摘要:
This magnetic multilayer device comprises, on a substrate, an alternating sequence of magnetic metallic layers M and oxide, hydride or nitride layers O. The number of layers M equals at least two. The layers M are continuous. There is interfacial magnetic anisotropy perpendicular to the plane of the layers at the level of the M/O interfaces.
摘要:
A magnetoresistive sensor including: a first pinned-magnetization magnetic layer and a free-magnetization magnetic layer, separated by first separating layer for magnetic uncoupling. The sensor further includes a second pinned-magnetization magnetic layer, separated from the free-magnetization magnetic layer by a second separating layer for magnetic uncoupling, the first and second separating layers being located on either side of the free-magnetization magnetic layer, and the respective magnetizations of the first pinned-magnetization magnetic layer and of the free-magnetization magnetic layer, in the absence of an external field, are substantially orthogonal. The orientation of the magnetization of the second pinned layer is selectable.
摘要:
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), which can include an antiferromagnetic layer adjacent the storage layer. The blocking temperature of the magnetisation magnetization 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 magnetization. A magnetic field (34) or a magnetic torque created by the injection of spin polarized electrons is applied (26) to it orientating its magnetization with respect to that of the reference layer without modifying the orientation of the reference layer.
摘要:
The invention relates to a method of operating a spin-transfer torque structure to generate voltage oscillations, said structure comprising a first layer of magnetic material having a fixed magnetization vector, a spacer of non magnetic material and a second layer of magnetic material having a free magnetization vector. The method includes the application of a current (jop) through said structure and a magnetic field (Hext) in the plane of the second layer. It makes use of a region of bistability and hysteretic behaviour to trigger and stop the voltage oscillations.
摘要:
The present invention relates to a method of fabricating a nanostructure, comprising the following steps: prestructuring a substrate (1) adapted to receive the nanostructure to form a nanorelief (2) on the substrate, the nanorelief having flanks (4) extending from a bottom (1a) of the substrate and a top face (3) extending from said flanks, and then depositing on the substrate pre-structured in this way a single layer or multilayer coating intended to form the nanostructure; and further comprising: adding to the prestructured substrate or to the coating a separation layer adapted to enable separation of the coating and the substrate by external action of mechanical, thermomechanical or vibratory type; and exerting this external action on the substrate and/or the coating to recover selectively a top portion of the coating by separating it from the top face of the nanorelief so that this top portion constitutes some or all of the nanostructure.
摘要:
Magnetoresistive device comprising a spin valve formed from a stack of layers including at least two magnetic layers for which a relative orientation of their magnetisation directions are capable varying under influence of a magnetic field; at least one discontinuous dielectric or semiconducting layer with electrically conducting bridges at least partially passing through a thickness of the dielectric or semiconducting layer, the bridges configured to locally concentrate current that passes transversely through the stack; and means for circulating a current in the spin valve transverse to the plane of the layers, characterised in that the dielectric or semiconducting layer with electrically conducting bridges is arranged inside one of the magnetic layers.
摘要:
The magnetic device comprises a magnetic device comprising a magnetoresistive tunnel junction (100), itself comprising: a reference magnetic layer (120) having magnetization in a direction that is fixed; a storage magnetic layer (110) having magnetization in a direction that is variable; and an intermediate layer (130) acting as a tunnel barrier that is essentially semiconductor or electrically insulating and that separates the reference magnetic layer (120) from the storage magnetic layer (110). The potential profile of the intermediate layer (130) is asymmetrical across the thickness of said layer (130) so as to produce a current response that is asymmetrical as a function of the applied voltage. The device is applicable to magnetic random access memories.
摘要:
This magnetic element with thermally-assisted writing using a field or spin transfer comprises a magnetic reference layer referred to as the “trapped layer”, the magnetisation of which is in a fixed direction; a magnetic storage layer called the “free layer” having a variable magnetisation direction and consisting of a layer made of a ferromagnetic material with magnetisation in the plane of the layer and magnetically coupled to a magnetisation-trapping layer made of an antiferromagnetic material; a semiconductor or an insulating layer with confined-current-paths sandwiched between the reference layer and the storage layer. At least one bilayer consisting respectively of an amorphous or quasi-amorphous material and a material having the same structure or the same crystal lattice as the antiferromagnetic layer is placed in the storage layer between ferromagnetic layer which is in contact with the semiconductor or insulating layer with confined-current-paths and antiferromagnetic layer.
摘要:
This radio-frequency oscillator includes a magnetoresistive device in which a spin-polarised electric current flows. This device comprises a stack of at least a first so-called “anchored” magnetic layer having a fixed magnetisation direction, a second magnetic layer, an amagnetic layer inserted between the above-mentioned two layers, intended to ensure magnetic decoupling of said layers. The oscillator also comprises means of causing a flow of electrons in said layers perpendicular to these layers and, if applicable, of applying an external magnetic field to the structure. The second magnetic layer has an excitation damping factor at least 10% greater than the damping measured in a simple layer of the same material having the same geometry for magnetic excitation having wavelengths equal to or less than the extent of the cone or cylinder of current that flows through the stack that constitutes the magnetoresistive device.
摘要:
A system and method for writing to a magnetic memory written in a thermally assisted manner, each memory point formed by a magnetic tunnel junction, and having a substantially circular cross-section of the memory which is parallel to the plane of the layers forming the tunnel junction. The tunnel junction includes at least a trapped layer with a fixed magnetisation direction, a free layer with a variable magnetisation direction with an insulating layer arranged there between. The free layer is formed from at least one soft magnetic layer and a trapped layer, with the two layers being magnetically coupled by contact. During read operations and at rest, the operating temperature of the memory is lower than the blocking temperature of the free and trapped layers, respectively.