the magnetization reversal of the ferromagnetic dot 12 even if it is a thick film ferromagnetic dot without being subjected to limitation of a spin diffusion length.

A spin accumulation sensor having a three terminal design that allows the free layer to be located at the air bearing surface. A non-magnetic conductive spin transport layer extends from a free layer structure (located at the ABS) to a reference layer structure removed from the ABS. The sensor includes a current or voltage source for applying a current across a reference layer structure. The current or voltage source has a lead that is connected with the non-magnetic spin transport layer and also to electric ground. Circuitry for measuring a signal voltage measures a voltage between a shield that is electrically connected with the free layer structure and the ground. The free layer structure can include a spin diffusion layer that ensures that all spin current is completely dissipated before reaching the lead to the voltage source, thereby preventing shunting of the spin current to the voltage source.

A current-perpendicular-to-the-plane (CPP) magnetoresistive sensor has an antiparallel free (APF) structure as the free layer and a specific direction for the applied bias or sense current. The (APF) structure has a first free ferromagnetic (FL1), a second free ferromagnetic layer (FL2), and an antiparallel (AP) coupling (APC) layer that couples FL1 and FL2 together antiferromagnetically with the result that FL1 and FL2 have substantially antiparallel magnetization directions and rotate together in the presence of a magnetic field. The thicknesses of FL1 and FL2 are chosen to obtain the desired net free layer magnetic moment / area for the sensor, and the thickness of FL1 is preferably chosen to be greater than the spin-diffusion length of the electrons in the FL1 material to maximize the bulk spin-dependent scattering of electrons and thus maximize the sensor signal. The CPP sensor operates specifically with the conventional sense current (opposite the electron current) directed from the pinned ferromagnetic layer to the APF structure, which results in suppression of current-induced noise.

The invention provides an organic single-crystal spinning diode. The organic single-crystal spinning diode comprises two ferromagnetic electrodes. A micron-order channel is formed between the two ferromagnetic electrodes and covered with a transmission layer. The transmission layer is an organic semiconductor single crystal which is connected with the two ferromagnetic electrodes. The organic single crystal is adopted due to the fact that the structure of the organic single crystal is single, the quality of the crystal is good, defects, impurities, crystal boundaries and other influence factors can be avoided to the maximum degree, and the material spinning diffusion length can be increased to a large degree. Along with the increase of the carrier spinning diffusion length, the manufacturing difficulty of organic spinning electronic and photoelectronic devices can be lowered, and the important promoting effect on development of organic spinning electronics and organic spinning photoelectronics is achieved. Meanwhile, an organic single-crystal device with the large-distance organic transmission layer is manufactured, the influences of an external magnetic field on device characteristics are observed, and a certain experimental basis is provided for the research on the production mechanism of an organic magnetic resistor.

The invention provides a room-temperature high-spin Hall angle platinum-rare earth thin film material, and belongs to the technical field of new spin electronic materials. The thin-film material is aplatinum-rare earth alloy thin film growing on the surface of a substrate, in the platinum-rare earth alloy thin film, the molar percentage of the rare earth element is 1-60 mol%, and the molar percentage of the platinum is 40-99 mol%. The room-temperature high-spin Hall angle platinum-rare earth thin film material and a preparation method thereof are simple and feasible, compared with a pure platinum thin film, the room-temperature spin Hall angle of the platinum-rare earth thin film is obviously increased, and the room-temperature spin diffusion length of the platinum-rare earth thin film isreduced. Compared with the spin Hall effect of the pure platinum, the spin current generation efficiency is improved, the cost is reduced, it can be achieved that the platinum-rare earth thin film can be uniformly prepared on a semiconductor wafer on a large area, and a new method is provided for large-area preparation and research of the great spin Hall material.

The present disclosure generally relates to a SOT-MRAM cell that has a spin Hall effect layer and a magnetic tunnel junction. The magnetic tunnel junction is disposed at an edge of the spin Hall effect layer. In order to write the cell, current is applied through the spin Hall effect layer to create spin accumulation of z-polarized spins under the free layer due to the spin Hall effect. The spins exert a spin torque on the free layer via spin diffusion. Based upon the design, the SOT-MRAM cell has deterministic switching of the perpendicular free layer with the spin Hall effect layer without application of an external magnetic field.

