Centre National De La Recherche Scientifique

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Commissariat a L'energie Atomique

Institut Polytechnique De Grenoble

Université Grenoble Alpes

Crocus-technology Sa

Université Paris—sud

Centre National De La Recherche Scientifique-cnrs

Institut National Polytechnique De Grenoble

Université Joseph Fourier - Grenoble

Le Commissariat a L'energie Atomique Et Aux Energies Altenatives

Crocus Technology Inc.

Ricardo Sousa

Bernard Dieny

Ioan Lucian Prejbeanu

Lucian Prejbeanu

Olivier Redon

Ioan-Lucian Prejbeanu

Jean-Pierre Nozieres

Nicolas Perrissin-Fabert

Jyotirmoy Chatterjee

Liliana Buda-prejbeanu

Dimitri Houssameddine

Ursula Ebels

Clarisse Ducruet

Thibaut Devolder

Jérôme Moritz

Stéphane Auffret

Jerome Moritz

Paulo Veloso Coelho

Cristian Papusoi

Liliana Buda-Prejbeanu

Cécile Maunoury

Dana Stanescu

Bertrand Lacoste

Pedro Brandao Veiga

Hélène Bea

Cécile Grezes

Jérémy Alvarez-Hérault

Marco Mansueto

Isabelle Joumard

Stéphne Auffret

Alvarez-Hérault Jérémy

Nuno-Filipe Fernandes Caçoilo

Olivier Fruchart

A method for measuring the intensity of an external magnetic field by using a magnetic memory point including a storage layer having a magnetisation switchable between two magnetisation directions substantially perpendicular to the plane of the layer; a reference layer having a fixed magnetisation perpendicular to the plane of the layer; and a tunnel barrier layer separating the storage layer and the reference layer; the method including successively applying a plurality of currents or voltages of different amplitudes to the memory point until switching of the magnetisation direction of the storage layer takes place to determine a minimum switching current value of the magnetisation direction of the storage layer or a minimum switching voltage value of the magnetisation direction of the storage layer, and determining the intensity of the external magnetic field to be measured from the minimum switching current value or the minimum switching voltage value.

Method for measuring an external magnetic field by at least one magnetic memory point

A magnetic tunnel junction includes at least one free layer, at least one reference layer, and at least one tunnel barrier separating the free layer and the reference layer, wherein the free layer is an inhomogeneous granular layer including at least two grains, each grain of the at least two grains being sensibly magnetically decoupled from the other adjacent grains of the at least two grains.

Magnetic tunnel junction comprising an inhomogeneous granular free layer and associated spintronic devices

A cryogenic magnetic device includes a free layer having a free magnetisation and a magnetic anisotropy favouring the orientation of the free magnetisation according to a first orientation or a second orientation, the magnetic anisotropy being defined by an energy barrier separating the first orientation and the second orientation, the amplitude of the energy barrier being less than 6300 k, the free layer having a Gilbert damping factor comprised between 0.02 and 0.4; a tunnel barrier extending in contact with the free layer; and a system configured to apply a voltage pulse through the tunnel barrier so as to reduce the amplitude of the energy barrier and switch the free magnetisation.

Cryogenic magnetic device more particularly for logic component or memory

The invention relates to a directional magnetic field generator with a magnetic circuit comprising: a first vertical-axis pole end () arranged above a horizontal plane; and at least two second pole ends (A toD) symmetrically arranged on said horizontal plane, the generator further comprising coils arranged such that each magnetic circuit portion connecting two pole ends passes inside at least one coil, these coils being suitable for being connected to circuits for circulating currents of adjustable intensity in selected directions therein.

Magnetic field generator

A magnetic stack includes a first element including a ferromagnetic layer; a second element including a metal layer able to confer on the assembly formed by the first and the second elements a magnetic anisotropy perpendicular to the plane of the layers. The first element further includes a refractory metal material, the second element being arranged on the first element.

Magnetic stack, multilayer, tunnel junction, memory point and sensor comprising such a stack

A magnetic tunnel junction with out-of-plane magnetisation includes a storage layer; a reference layer; a tunnel barrier layer, the two magnetisation states of the storage layer being separated by an energy barrier, the magnetic tunnel junction having a thermal stability factor dependent on the energy barrier and on the temperature of use of the magnetic tunnel junction. The storage layer has a thickness comprised between 0.5 times and 8 times a characteristic dimension of a planar section of the tunnel junction; the composition and the thickness of the storage layer are chosen such that the absolute value of the derivative of the thermal stability factor compared to a characteristic dimension of a planar section of the tunnel junction is less than 10 nm.

Magnetic tunnel junction with perpendicular shape anisotropy and minimised variability, memory point and logic element including the magnetic tunnel junction, method for manufacturing the magnetic tunnel junction

A magnetic tunnel junction with out-of-plane magnetisation includes a storage layer; a reference layer; and a tunnel barrier layer. The two magnetisation states of the storage layer are separated by an energy barrier including a contribution due to the shape anisotropy of the storage layer and a contribution of interfacial origin for each interface of the storage layer. The storage layer has a thickness comprised between 0.8 and 8 times a characteristic dimension of a planar section of the tunnel junction. The contribution to the energy barrier due to the shape anisotropy of the storage layer is at least two times greater and preferably at least 4 times greater than the contributions to the energy barrier of interfacial origin.

