5879results about "Magnetic-field-controlled resistors" patented technology

A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.

A magnetic switching device, includes a first electrode, a second electrode, and a nanoparticle having a magnetic moment and being disposed between the first and second electrodes. At least one of the first electrode and the second electrode includes a magnetic material which has a net spin polarization in its conduction band for injecting, into the nanoparticle, an electrical current including a net spin polarization for overcoming the magnetic moment of the nanoparticle upon selection of a predetermined magnitude for the electrical current.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer 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 magnetic element may also include a barrier layer, a second pinned layer. Alternatively, second pinned and second spacer layers and a second free layer magnetostatically coupled to the free layer are included. At least one free layer has a high perpendicular anisotropy. The high perpendicular anisotropy has a perpendicular anisotropy energy that is at least twenty and less than one hundred percent of the out-of-plane demagnetization energy.

A method and system for providing a magnetic element capable of storing multiple bits is disclosed. The method and system include providing first pinned layer, a first nonmagnetic layer, a first free layer, a connecting layer, a second pinned layer, a second nonmagetic layer and a second free layer. The first pinned layer is ferromagnetic and has a first pinned layer magnetization pinned in a first direction. The first nonmagnetic layer resides between the first pinned layer and the first free layer. The first free layer being ferromagnetic and has a first free layer magnetization. The second pinned layer is ferromagnetic and has a second pinned layer magnetization pinned in a second direction. The connecting layer resides between the second pinned layer and the first free layer. The second nonmagnetic layer resides between the second pinned layer and the second free layer. The second free layer being ferromagnetic and having a second free layer magnetization. The magnetic element is configured to allow the first free layer magnetization and the second free layer magnetization to change direction due to spin transfer when a write current is passed through the magnetic element.

A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The method and system include providing a first pinned layer, a barrier layer, a free layer, a conductive nonmagnetic spacer layer, and a second pinned layer. Each pinned layer has a pinned layer easy axis. At least a portion of the pinned layer easy axis is in a perpendicular direction. The barrier layer resides between the first pinned layer and the free layer. The spacer layer is between the free layer and the second pinned layer. The free layer has a free layer easy axis, at least a portion of which is in the perpendicular direction. The magnetic element is also configured to allow the free layer to be switched due to spin transfer effect when a write current is passed through the magnetic element. Because of the perpendicular magnetization(s), the writing current for spin transfer may be significantly reduced.

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.

Magnetic tunnel junction magnetic device (16) for writing and reading uses a reference layer (20c) and a storage layer (20a) separated by a semiconductor or insulating layer (20b). The blocking temperature of the magnetisation of the storage layer is less than that of the reference layer. The storage layer is heated (22, 24) above the blocking temperature of its magnetisation. A magnetic field (34) is applied (26) to it orientating its magnetization with respect to that of the reference layer without modifying the orientation of the reference layer.

The present invention generally relates to the field of magnetic devices for memory cells that can serve as non-volatile memory. More specifically, the present invention describes a high speed and low power method by which a spin polarized electrical current can be used to control and switch the magnetization direction of a magnetic region in such a device. The magnetic device comprises a pinned magnetic layer with a fixed magnetization direction, a free magnetic layer with a free magnetization direction, and a read-out magnetic layer with a fixed magnetization direction. The pinned magnetic layer and the free magnetic layer are separated by a non-magnetic layer, and the free magnetic layer and the read-out magnetic layer are separated by another non-magnetic layer. The magnetization directions of the pinned and free layers generally do not point along the same axis. The non-magnetic layers minimize the magnetic interaction between the magnetic layers. A current is applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to thereby read out the information stored in the device.

Use of a multilayer etching mask that includes a stud mask and a removable spacer sleeve for MTJ etching to form a bottom electrode that is wider than the rest of the MTJ pillar is described. The first embodiment of the invention described includes a top electrode and a stud mask. In the second and third embodiments the stud mask is a conductive material and also serves as the top electrode. In embodiments after the stud mask is formed a spacer sleeve is formed around it to initially increase the masking width for a phase of etching. The spacer is removed for further etching, to create step structures that are progressively transferred down into the layers forming the MTJ pillar. In one embodiment the spacer sleeve is formed by net polymer deposition during an etching phase.

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 logic cell includes a magnetic element having a pinned layer, a free layer, and a spacer layer. The pinned and free layers have pinned and free layer magnetizations. The spacer layer resides between the pinned and free layers. In one aspect, the magnetic logic cell includes a first configuration line that is electrically connected to the magnetic element and carries a first current and a second configuration line electrically that is insulated from the magnetic element and the first configuration line and carries a second current. The first or second current alone cannot switch the free layer magnetization. The first and second currents together can switch the free layer magnetization. When the first current is driven through the magnetic element and the second current is provided, the combination sets the pinned layer magnetization direction. In one aspect, the pinned layer magnetization is set by heating the AFM layer to approximately at or above the blocking temperature. In order to configure the logic cell, an initial direction for the free layer magnetization is also set.

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 method and structure for a non-volatile magnetic random access memory (MRAM) device that has a stable magnetic electrode, an oxide layer adjacent the stable magnetic electrode, and a free magnetic electrode. The oxide layer is between the stable magnetic electrode and the free magnetic electrode. In the invention, a conductor is connected to a stable magnetic electrode. The oxide layer has a resistance at levels to allow sufficient power dissipation to lower the anisotropy of the free magnetic electrode through current induced heating. Current-induced heating is used in combination with spin-transfer torque or a magnetic field to switch the free magnetic electrode.

A method and system for providing a magnetic memory is disclosed. The method and system include providing a plurality of magnetic elements and providing at least one stress-assist layer. Each of the plurality of magnetic elements is configured to be written using spin transfer. The at least one stress-assist layer is configured to exert at least one stress on at least one magnetic element of the plurality of magnetic elements during writing. The reduction of spin-transfer switching current is due to stress exerted by the stress-assist layer on the magnetic elements during writing. Stability of the magnetic memory with respect to thermal fluctuations is not compromised because the energy barrier between the two magnetization states is unchanged once the switching current is turned off.