17 results about "Spin valve" patented technology

A device having a spin valve layer sequence, wherein the spin valve layer sequence includes a first magnetic layer having a variable direction of magnetization, a second magnetic layer having a fixed direction of magnetization, and a stabilization layer for stabilizing the fixed direction of magnetization of the second magnetic layer, wherein the stabilization layer includes a precious metal-free antiferromagnet.

The application discloses a preparation method of a nano or atomic scale spin valve, which comprises the following steps: preparing a buffer layer and a metal electrode on a substrate surface, preparing a magnetic metal point contact device based on a proximity effect photolithography method, placing the device on a vacuum probe station, preparing an atomic scale point contact structure by using a current feedback control method, and preparing a magnetic tunnel junction with a magnetic resistance of up to 40% by natural oxidation, so as to obtain the nano or atomic scale spin valve. The preparation method can effectively control the contact width of the atomic contact point, and compared with the prior art, the complexity of the spin valve structure is reduced, and the device power consumption is reduced to a certain extent. The preparation method is simple, the magnetic tunnel junction has a large magnetic resistance, and is compatible with a traditional CMOS process, so that an advantage is provided for the integration of subsequent devices.

The invention discloses a giant magnetoresistance magnetic sensor and a preparation method thereof, and relates to the field of magnetic sensor preparation, and the giant magnetoresistance magnetic sensor is configured to be a flexible stress adaptive magnetic sensor structure. The flexible stress self-adaptive magnetic sensor structure comprises a flexible substrate, a gradient buffer layer, a self-repairing interface layer, a GMR functional layer and a flexible electrode which are sequentially arranged from bottom to top, wherein the flexible substrate is polyimide or thermoplastic polyurethane; the gradient buffer layer is a composite gradient film, the self-repairing interface layer is a graphene quantum dot layer modified by polydopamine, and the GMR functional layer is of a spin valve structure; according to the giant magnetoresistance magnetic sensor and the preparation method thereof, the stress self-adaption framework of the gradient buffer layer, the self-repairing interface layer, the flexible electrode and the GMR functional layer is designed on the structural level, and a low-temperature double-effect preparation process is adopted on the process level, so that the stress self-adaption and the performance stability can be further enhanced; and high-reliability and high-sensitivity magnetic sensing requirements under flexible scenes such as wearable equipment and the like can be met.

The application discloses a magnetic recording device, a multi-state disk and a read-write method, and belongs to the field of magnetic storage. The magnetic recording device comprises a substrate and a magnetic recording film above the substrate. The magnetic recording film is circular and comprises three ferromagnetic layers separated by two non-magnetic intermediate layers. The easy magnetization directions of the three ferromagnetic layers are along the x, y and z directions respectively. The z direction is the vertical direction, and the x and y directions are in-plane directions and are along the radial direction and the tangential direction respectively. The multi-state disk comprises the magnetic recording device, a read head, a write head and magnetic shielding layers on both sides of the read head. The write head comprises a vertical magnetic pole and two pairs of horizontal magnetic poles, and coils wound on the magnetic poles. The read head comprises a spin current generation layer and a film layer structure (a magnetic tunnel junction, a spin valve or a Hall bar). The application can improve the storage density of the magnetic recording device, thereby greatly improving the storage density of the disk based on the magnetic recording device.

This invention discloses a magnetocaloric voltage excitation device and measurement method, comprising the following steps: In order to obtain a large temperature gradient, a magnetocaloric material with an anomalous magnetocaloric effect is deposited on the lower surface of a spin valve, and a magnetocaloric material with a normal magnetocaloric effect is deposited on the upper surface. By applying a pulsed magnetic field, positive and negative temperature gradients are formed on the upper and lower surfaces of the spin valve, thereby generating an AC thermoelectric voltage pulse. This technology is the first to combine magnetocaloric material with spintronic devices. The sample structure is simple and the measurement is convenient, which is conducive to promoting the application of spintronic devices and the development of spin thermoelectronics.