Magnetic tunnel junction with perpendicular shape anisotropy and minimised variation of temperature memory point and logic element including the magnetic tunnel junction, method of manufacturing the magnetic tunnel junction

A synthetic antiferromagnetic layer includes a first ferromagnetic layer containing an amorphizing element, the first ferromagnetic layer having a first structural symmetry; a second ferromagnetic layer having a second structural symmetry; wherein the first and the second ferromagnetic layers are antiferromagnetically coupled by a trifunctional non-magnetic multi-layered structure, the antiferromagnetic coupling being an Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling, the non-magnetic multi-layered structure including at least two non-magnetic layers, the non-magnetic multilayered structure being at least partially nano-crystalline or amorphous in order to ensure a structural transition between the first ferromagnetic layer having the first structural symmetry and the second ferromagnetic layer having the second structural symmetry, the non-magnetic multilayered structure being adapted to absorb at least part of the amorphizing element out of the first ferromagnetic layer in contact with the non-magnetic multi-layered structure.

Synthetic antiferromagnetic layer, magnetic tunnel junction and spintronic device using said synthetic antiferromagnetic layer

A magnetic device includes a first magnetic layer, known as storage layer, having a uniaxial anisotropy with an easy magnetization axis in the plane of the storage layer and having a magnetization of variable direction having two positions of equilibrium along the easy magnetization axis, a second magnetic layer, known as electron spin polarization layer, having a magnetization perpendicular to that of the storage layer and situated out of plane of the electron spin polarization layer, a device configured to make circulate in the layers, and perpendicularly thereto, a current to switch from one position of equilibrium of the direction of magnetization of the storage layer to the other. The device further includes a device to apply a magnetic field, known as transverse field, the direction of which is substantially parallel to the plane of the storage layer and substantially perpendicular to the easy magnetization axis of the storage layer.

Magnetic device with spin polarisation

Method for writing to a MRAM cell including a magnetic tunnel junction including a first and second ferromagnetic layer, and a tunnel barrier layer; and a bipolar transistor in electrical connection with one end of the magnetic tunnel junction, the bipolar transistor being arranged for controlling the passing and polarity of a heating current in the magnetic tunnel junction. The method includes a sequence of writing steps, each writing step including passing the heating current in the magnetic tunnel junction such as to heat it to a high temperature threshold; and once the magnetic tunnel junction has reached the high temperature threshold, adjusting a second magnetization of the second ferromagnetic layer for writing a write data; wherein during one of the writing steps, the polarity of the heating current is reversed from one during the subsequent writing step. The method allows for an increased lifespan of the MRAM cell.

Method for writing to a random access memory (MRAM) cell with improved MRAM cell lifespan

The present disclosure concerns a method for writing to a MRAM cell comprising a magnetic tunnel junction formed from a storage layer having a storage magnetization; a reference layer having a reference magnetization; and a tunnel barrier layer included between the sense and storage layers; and a current line electrically connected to said magnetic tunnel junction; the method comprising: passing a heating current in the magnetic tunnel junction for heating the magnetic tunnel junction; passing a field current for switching the storage magnetization in a written direction in accordance with the polarity of the field current. The magnitude of the heating current is such that it acts as a spin polarized current and can adjust the storage magnetization; and the polarity of the heating current is such as to adjust the storage magnetization substantially towards said written direction.

MRAM cell and method for writing to the MRAM cell using a thermally assisted write operation with a reduced field current

A magnetic thermally-assisted switching device includes a reference layer, a storage layer magnetised along a variable direction, a spacer that separates the reference layer and the storage layer, and magnetically decouples them, a device for heating the pinning layer so that, during heating, the temperature of the pinning layer exceeds its blocking temperature such that the direction of magnetisation of the storage layer is no longer pinned, a device for applying a writing magnetic torque tending to align the magnetisation of the storage layer along one of two stable magnetisation directions once the blocking temperature is reached. The device also includes a device for applying a magnetic polarisation field at least during the heating phase before the blocking temperature is reached such that the direction of magnetisation of the storage layer is always along the direction of the magnetic polarisation field at the moment that the blocking temperature is reached.

Magnetic device with thermally-assisted switching

A thermally assisted magnetic writing device including a first magnetic layer known as the 'reference layer,' a second magnetic layer known as the 'storage layer' that presents a variable magnetization direction, a spacer situated between the reference layer and the storage layer and a first antiferromagnetic layer in contact with the storage layer, the first antiferromagnetic layer being able to trap the magnetization direction of the storage layer. The magnetic device also includes a stabilization layer made of a ferromagnetic material, the stabilization layer being in contact with the first antiferromagnetic layer.

Thermally assisted magnetic writing device

The present disclosure concerns memory device comprising magnetic tunnel junction comprising a tunnel barrier layer between a first ferromagnetic layer having a first magnetization with a fixed orientation and a second ferromagnetic layer having a second magnetization being freely orientable, and a polarizing layer having a polarizing magnetization substantially perpendicular to the first and second magnetization; the first and second ferromagnetic layers being annealed such that a tunnel magnetoresistance of the magnetic tunnel junction is equal or greater than about 150%. Also disclosed is a method of forming the MRAM cell.

Magnetic tunnel junction comprising a polarizing layer

A magnetic device includes a magnetic reference layer with a fixed magnetization direction located either in the plane of the layer or perpendicular to the plane of the layer, a magnetic storage layer with a variable magnetization direction, a non-magnetic spacer separating the reference layer and the storage layer and a magnetic spin polarizing layer with a magnetization perpendicular to that of the reference layer, and located out of the plane of the spin polarizing layer if the magnetization of the reference layer is directed in the plane of the reference layer or in the plane of the spin polarizing layer if the magnetization of the reference layer is directed perpendicular to the plane of the reference layer. The spin transfer coefficient between the reference layer and the storage layer is higher than the spin transfer coefficient between the spin polarizing layer and the storage layer.

Spin polarised magnetic device

Growing community of inventors

Grenoble, France

Ricardo Sousa