Nve Corporation

Nonvolatile Electronics, Incorporated

Honeywell G.m.b.h.

United States of America As Represented by the Secretary of the Air Force

James M Daughton

Arthur V Pohm

Dexin Wang

Mark Christopher Tondra

Brenda Anne Everitt

John K Myers

James G Deak

Robert T Fayfield

Theodore M Hermann

Zhenghong Qian

John F Stokes

Thomas E Hendrickson

Allan T Hurst, Jr

Jack S Huang

Mona M Abdelrahman

Per N Forssell

Brenda A Everitt

A ferromagnetic thin-film based digital memory having a plurality of bit structures interconnected with manipulation circuitry having a plurality of transistors so that each bit structure has transistors electrically coupled thereto that selectively substantially prevents current in at least one direction along a current path through that bit structure and permits selecting a direction of current flow through the bit structure if current is permitted to be established therein. A bit structure has a nonmagnetic intermediate layer with two major surfaces on opposite sides thereof and a memory film of an anisotropic ferromagnetic material on each of the intermediate layer major surfaces with an electrically insulative intermediate layer is provided on the memory film on which a magnetization reference layer is provided having a fixed magnetization direction.

Circuit selection of magnetic memory cells and related cell structures

A current determiner comprising a first input conductor and a first current sensor, formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween, and both supported on a first side of a substrate adjacent to but electrically isolated from one another with the first current sensor positioned in those magnetic fields arising from any input currents. A first shield/concentrator of a material exhibiting a substantial magnetic permeability is positioned on a second side of the substrate opposite the first side of the substrate. The substrate can include a monolithic integrated circuit structure containing electronic circuit components of which at least one is electrically connected to the first input conductor.

Inverted magnetic isolator

A ferromagnetic thin-film based digital memory cell with a memory film of an anisotropic ferromagnetic material and with a source layer positioned on one side thereof so that a majority of conduction electrons passing therefrom have a selected spin orientation to be capable of reorienting the magnetization of the film. A disruption layer is positioned on the other side of the memory film so that conduction electrons spins passing therefrom are substantially random in orientation. The magnitude of currents needed to operate the cell can be reduced using coincident thermal pulses to raise the cell temperature.

Current switched magnetoresistive memory cell

A current determiner comprising a first input conductor and a first current sensor, formed of a p.lurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween, and both supported on a substrate adjacent to but electrically isolated from one another with the first current sensor positioned in those magnetic fields arising from any input currents. A first shield/concentrator of a material exhibiting a substantial magnetic permeability is positioned between the substrate and the first input conductor. The substrate can include a monolithic integrated circuit structure containing electronic circuit components of which at least one is electrically connected to the first input conductor. Magnetically permeable material can be provided in supporting structures.

A ferromagnetic thin-film based digital memory having bit structures therein with a magnetic material film in which a magnetic property thereof is maintained below a critical temperature above which such magnetic property is not maintained, and may also have a plurality of word line structures each with heating sections located across from the magnetic material film in a corresponding one of the bit structures. These bit structures are sufficiently thermally isolated to allow selected currents in the adjacent word lines or in the bit structure, or both, to selectively heat the bit structure to approach the critical temperature. Such bit structures may have three magnetic material layers each with its own critical temperature for maintaining versus not maintaining a magnetic property thereof.

Magnetic memory layers thermal pulse transitions

A ferromagnetic thin-film based magnetic field sensor having an electrically insulative intermediate layer with two major surfaces on opposite sides thereof with an initial film of an anisotropic ferromagnetic material on one of those intermediate layer major surfaces and thin-film platelets on the remaining one of the intermediate layer major surfaces.

Superparamagnetic platelets field sensing devices

A current determiner comprising a first input conductor and a first current sensor, formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween, and both supported on a substrate adjacent to and spaced apart from one another so they are electrically isolated with the first current sensor positioned in those magnetic fields arising from any input currents. A first shield/concentrator of a material exhibiting a substantial magnetic permeability is positioned between the substrate and the first input conductor. A similar second current sensor can be individually formed, but can also be in the current determiner structure that is supported on the substrate along with a second input conductor supported on the substrate suited for conducting input currents therethrough.

A tamper detecting enclosure arrangement for enclosures containing an interior space in which a protected item is positioned having a magnetoresistive sensing memory storage cell positioned in or near the protected item in the enclosure having a two state offset magnetoresistance versus externally applied magnetic field. A magnet is positioned at a selected separation distance from the magnetoresistive sensing memory storage cell to thereby provide a magnetic field about the magnetoresistive sensing memory storage cell if said enclosure has not been opened in such a manner as to result in substantially increasing said separation distance.

Enclosure tamper detection and protection

A ferromagnetic thin-film based magnetic device with internal film coupling compensation including a nonmagnetic material intermediate layer with an initial thin-film of an anisotropic ferromagnetic material on one side. A compensation thin-film of an anisotropic ferromagnetic material is provided on the opposite side with an antiparallel coupling layer thereon and a subsequent thin-film of an anisotropic ferromagnetic material on the antiparallel coupling layer with the compensation thin-film being less thick than the subsequent thin-film. A antiferromagnetic layer can be supported by the layers on either side of the intermediate layer.

Spin dependent tunneling devices having reduced topological coupling

A ferromagnetic thin-film based magnetic field sensor having an electrically insulative intermediate layer with two major surfaces on opposite sides thereof with an initial film of an anisotropic ferromagnetic material on one of those intermediate layer major surfaces and a superparamagnetic thin-film on the remaining one of said intermediate layer major surfaces.

Superparamagnetic field sensing device

A ferromagnetic thin-film based digital memory having a bit structures therein a magnetic material film in which a magnetic property thereof is maintained below a critical temperature above which such magnetic property is not maintained, and may also have a plurality of word line structures each with heating sections located across from the magnetic material film in a corresponding one of the bit structures. These bit structures are sufficiently thermally isolated to allow selected currents in the adjacent word lines or in the bit structure, or both, to selectively heat the bit structure to approach the critical temperature. Such bit structures may have three magnetic material layers each with its own critical temperature for maintaining versus not maintaining a magnetic property thereof.

magnetic memory layers thermal pulse transitions

A ferromagnetic thin-film based digital memory having a substrate formed of a base supporting an electrically insulating material primary substrate layer in turn supporting a plurality of current control devices each having an interconnection arrangement with each of said plurality of current control devices being separated from one another by spacer material therebetween and being electrically interconnected with information storage and retrieval circuitry. A plurality of bit structures are each supported on and electrically connected to a said interconnection arrangement of a corresponding one of said plurality of current control devices and have magnetic material films in which a characteristic magnetic property is substantially maintained below an associated critical temperature above which such magnetic property is not maintained of which two are separated by at least one intermediate layer of a nonmagnetic material having two major surfaces on opposite sides thereof. A plurality of word line structures located across from a corresponding one of the bit structures on an opposite side of the intermediate layer of a corresponding one of said bit structures from its interconnection arrangement supporting that bit structure. Sufficient electrical current selectively drawn through each of these bit structures as interconnected can cause substantial heating of that bit structure to raise temperatures thereof to have at least one of the magnetic material films therein at least approach its corresponding associated critical temperature while being substantially above temperatures of at least an adjacent said bit structure because of sufficient thermal isolation.

Growing community of inventors

Eden Prairie, MN, United States of America

James M Daughton