A current-perpendicular-to-the-plane (CPP) magnetoresistive sensor has an antiparallel free (APF) structure as the free layer and a specific direction for the applied bias or sense current. The (APF) structure has a first free ferromagnetic (FL1), a second free ferromagnetic layer (FL2), and an antiparallel (AP) coupling (APC) layer that couples FL1 and FL2 together antiferromagnetically with the result that FL1 and FL2 have substantially antiparallel magnetization directions and rotate together in the presence of a magnetic field. The thickness of FL1 is preferably greater than the spin-diffusion length of the electrons in the FL1 material. The minimum thickness for FL2 is a thickness resulting in a FL2 magnetic moment equivalent to at least 10 Å Ni80Fe20 and preferably to at least 15 Å Ni80Fe20. The CPP sensor operates specifically with the conventional sense current (opposite the electron current) directed from the pinned ferromagnetic layer to the APF structure, which results in suppression of current-induced noise.

The invention relates to an optical test method for electron spin diffusion transport kinetics based on a pure phase liquid crystal spatial light modulator, wherein a one-dimensional pure phase liquid crystal spatial light modulator is combined with a time resolution pumping-detecting device, and the principle of an experimental device is indicated in the abstract figures. The one-dimensional pure phase liquid crystal spatial light modulator 7 is arranged in an overlapped area of a pumping light 2 and a detecting light 3, and is used for modulating circular polarization degrees of the cross sections of both the pumping light 2 and the detecting light 3 into the one-dimensional space period distribution. A modulation light field formed like this is imaged onto a sample 9 through an imaging lens 8. The modulated pumping light stimulates an electron spin polarization transient grating in the sample, and the modulated detecting light measures the decay kinetics of the electron spin polarization transient grating. An analytic model for the electron spin diffusion transport kinetics of the circular polarization one-dimensional sinusoidal and square wave type space period modulation light fields is provided. The method disclosed by the invention has the advantages of simple experimental device and operation, capability of testing the spin diffusion transport kinetics with the absorption saturation effect, and high sensitivity.

The invention discloses an organic single crystal spin valve and a preparation method and an application thereof. The organic single crystal spin valve includes a substrate, a ferromagnetic bottom electrode, an organic single crystal semiconductor micro / nano material, a buffer layer, a ferromagnetic top electrode and an oxidation protection layer. Because of the single structure and good crystal quality, influence of defects, impurities, grain boundaries and other factors on spin injection and scattering can be effectively avoided, moreover, the spin diffusion length of the material is increased to a large extent. The method is advantaged in that 1), a problem of large scattering of a spin injection interface caused by non-wetting of a ferromagnetic electrode of an organic semiconductor issolved; 2), the required equipment is relatively simple, universal and reproducible, and a new method for constructing the organic single crystal spin valve is provided; and 3), difficulty of preparation of the organic spintronic and optoelectronic device is reduced, and an important role in promoting development of organic spintronics and organic spintronics is played.

The invention relates to the field of environmental coal drying, and concretely relates to a safe and energy-saving environmental coal drying system, which comprises a rotational direct flow diffusiontype air distributor. An outlet of an internal circulating environmental coal drying machine is connected with a dry dedusting system; the rotational direct flow diffusion type air distributor comprises an air mixing pipe; one end of the air mixing pipe is a high-temperature flue gas inlet; the other end of the air mixing pipe is a mixed flue gas outlet; a low-temperature flue gas inlet is formedclose to a tangent direction of the high-temperature flue gas inlet end; a plurality of independent drying cavities are symmetrically arranged on the left side and the right side in the internal circulating environmental coal drying machine; a penetrating passage is formed in the middle; an upper air inlet passage, a middle return airway and a lower air inlet passage are arranged in the passage from top to bottom; the middle return airway is connected with the low-temperature flue gas inlet of the rotational direct flow diffusion type air distributor; and an outlet of the dry dedusting systemis connected with an inlet of a fan A and the low-temperature flue gas inlet of the rotational direct flow diffusion type air distributor. The safe and energy-saving environmental coal drying systemprovided by the invention is safe, high-efficient, energy-saving, environmentally-friendly, and suitable for improving an existing environmental coal drying system.