The invention provides a double-spin torque tunnel junction device and a preparation method thereof. The device comprises a double-spin torque tunnel junction. The double-spin torque tunnel junction sequentially comprises a bottom reference layer, a barrier layer, a free layer, a metal isolation layer and a top reference layer from bottom to top. The bottom reference layer, the barrier layer and the free layer form a tunneling structure; the free layer, the metal isolation layer and the top reference layer form a spin valve structure. According to the device, weak antiferromagnetic RKKY interaction is formed between the free layer and the top reference layer through the metal isolation layer, and the free layer and the top reference layer are reasonably designed, so that critical write-in currents of the free layer and the top reference layer meet specific conditions, and the device can be adaptively evolved into a magnetic structure with the minimum read error rate in the data write-in process; compared with a conventional external means, initialization configuration is independently carried out on the top reference layer before reading and writing operation, the complexity of an external circuit can be greatly reduced, and the power consumption of a complete operation period is reduced.

The application discloses a giant magnetoresistance (GMR) flaw detection sensor based on a micro-nano structure substrate and a preparation method thereof. The GMR flaw detection sensor comprises an excitation module and a pickup module. The pickup module comprises a micro-nano substrate. The surface of the micro-nano substrate is a micro-nano array structure. A spin valve film is deposited on the surface of the micro-nano array structure. The spin valve film is composed of ferromagnetic layers and non-magnetic layers which are alternately stacked. A fractal structure is formed on the surface of the spin valve film. The spin valve film is connected with a pickup electrode arranged on the surface of the micro-nano substrate. The pickup electrode is connected with an external detection circuit. The excitation module is a metal coil with the same fractal pattern as the fractal structure and is used for generating an excitation magnetic field. The application effectively changes a magnetic domain flipping mechanism, causes a magnetization process to occur gradually, thereby forming a multi-peak graded response on a resistance-magnetic field curve, and significantly improves the sensitivity and signal-to-noise ratio of the sensor.

The invention discloses a spin valve device and a preparation method and a detection method thereof. The invention provides an application of a cyclized indigo material as a non-magnetic intermediate layer in a spin valve device. The invention also provides a spin valve device using the cyclized indigo material as the non-magnetic intermediate layer, a preparation method of the spin valve device, and a detection method for the spin diffusion length of the non-magnetic intermediate layer in the spin valve device. The cyclized indigo blue material disclosed by the invention is used as a non-magnetic intermediate layer in a spin valve device, and shows a relatively long spin diffusion length and a relatively high magnetic resistance value MR at room temperature. In addition, the halogen-substituted cyclized indigo materials can enable the spin performance of the spin valve device to be rapidly improved. In addition, the invention also provides a method for detecting the spin diffusion length of the non-magnetic intermediate layer according to a plurality of magnetoresistance signals corresponding to the spin valve containing the non-magnetic intermediate layers with different thicknesses. The method has reliability.

The invention discloses a complementary spin valve device and a spin logic circuit. The complementary spin valve device comprises a positive spin valve and a negative spin valve; the structure of the positive spin valve sequentially comprises a top electrode, a semiconductor layer, an interface layer and a bottom electrode from top to bottom. The structure of the negative spin valve sequentially comprises a top electrode, an oxide layer, a semiconductor layer, an interface layer and a bottom electrode from top to bottom, and the top electrode and the bottom electrode in the positive spin valve and the negative spin valve are made of metal iron, cobalt, nickel or a mixture or alloy of any two or three of the metal iron, the cobalt and the nickel. The positive / negative spin valve device is obtained by accurately adjusting the oxide layer of the spin valve device, the complementary magnetic response of the positive / negative organic spin valve under the same magnetic field condition is ensured, and the blank of the complementary device based on electron spin transmission is filled. According to the spin logic gate, breakthrough high gain and high noise margin are achieved, the outstanding cycling stability is achieved, and a new path is created for development of storage and calculation integrated devices.

