Thomson-csf

Alain Schuhl

Stephane Tyc

Fr&eacute;d&eacute;ric Nguyen Van Dau

Alain Friederich

Albert Fert

Guy Garry

Patrick Etienne

Armando Encinas

Regis Cabanel

Luiz Fernando Schelp

Bruno Ghyselen

Jeffrey Childress

Fr&eacute;d&eacute;ric Petroff

Frederic Nguyen Van Dau

Fran&ccedil;ois Montaigne

A magnetic detector which includes a first thin-layer element and a second thin-layer element made of magnetic material with magnetic anisotropy in the plane possessing, in this plane, two easy axes of magnetization. A coercive field of one of the first and second thin-layer elements has a value different from that of the other thin-layer element. The two thin-layer elements have elongated and mutually parallel shapes perpendicular to their direction of easy magnetization in the absence of a magnetic field. The width of these thin-layer elements is such that it obliges at least one of the thin-layer elements to have its magnetization oriented along the length of the thin-layer element when there is no external magnetic field. Such a magnetic field sensor may find particular application to the measurement of magnetic fields.

Magnetic field sensor using magneto-resistance of ferromagnetic layers with parallel magnetic axes

A magnetic sensor having a layer of nonmagnetic insulator including at least one layer of ferromagnetic particles. This combination of layers is sandwiched between two ferromagnetic electrodes. Electrons are transported by the tunneling effect between each electrode and the ferromagnetic particles. The tunneling resistance depends on the orientation of the magnetization of the electrodes and therefore varies in the presence of the magnetic field. The multichannel and multistage nature of the tunneling conduction eliminates the problems of short-circuiting by porosity, thus leading to less difficult fabrication and improved robustness in terms of breakdown. The possible thermal fluctuations of the magnetic moments of the aggregates can be suppressed by the choice of a magnetic material for the part of the insulating layer which contains the aggregates.

Magnetic field sensor and method for making same

A magnetic field sensor which includes a planar thin-film element made of a crystalline magnetoresistive material exhibiting resistivity anisotropy in a plane, having a first and a second easy axis of magnetization. The planar thin-film element has electrical connections allowing a first electrical measurement current to flow through the planar thin-film element in a first direction, as well as two other electrical connections allowing a voltage to be measured in a second direction transverse to the first direction. The two easy axes of magnetization have comparable magnetization values. The sensor includes an electrical conductor placed parallel to the first easy axis of magnetization, insulated from the magnetoresistive material, and allowing an electrical control current to flow, in which the control current induces, in the planar thin-film element, a magnetic field which imposes, when the sensor is not in use, an orientation of the direction of magnetization of the element parallel to the second easy axis of magnetization.

Planar thin-film magnetic field sensor for determining directional magnetic fields

This ammeter comprises an element made of magnetoresistive material in a thin layer located on a first face of a substrate; first connection means connected to the magnetoresistive element in two zones along a first direction (XX') and enabling the element to be supplied with current; second connection means connected to the magnetoresistive element in two zones located along a second direction (YY') perpendicular to the first direction (XX'). This ammeter enables the measurement of the value of the current flowing in a conductor preferably oriented in a direction (ZZ') parallel to the first direction (XX').

Ammeter

A magnetic field sensor having a planar element made of a material formed by crystalline magnetoresistive thin layers with an anisotropy of resistivity in the planar element also having, in the planar element, two magnetization axes of different values. This sensor also has two electrical connections enabling, in the presence of an external magnetic field, the flow of a current in the element in a first direction that is not collinear with each of the axes of magnetization and two electrical connections enabling a measurement of voltage in a second direction transversal to the first direction. This sensor thus works by planar Hall effect.

Thin-film magnetic field detector having transverse current and voltage

A magnetoresistive detector comprising a stack of layers having different magnetic characteristics (magnetic metal multilayers) wherein there is provision, under the effect of an electrical field, for a transfer of electrons perpendicularly to the layers. To ensure several perpendicular transfers through the same stack of layers, this stack is enclosed between two electrodes, and the electrical conduction of the entire piece is interrupted by a cutting out of the structure in the form of teeth in a Greek key pattern.

Magnetoresistive transducer and method of manufacture

The disclosure relates to a Josephson junction formed by a non-superconducting barrier between two superconducting films of the (R) BaCuO (R=rare earth) group. In order to take advantage of the greater coherence length of superconductors along the CuO planes, i.e. perpendicularly to the long axis 'c' of the crystal unit cell, the superconducting film is oriented so that the axis 'c' is parallel to the plane of the junction. The device can be applied to Josephson junctions and to SQUIDs.

Josephson junction structure

A sensor of weak magnetic fields with magnetoresistive effect features a metallic multilayer formed by alternating magnetic and non-magnetic metals. In order to detect weak fields, a sensor is described wherein a magnetic field is coupled by an anti-ferromagnetic type coupling with a first neighboring magnetic layer and by a ferromagnetic type coupling with a third neighboring magnetic layer, so that there is frustration of coupling. The first and third magnetic layers are blocked by their strong coercive field. The sensor finds particular application to detection on magnetic media.

Sensor of weak magnetic fields, with magnetoresistive effect

Disclosed is a transistor or diode type Josephson effect device, at least two electrodes of which are made of superconductive material. If the Josephson effect is to be exerted in a semiconductor layer between the access electrodes, the distance between them should be smaller than the length of coherence, namely 10 to 1000 angstroms. According to the disclosure, the control channel between access electrodes is replaced by two channels perpendicular to the semiconductor layer, located between the two access electrodes and a layer of superconductive material placed between the substrate and the semiconductor layer. The disclosure can be applied to transistors, phototransistors and diodes with high switching speed.

Josephson effect semiconductor device with channel layers of

A field-effect transistor comprises, on a substrate, a layer of semiconductor material incorporating natural or artificial inclusions of superconducting material. The source, drain and gate electrodes are made on this layer. Applications: field-effect transistors with low gate control voltage. FIG. 3.

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Clamart, France

Alain Schuhl