37 results about "Spin valve" patented technology

The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a first sensor disposed at a media facing surface (MFS) comprising at least one free layer, a second sensor disposed at the MFS comprising at least one free layer, a first spin generator spaced from the first sensor and recessed from the MFS, and a second spin generator spaced from the second sensor and recessed from the MFS. The first and second spin generators each individually comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise BiSb. The first and second sensors are configured to detect a read signal using a first voltage lead and a second voltage lead. The first and second spin generators are configured to inject spin current through non-magnetic layers to the first and second sensors using a plurality of current leads.

According to an embodiment of the inventive concept, a magnetic memory device includes a substrate on which a transistor controlled by a word line is disposed, a spin detection layer disposed on the substrate, and a magnon spin valve disposed on the spin detection layer. Here, the magnon spin valve includes a free layer disposed on the spin detection layer, a reference layer disposed on the free layer, and a spacer disposed between the free layer and the reference layer. Also, one edge of the spin detection layer is connected to a source / drain region of the transistor, the other edge of the spin detection layer is connected to a source line, and the magnon spin valve is disposed on a portion between the one edge and the other edge of the spin detection layer. The spin detection layer includes a topological material or a weyl semimetal. Each of the reference layer and the free layer includes a ferromagnetic insulator.

The present disclosure generally relates to a magnetic recording head comprising a read head. The read head comprises a sensor disposed at a media facing surface (MFS) and a spin generator spaced from the sensor and recessed from the MFS. The sensor and spin generators are disposed on a non-magnetic layer. The sensor comprises a free layer and the spin generator comprises at least one spin orbit torque (SOT) layer. The SOT layer may comprise topological material such as BiSb. The sensor is configured to detect a read signal using a first voltage lead and a second voltage lead. The spin generator is configured to inject spin current through the non-magnetic layer to the sensor using a first current lead and a second current lead. The shape of the non-magnetic layer is a triangular or trapezoidal shape to further concentrate spin current.

To provide a magnetic recording head including a read head with high signal output for use in a magnetic recording device.SOLUTION: A read head 500 includes a sensor 540 disposed on a media facing surface (MFS) and a spin generator 550 disposed away from the sensor and recessed from the MFS. The sensor and the spin generator are disposed on a non-magnetic layer 406. The sensor includes a free layer, and the spin generator includes at least one spin-orbit-torque (SOT) layer 510. The SOT layer is configured from a topological material such as BiSb. The sensor detects a read signal by using a first voltage lead line V+ and a second voltage lead line V-. The spin generator is configured to inject a spin current into the sensor via the non-magnetic layer by using a first current lead line I+ and a second current lead line I-. The shape of the non-magnetic layer is triangular or trapezoidal to further concentrate the spin current.SELECTED DRAWING: Figure 5A-5B

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 relates to a method for improving spin injection efficiency by using a buffer layer, relating to spintronics. A long strip-shaped single-layer graphene is prepared on a silicon substrate, a double-layer h-BN is prepared and transferred onto the single-layer graphene as a tunneling layer, PMMA is spin-coated, a ferromagnetic electrode shape is exposed by using an EBL system, and development is carried out after the exposure is completed; the sample is placed into an electron beam / thermal evaporation composite plating film system, a low-melting-point metal indium is pre-evaporated as a buffer layer by using a thermal evaporation method, cobalt is electron beam evaporated as a ferromagnetic electrode, an In / Co miscible alloy interface is formed by annealing at 200 DEG C under an argon atmosphere for 1 h, and a spin valve device with a buffer layer is obtained. The method forms a lossless interface of a ferromagnetic electrode layer-buffer layer-tunneling layer, and spin injection efficiency is improved. The method is easy to realize, low in cost, low in operation difficulty and technical requirement, and beneficial to large-scale industrial application; the method is very good in universality, and can be popularized to other spin electronic devices with a tunneling layer to improve the spin injection efficiency of the devices.

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.

A spin valve device (400) comprising a layer stack one or more layers (106; 107; 108; 109; 110) that form a unidirectionally magnetized reference frame; a vortex-magnetized free layer (102); a non-magnetic layer (104) that separates the reference frame from the free layer (102); and one or more layers forming a prestressing structure (402) which is exchange-coupled with the free layer (102), wherein the prestressing structure has a vortex magnetization with closed flux of a predetermined rotational direction.

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.