This invention discloses an epitaxial growth method for iron telluride thin films with controllable crystal phase structure and magnetic properties, belonging to the field of iron chalcogenide thin film preparation technology. This invention achieves the directional selective preparation of tetragonal and hexagonal FeTe thin films by precisely matching the substrate crystal symmetry with the growth temperature window. Compared to the limitations of existing CVD methods, which rely on specific precursors, generate harmful gases, and are difficult to prepare large-area epitaxial films, this invention features a simple process, requires no special precursors, has a highly controllable growth process, good repeatability, and produces thin films with high crystallinity, uniform composition, and controllable thickness. The two crystal phases have significantly different magnetic properties, providing a material selection for antiferromagnetic pinning layers and ferromagnetic storage media in spintronic devices, effectively promoting the research and application in low-dimensional magnetic devices, high-density magnetic storage, and spin valves.

The application provides a spin valve magnetic sensing array based on a Wheatstone bridge and a preparation method thereof. Based on the problem of poor linearity of a conventional spin valve magnetic sensor under a low magnetic field, the application introduces a Wheatstone bridge structure, utilizes a differential measurement and a signal amplification mechanism, and achieves the technical effect of effectively improving the linear response of the sensor in a low magnetic field range.

A magnetic tunnel junction (MTJ) is disclosed wherein a nitride diffusion barrier (NDB) has a L2 / L1 / NL or NL / L1 / L2 configuration wherein NL is a metal nitride or metal oxynitride layer, L2 blocks oxygen diffusion from an adjoining Hk enhancing layer, and L1 prevents nitrogen diffusion from NL to the free layer (FL) thereby enhancing magnetoresistive ratio and FL thermal stability, and minimizing resistance x area product for the MTJ. NL is the uppermost layer in a bottom spin valve configuration, or is formed on a seed layer in a top spin valve configuration such that L2 and L1 are always between NL and the FL or pinned layer, respectively. In other embodiments, one or both of L1 and L2 are partially oxidized. Moreover, either L2 or L1 may be omitted when the other of L1 and L2 is partially oxidized. A spacer between the FL and L2 is optional.

The invention discloses a ferromagnetic metal / two-dimensional ferromagnetic semimetal heterojunction-based spin electronic device, which comprises a ferromagnetic metal electrode and a single-layer two-dimensional ferromagnetic semimetal material layer, the ferromagnetic metal is nickel (Ni) or cobalt (Co), the two-dimensional ferromagnetic semimetal is ferrous halide FeX2, X is Cl, Br or I, and the thickness of the ferromagnetic metal electrode and the thickness of the two-dimensional ferromagnetic semimetal material layer are smaller than that of the ferromagnetic metal electrode. The two are in edge contact or top contact to form a heterojunction, and the spin injection efficiency close to 100% can be achieved; on the basis of a Ni and ferrous chloride (FeCl2) heterojunction structure, hexagonal boron nitride (h-BN) is introduced as a two-dimensional tunneling barrier layer, and a Ni / FeCl2 / h-BN / FeCl2 / Ni Van der Waals magnetic tunnel junction device can be constructed. According to the structure, the tunneling current of complete spin polarization is reserved in the parallel magnetization direction, the transmissivity is remarkably reduced in the anti-parallel magnetization direction, and the TMR (Tunnel Magnetoresistance) exceeding 3000% can be realized. Through the heterojunction structure and interface configuration design, the spin transport is effectively regulated and controlled on the device level, and the device is suitable for a spin valve, a spin filter and a low-power-consumption magnetic tunnel junction memory.