A magnetization reversal device includes a ferromagnetic 12 body which is provided in an interconnection of a non-ferromagnetic dot 11 so that a part or a whole of the ferromagnetic dot is three-dimensionally buried in the interconnection of said non-ferromagnetic dot, and a spin injection source 13 which generates a spin-polarized pure spin current without a flow of charges, and which is provided in the interconnection of the non-ferromagnetic dot 11 to be in contact therewith so that the interconnection of the non-ferromagnetic dot serves as a common electrode, and the pure spin current flows into the ferromagnetic dot 2 through the interconnection of the non-magnetic body by the spin injection source 13 due to a diffusion current, to thereby reverse magnetization of the ferromagnetic dot 12. By injecting the pure spin current, using this planar structure, it is possible to easily carry out the magnetization reversal of the ferromagnetic dot 12 even if it is a thick film ferromagnetic dot without being subjected to limitation of a spin diffusion length.

The invention relates to an optical test method for electron spin diffusion transport kinetics based on a pure phase liquid crystal spatial light modulator, wherein a one-dimensional pure phase liquid crystal spatial light modulator is combined with a time resolution pumping-detecting device, and the principle of an experimental device is indicated in the abstract figures. The one-dimensional pure phase liquid crystal spatial light modulator 7 is arranged in an overlapped area of a pumping light 2 and a detecting light 3, and is used for modulating circular polarization degrees of the cross sections of both the pumping light 2 and the detecting light 3 into the one-dimensional space period distribution. A modulation light field formed like this is imaged onto a sample 9 through an imaging lens 8. The modulated pumping light stimulates an electron spin polarization transient grating in the sample, and the modulated detecting light measures the decay kinetics of the electron spin polarization transient grating. An analytic model for the electron spin diffusion transport kinetics of the circular polarization one-dimensional sinusoidal and square wave type space period modulation light fields is provided. The method disclosed by the invention has the advantages of simple experimental device and operation, capability of testing the spin diffusion transport kinetics with the absorption saturation effect, and high sensitivity.

The invention relates to a perpendicular magnetic anisotropic multi-layered film, which comprises a substrate, a bottom layer, a lower magnetic layer, a middle layer, an upper magnetic layer and a covering layer, wherein at least one of the lower magnetic layer and the upper magnetic layer is a composite magnetic layer which consists of a main layer and a transitional layer, the main layer is made of perpendicular magnetic anisotropic material, and the transitional layer is made of magnetic metal material with spin polarization higher than the spin polarization of the perpendicular magnetic anisotropic material, and is positioned between the main layer and the middle layer. When the middle layer is a barrier layer, the composite magnetic layer also can be made of metal material with a spin diffusion length larger than 3nm. Under the premise of guaranteeing excellent perpendicular magnetic anisotropy, the invention can enhance the magnetoresistance property, reduce mutual magnetostaticreaction and decrease the reverse field or reverse current of a corresponding device. The invention is applicable to giant magnetoresistance devices or tunneling magnetoresistance devices, such as magnetic sensors, magnetic random-access memorys and magnetic logic devices.

The invention discloses a preparation process and application of a vertical-heterogeneous organic spin electronic device, belongs to the field of spin electronics, and combines the advantages of a transverse device and a longitudinal device. On the one hand, the invention avoids the problem of electrical short circuit of a vertical structure through transversely injecting spin polarization currentand transversely injecting the spin polarization current into an organic material; on the other hand, the electron spin is longitudinally detected, the length of the spin diffusion channel is the thickness of the thin film, the wedge-shaped organic thin film is adopted, and nano-scale continuous adjustment of the length of the spin diffusion channel is achieved, thereby achieving the control andutilization of electron spin in organic matter through an external electric field and a magnetic field in a multi-mode mode. The vertical-heterogeneous organic spin electronic device provided by the invention can be used for controlling the electron spin of spin diffusion length in a nano-scale material, can be used for the multi-mode control over the electron spin in the same device, and can achieve the magnetoresistive effect, the non-local magnetoresistance effect and a spin Hanle effect of an organic spin valve.