A semiconductor device and a manufacturing method therefor. The semiconductor device comprises: a magnetic material layer, comprising a magnetic tunnel junction or a magnetic spin valve; a first electrode, directly or indirectly arranged on a first surface of the magnetic material layer; a second electrode, directly or indirectly arranged on a second surface opposite to the first surface of the magnetic material layer; and a first stress layer, covering the side wall of an integral structure formed by at least the magnetic material layer, the first electrode and the second electrode, wherein the first stress layer is an insulating stress layer. According to the semiconductor device and the manufacturing method therefor, the technical problem of having difficulty in maintaining relatively stable stress when scaling of semiconductor devices is carried out is solved, and the performance and stability of key parameters of semiconductor devices are improved.

The invention discloses a medium entropy alloy material with zero-field cold exchange bias effect and a preparation method thereof. The chemical formula of the material is Mn 2‑x FeCoNi, 0.2≤x≤0.4, firstly obtain Mn by repeated smelting 2‑x The FeCoNi alloy is then sealed in a vacuum quartz tube and placed in a muffle furnace for annealing. 2‑ x The FeCoNi medium-entropy alloy material has a zero-field cold exchange bias effect. The size of its ferromagnetic and antiferromagnetic exchange coupling can be controlled by changing the Mn composition (0.2≤x≤0.4) to obtain a specific antiferromagnetic and ferromagnetic coupling ratio, thereby obtaining an obvious zero-field cold exchange bias field without the need for an additional external magnetic field accompanying the cooling process. This material has potential application prospects in spin electronics fields such as magnetic storage units and spin valve devices.

The invention discloses a nanocrystal antiferromagnetic material, a preparation method and application, the nanocrystal antiferromagnetic material is a cobalt-nickel-silicon (Co-Ni-Si) ternary polycrystalline material, the chemical components of the nanocrystal antiferromagnetic material comprise three elements of cobalt (Co), nickel (Ni) and silicon (Si), and the atomic number ratio of cobalt to nickel to silicon is (33 + / -1): (21 + / -1): (46 + / -1). The preparation method comprises the following steps: (1) burdening; (2) packaging; (3) chemical vapor transport reaction; and (4) sampling. The antiferromagnetic material is widely applied to preparation of spintronics devices, such as magnetic tunnel junctions, spin valves, magnetic random access memories and magnetic sensors; the material is used as an antiferromagnetic pinning layer, a reference layer or an antiferromagnetic-based active layer in spintronics devices.

The present invention discloses a shear strain-controlled CrS2 spin valve device, which is formed by parallel connection of two or more spin valve device units. Each spin valve device unit includes a substrate, a CrS2 layer and a protective layer disposed on the substrate, and is prepared by the following method: First, a 1T'-phase CrS2 layer is grown on the substrate; Second, a lateral heterojunction is regulated and formed; Third, a protective layer is grown on the lateral heterojunction; Fourth, a magnetic heterojunction is regulated and formed; The present invention also discloses a control method for the spin valve device unit: after connecting the spin valve device to an external circuit, a shear strain is applied to adjust the spin state of the spin valve device unit. Based on the ferroelasticity of CrS2 itself and the mutual coupling of ferromagnetism and ferroelasticity, the ferroelasticity of the 1T'-phase CrS2 layer is regulated by strain to further adjust its magnetic transition, solving the problem of matching different materials with different properties; the control method of the present invention is simple and easy to implement.

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 present invention belongs to the field of magnetic sensing technology, and specifically relates to a spin-valve type giant magnetoresistive linear sensor based on the interlayer DMI field. The present invention proposes a new structure of a spin-valve type giant magnetoresistive sensing unit. By introducing the interlayer DMI field into the spin-valve type giant magnetoresistive sensing unit during preparation, the magnetic moment of ferromagnetic layer 2 is along the short axis direction by the action of the interlayer DMI field on ferromagnetic layer 1; while the magnetic moment of ferromagnetic layer 3 is not affected by the action of this interlayer DMI field, and its magnetic moment still aligns along the long axis of the unit; thereby realizing that the magnetic moments of the free layer and the fixed layer of the spin-valve type giant magnetoresistive linear sensing unit are perpendicular to each other under zero field after plating, meeting the requirements of linear sensing. The present invention combines the DMI field in the field of spintronics with the giant magnetoresistive effect, which can be completed in one step during preparation, without any additional processes and external magnetic field bias settings, reducing the manufacturing cost and difficulty, and greatly ensuring the simplicity of preparation and the stability of the sensing unit.