The invention discloses a spin valve device based on ferroelectric metal. The spin valve device comprises a top electrode, a first ferromagnetic layer, a ferroelectric metal layer, a second ferromagnetic layer and a bottom electrode which are sequentially stacked from top to bottom. Wherein the ferroelectric metal layer has ferroelectricity and metal conductivity at the same time, and is in direct contact with the upper ferromagnetic layer and the lower ferromagnetic layer to form an interface magnetoelectric coupling effect. Based on the core structure, the invention provides two nonvolatile memories, namely an STT type memory and an SOT type memory, the STT type memory performs writing by utilizing a spin-transfer torque effect, and the SOT type memory performs writing on a bottom heavy metal layer by utilizing a spin-orbit torque effect. Voltage pulses are applied to the ferroelectric metal layer to regulate and control the polarization state of the ferroelectric metal layer, so that magnetization overturning of the second ferromagnetic layer can be effectively assisted to reduce write-in power consumption; different polarization states of the ferroelectric metal layer are combined with different magnetization states of the ferromagnetic layer, so that a plurality of distinguishable resistance states can be formed, and multi-state information storage is realized.

The application belongs to the technical field of condensed matter physics and spintronics, and more particularly relates to CeSn 0.75 The application relates to the application of Sb2 single crystal material in magnetoresistance sensors and spin valve devices. The single crystal material has a significant angular magnetoresistance effect under an applied magnetic field, and the resistivity peak is strictly aligned with the high symmetry axis direction of the crystal, and is suitable for preparing high-sensitivity magnetoresistance sensors. Meanwhile, the magnetoresistance of the material under the hydrostatic pressure changes with the magnetic field intensity, and can realize the reversible high / low resistance state switching, and exhibits a natural spin valve giant magnetoresistance effect. The application breaks the dependence of traditional spin valve devices on ferromagnetic / non-magnetic complex multi-layer heterostructures, and only uses the intrinsic properties of a single material to realize high-sensitivity magnetoresistance state regulation, has the advantages of simple preparation process and flexible regulation means, and has important application value in the fields of novel single crystal spin electronic devices, small magnetic bias angle detection and high-density magnetic memory.

This invention discloses a spintronic device based on a ferromagnetic metal / two-dimensional ferromagnetic half-metal heterojunction, comprising a ferromagnetic metal electrode and a single-layer two-dimensional ferromagnetic half-metal material layer. The ferromagnetic metal is nickel (Ni) or cobalt (Co), and the two-dimensional ferromagnetic half-metal is ferrous halide FeX2, where X = Cl, Br, or I. The two electrodes can form a heterojunction through edge contact or top contact, achieving a spin injection efficiency close to 100%. Hexagonal boron nitride (FeCl2) is further introduced into the Ni and ferrous chloride (FeCl2) heterojunction structure. h Ni / FeCl2 / BN can be used as a two-dimensional tunneling barrier layer to construct Ni / FeCl2 / h A van der Waals magnetic tunnel junction device based on -BN / FeCl2 / Ni. This structure retains fully spin-polarized tunneling current in the parallel magnetization direction and significantly reduces transmittance in the antiparallel magnetization direction, achieving a tunnel magnetoresistance (TMR) exceeding 3000%. This invention achieves effective control of spin transport at the device level through heterojunction structure and interface configuration design, and is suitable for spin valves, spin filters, and low-power magnetic tunnel junction memories.

The application discloses a nanocrystal antiferromagnetic material, a preparation method and application, and the material is a cobalt-nickel-silicon (Co-Ni-Si) ternary polycrystal material, the chemical composition of which is composed of three elements of cobalt (Co), nickel (Ni) and silicon (Si), and the atomic number ratio of the cobalt, the nickel and the silicon is (33+ / -1):(21+ / -1):(46+ / -1). The preparation method comprises the following steps: (1) dosing; (2) packaging; (3) chemical vapor transport reaction; and (4) sampling. The antiferromagnetic material has wide application in preparation of spin electronic devices, such as magnetic tunnel junctions, spin valves, magnetic random access memories and magnetic sensors; and the material is used as an antiferromagnetic pinning layer, a reference layer or an active layer based on antiferromagnetism in the spin electronic devices.