5758results about "Magnetic-field-controlled resistors" patented technology

The present invention is directed to a machine with a position feedback system and a method for use thereof. The machine includes at least one movable element mounted for movement on a path and at least one programmable controller. The machine further includes at least two absolute or magnetostrictive sensors or the machine includes an absolute sensor and a non-absolute sensor. The programmable controller uses positional information from the sensors to determine the position of the movable elements on the path and control the movable elements. The method includes determining a known position for the movable elements, linking at least two magnetostrictive sensors into one virtual sensor, and/or performing commutation alignment for the movable elements. Determining the position and commutation alignment can occur when the movable elements are stationary or moving.

A magnetic memory device for reading and writing a data state comprises at least three terminals including first, second, and third terminals. The magnetic memory device also includes a spin transfer (ST) driven element, disposed between the first terminal and the second terminal, and a readout element, disposed between the second terminal and the third terminal. The ST driven element includes a first free layer, and a readout element includes a second free layer. A magnetization direction of the second free layer in the readout element indicates a data state. A magnetization reversal of the first free layer within the ST driven element magnetostatically causes a magnetization reversal of the second free layer in the readout element, thereby recording the data state.

A magnetic element that can be used in a memory array having high density includes a pinned layer, a half-metallic material layer, a spacer (or a barrier) layer and a free layer. The half-metallic material layer is formed on the pinned layer and preferably has a thickness that is less than about 100 Å. The half-metallic material layer can be formed to be a continuous layer or a discontinuous on the pinned layer. The spacer (or barrier) layer is formed on the half-metallic material layer, such that the spacer (or barrier) layer is nonmagnetic and conductive (or insulating). The free layer is formed on the spacer (or barrier) layer and has a second magnetization that changes direction based on the spin-transfer effect when a write current passes through the magnetic element.

A method and system for providing a magnetic element capable of being written using spin-transfer effect while being thermally stable and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first, second and third pinned layers, first and second nonmagnetic layers, a free layer and a nonmagnetic spacer layers. The first, second and third pinned layers are ferromagnetic and have first, second and third magnetizations pinned in first, second and third directions. The first and second nonmagnetic layers include first and second diffusion barriers, respectively. The first and second nonmagnetic layers are between the first and second pinned layers and the second and third pinned layers, respectively. The first and second pinned layers and the second and third pinned layers are antiferromagnetically coupled. The nonmagnetic spacer layer is conductive and resides between the free layer and the third pinned layer. In addition, performance can be further improved by doping Co containing ferromagnetic layers with Cr and/or Pt.

A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0≧Ms<√{square root over ( )}{Jw/(6nAt)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.

A RRAM memory cell is formed on a silicon substrate having a operative junction therein and a metal plug formed thereon, includes a first oxidation resistive layer; a first refractory metal layer; a CMR layer; a second refractory metal layer; and a second oxidation resistive layer. A method of fabricating a multi-layer electrode RRAM memory cell includes preparing a silicon substrate; forming a junction in the substrate taken from the group of junctions consisting of N+ junctions and P+ junctions; depositing a metal plug on the junction; depositing a first oxidation resistant layer on the metal plug; depositing a first refractory metal layer on the first oxidation resistant layer; depositing a CMR layer on the first refractory metal layer; depositing a second refractory metal layer on the CMR layer; depositing a second oxidation resistant layer on the second refractory metal layer; and completing the RRAM memory cell.

A spin-torque transfer memory random access memory (STTMRAM) element includes a fixed layer formed on top of a substrate and a a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer and made of an iron platinum alloy with at least one of X or Y material, X being from a group consisting of: boron (B), phosphorous (P), carbon (C), and nitride (N) and Y being from a group consisting of: tantalum (Ta), titanium (Ti), niobium (Nb), zirconium (Zr), tungsten (W), silicon (Si), copper (Cu), silver (Ag), aluminum (Al), chromium (Cr), tin (Sn), lead (Pb), antimony (Sb), hafnium (Hf) and bismuth (Bi), molybdenum (Mo) or rhodium (Ru), the magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate.

The present invention relates to a magnetic thin film memory having a hybrid element including a field effect transistor and a magnetoresistive thin film connected to the field effect transistor in parallel. In the magnetic thin film memory, the hybrid element is preferably arranged in plurality in a matrix state. The present invention also relates to a method of writing information in this magnetic thin film memory, and a method of reading the information written in this magnetic thin film memory.

A magnetic element is disclosed that has a composite free layer with a FM1/moment diluting/FM2 configuration wherein FM1 and FM2 are magnetic layers made of one or more of Co, Fe, Ni, and B and the moment diluting layer is used to reduce the perpendicular demagnetizing field. As a result, lower resistance x area product and higher thermal stability are realized when perpendicular surface anisotropy dominates shape anisotropy to give a magnetization perpendicular to the planes of the FM1, FM2 layers. The moment diluting layer may be a non-magnetic metal like Ta or a CoFe alloy with a doped non-magnetic metal. A perpendicular Hk enhancing layer interfaces with the FM2 layer and may be an oxide to increase the perpendicular anisotropy field in the FM2 layer. The magnetic element may be part of a spintronic device or serve as a propagation medium in a domain wall motion device.

A magnetoresistive includes a first magnetic reference layer having a fixed magnetization direction, a magnetic free layer having a magnetization direction which is changeable by being supplied with spin polarized electrons, a second magnetic reference layer having a fixed magnetization direction, a first intermediate layer provided between the first magnetic reference layer and the magnetic free layer, and a second intermediate layer provided between the magnetic free layer and the second magnetic reference layer. The magnetic free layer and the first magnetic reference layer have directions of easy magnetization perpendicular or parallel to an in-plane direction. The first magnetic reference layer and the second magnetic reference layer have directions of easy magnetization perpendicular to each other.

A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.

A method and system for providing a magnetoresistive sensor is disclosed. The method and system include providing a first pinned layer, providing a free layer having a length, and providing a first spacer layer disposed between the first pinned layer and the free layer. The first spacer layer has a first interface with the first pinned layer. The method and system also include providing a second pinned layer and providing a second spacer layer disposed between the free layer and the second pinned layer. The second spacer layer has a second interface with the second pinned layer. A direction of a current passed through the magnetoresistive sensor is through the first interface, through the second interface, and along at least a portion of the length of the free layer.

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 magnetic element is disclosed wherein first and second interfaces of a free layer with a Hk enhancing layer and tunnel barrier, respectively, produce enhanced surface perpendicular anisotropy to lower switching current or increase thermal stability in a magnetic tunnel junction (MTJ). In a MTJ with a bottom spin valve configuration where the Hk enhancing layer is an oxide, the capping layer contacting the Hk enhancing layer is selected to have a free energy of oxide formation substantially greater than that of the oxide. The free layer may be a single layer or composite comprised of an Fe rich alloy such as Co₂₀Fe₆₀B₂₀. With a thin free layer, the interfacial perpendicular anisotropy may dominate the shape anisotropy to generate a magnetization perpendicular to the planes of the layers. The magnetic element may be part of a spintronic device or serve as a propagation medium in a domain wall motion device.

We describe the structure and method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co₆₀Fe₂₀B₂₀. of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.