7 results about "Ferromagnetic thin films" patented technology

A quantum frequency converter includes a laminate including at least one topological insulator film and at least one ferromagnetic film that are laminated together. The laminate includes an interface between the topological insulator film and the ferromagnetic film and configured to be irradiated with laser light. The quantum frequency converter includes a magnetic field applying unit configured to apply a magnetic field with a component perpendicular to the interface to the laminate, and a microwave transceiver configured to transmit and receive a microwave to and from the laminate.

The invention discloses a voltage regulation and control magnetic memory based on a two-dimensional ferromagnetic / multiferroic heterostructure and a preparation method, the device is composed of a substrate, a multiferroic thin film layer, a two-dimensional ferromagnetic thin film layer, an upper electrode and a lower electrode, an uncompensated magnetic moment is generated on an interface through ferroelectric polarization of the multiferroic layer, and the uncompensated magnetic moment and the two-dimensional ferromagnetic layer form exchange bias. And the ferroelectric polarization direction can be reversed by applying low voltage, so that the external magnetic field-free and nonvolatile regulation and control of the magnetization of the two-dimensional ferromagnetic layer are realized. The preparation method comprises the steps of magnetron sputtering growth of the multiferroic thin film, interface annealing treatment, molecular beam epitaxial growth of the two-dimensional ferromagnetic thin film and electrode preparation. The device has strong interface coupling, low power consumption, high regulation and control amplitude and good cycling stability at room temperature, wide-range voltage regulation and control of exchange bias can be realized, and a reliable technical scheme is provided for a novel low-power-consumption nonvolatile memory.

The present disclosure relates to a magnetic tunnel junction with double fixed layers, a magnetic memory chip, and a manufacturing method thereof. The present disclosure provides a magnetic tunnel junction with double fixed layers, a magnetic memory chip, and a manufacturing method thereof, including a structure of a bottom fixed layer formed by three layers of ferromagnetic thin film structures coupled in an anti-parallel manner, and then, from the perspective of the coupling magnetic field of the bottom fixed layer to the free layer, a thickness and a material of each layer of the ferromagnetic thin film structure of the above-mentioned structure are provided, and, on the basis of the bottom fixed layer, a structure of the top fixed layer is further provided. The present disclosure provides a magnetic tunnel junction with double fixed layers, a magnetic memory chip, and a manufacturing method thereof.

This invention belongs to the field of quantum sensors and discloses a diamond spin quantum sensor and its fabrication method. The fabrication method includes: cleaning and polishing a single-crystal diamond substrate; and preparing a nitrogen-vacancy color center with a density greater than 10 on the single-crystal diamond substrate using microwave plasma chemical vapor deposition. 16 cm ‑3 A diamond spin quantum sensor was obtained by fabricating an antiferromagnetic NiO thin film on a diamond film using radio frequency magnetron sputtering. This invention comprises a diamond thin film with a high concentration of nitrogen-vacancy centers. Nitrogen-vacancy center measurements exhibit extremely high spatial resolution and can detect nanoscale magnetic field changes. The diamond spin quantum sensor is applied to the precise measurement of the magnetic moment of antiferromagnetic thin films and the magnetic coupling effect at the interface of antiferromagnetic / ferromagnetic heterojunctions. Furthermore, its fabrication method is simple and economical, providing a possibility for the application of diamond nitrogen-vacancy center materials in the field of quantum magnetic sensors.

A kind of test system, method and magneto-optical kerr effect criterion method of high-order magneto-optical kerr effect in ferromagnetic film belong to the field of spintronics and magneto-optics. By building a magneto-optical kerr detection light path, the direction of the external magnetic field is regulated by the quadrupole magnet to regulate the magnetic moment direction of the sample, and the light intensity change curve under the rotating magnetic field is detected by the photodetector. Whether the sample has second-order magneto-optical kerr effect (QMOKE) is characterized, and the intensity is quantitatively observed. The method only needs a single light intensity change curve obtained by vertical incidence as the characterization basis of QMOKE, and the measurement method of small step (5°) rotation of external magnetic field comprehensively characterizes the influence of magnetic field direction on QMOKE signal, and can calculate QMOKE intensity according to amplitude, simplifies the steps of separating first-order magneto-optical kerr effect (LMOKE) and QMOKE, and simplifies the characterization criterion of QMOKE effect of ferromagnetic film system, especially Fe structure film.

The present invention relates to the field of magnetic memory chips in integrated circuits, and in particular to a dual-pinned magnetic tunnel junction, a magnetic memory chip and manufacturing methods therefor. The present invention provides a dual-pinned magnetic tunnel junction, a magnetic memory chip and manufacturing methods therefor. The dual-pinned magnetic tunnel junction comprises a structure in which a bottom pin layer is formed by three ferromagnetic thin film structure layers by means of anti-parallel coupling. Then, the thickness and material of each ferromagnetic thin film structure layer of the structure are provided from the perspective of a coupling magnetic field from the bottom pin layer to a free layer, and the structure of a top pin layer is further provided on the basis of the bottom pin layer. The present invention provides manufacturing methods for a dual-pinned magnetic tunnel junction and a magnetic memory chip. The present invention greatly reduces the energy consumption for writing information into STT-MTJ-based MRAM chips, greatly increases the durability of the STT-MTJ-based MRAM chips, and achieves the large-scale application of MRAMs as replacements for DRAMs and SRAMs.

The application discloses a temperature sensor assembly, a temperature measuring method and system, and is based on a ferromagnetic film. The physical characteristics that the temperature has a relevant influence on the size of an abnormal Hall coefficient or a vertical magnetization intensity are utilized to prepare the micron size level temperature sensor device. The corresponding relationship curve between the abnormal Hall resistance difference and the temperature is established by measuring the change curve of the abnormal Hall resistance value and the vertical magnetic field size under different external temperatures. The polynomial fitting degree of the curve is high, the deviation between the test result and the fitting curve is small, and therefore the efficient measurement of the temperature in a wide measuring temperature range of 100K to 490K can be realized. Performance evaluation shows that the above-mentioned thin film structure has good vertical magnetic anisotropy, and the temperature sensor has good repeated test performance, temperature measuring durability, high temperature measuring precision and wide temperature measuring range.