A Josephson magnetic memory cell having a semiconductor-based magnetic spin valve is described. The example memory cell includes a first superconducting electrode, a second superconducting electrode, and a semiconductor-based magnetic spin valve disposed between the two superconducting electrodes. The semiconductor-based magnetic spin valve includes a semiconductor layer and a first ferromagnetic insulator disposed adjacent to the semiconductor layer, disposed on a first side of the semiconductor layer, and configured to provide a fixed magnetization oriented in a first direction. The semiconductor-based magnetic spin valve also includes a second ferromagnetic insulator disposed on a second side of the semiconductor layer, opposite the first side, and configured to provide a free magnetization oriented in the first direction or in a second direction opposite the first direction, so as to control a parameter associated with the flow of current from the first superconducting electrode, through the semiconductor layer, and to the second superconducting electrode.

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.

A spin wave logic device and related circuits. The spin wave logic device includes a channel, and a drain and source located above the channel. The source is used to generate a spin wave signal. The channel is used to transmit the spin wave signal to the drain. The drain includes a magnetic tunnel junction or a spin valve structure, and is used to exhibit different resistance states based on the spin wave signal, wherein the different resistance states are used to indicate different logical values. The spin wave logic device can detect magnon signals through tunneling magnetoresistance or giant magnetoresistance, preventing information loss after power failure and achieving effective storage of magnon information.

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 present invention discloses a method for preparing a flexible spin valve, belonging to the field of magnetoelectronics. The method utilizes PI as a carrier, magnetic particles or diamagnetic particles as dopants, and a laser-induced graphene process to layer-by-layer prepare flexible ferromagnetic or antiferromagnetic thin films, thereby constructing a flexible spin valve device. Because the prepared thin films are all made of flexible materials, their bending resistance is significantly improved. This method allows for the large-scale production of spin valves, providing a new approach to the preparation of magnetic electronic devices.

The invention provides a method for calculating the electron transport property of a metal phthalocyanine molecular device, and relates to the technical field of organic electronics and computational material scientifes.The method comprises the steps of molecular structure construction, electronic ground state analysis and quantum transport simulation.According to the method, a TiPC device shows a sharp formant near the Fermi energy level under the zero bias, the transmission intensity is the highest, and the electron transport property of the metal phthalocyanine molecular device is calculated. The current density reaches # imgabs0 # and is 2 orders of magnitude higher than that of a traditional semiconductor device, the semiconductor device is suitable for high-speed low-power-consumption electronic devices, ScPC and CuPC are high in state density near the Fermi level, a strong coupling resonance channel is formed, the transport efficiency is remarkably superior to that of a non-magnetic system, d-track occupied state reconstruction occurs under electric field driving of a CrPC device, room temperature negative differential resistance is induced, and the performance of the semiconductor device is improved. The method can be applied to high-frequency oscillation and signal amplification. The spin polarizability of the FePC device reaches 65%, the spin upward and downward channel state densities are obviously asymmetric, and the method is suitable for spin electronic devices such as a spin valve and a spin filter.

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 application discloses a magnetic memory, which comprises a magnetic spin valve, a coupling layer and a magnetic tunnel junction from top to bottom; the magnetic spin valve comprises a spin reference layer, a non-magnetic spacer layer and a spin free layer from top to bottom; the magnetic tunnel junction comprises a tunnel free layer, a barrier layer and a tunnel reference layer from top to bottom; the magnetic tunnel junction is magnetically coupled with the magnetic spin valve through the coupling layer. The magnetic spin valve of the application provides an additional spin transfer torque for the magnetic memory, greatly improves the STT efficiency, drives the magnetic memory to flip using a smaller current, and further significantly reduces the power consumption of the magnetic memory. In addition, the magnetic spin valve has a smaller influence on the tunnel magnetoresistance of the whole device, so that the device can still maintain a high tunnel magnetoresistance. The application also provides an electronic device with the above beneficial effects.

A memory cell having a Josephson junction and a magnetic junction in close proximity. The two junctions may be vertically integrated. The magnetic junction has at least two magnetic layers with different coercive forces and a non-magnetic layer therebetween, to form a spin valve or pseudo-spin valve. A magnetization direction of a magnetic layer with lower coercive force can be rotated with respect to the larger coercive force magnetic layer(s). Magnetic fields produced by appropriately configured control lines carrying electric current, or spin-polarized current through the magnetic junction, can result in rotation. The magnetic junction influences the Josephson critical current of the Josephson junction, leading to distinct values of critical current which can serve as digital logic states. The memory cell can be integrated into large arrays containing a plurality of the cells, to enable the selective READ and WRITE operations.

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.