Commissariat a L'energie Atomique

Agence Nationale De Valorisation De La Recherche (anvar)

Hubert Jouve

Jean-Marc Fedeli

Joel Magnin

Serge Valette

Stephane Renard

Daniel Mauduit

Mokhtar Boshra-Riad

Robert Meyer

Christian Pisella

Philippe Gerard

Jacques Sztern

Gabor Suran

Michel Tessier

Ramanathan Krishnan

Michel Madore

Jean M Fedeli

An integrated magneto-optical read and write head having a magnetic head set back from an optical head. The integrated magneto-optical head includes an optical subassembly having optical input for receiving optical radiation and an optical output positioned in an output plane. A magnetic subassembly includes a magnetic circuit having at least one polar part PPI placed in a plane perpendicular to the output plane, the polar part PPI exhibition a magnetic pole toward a recording medium. The magnetic pole is set back relative to the output plane of the optical output to reduce the difference between the magnetic coercive field below the optical output and the magnetic pole such that a larger range of magneto-optical materials may be employed in magneto-optical heads.

Integrated magneto-optical having a magnetic head set back from an

Pole (P) is offset crosswise (Dt) relative to optical output plane (36) . Magnetic field (H) is increased in a relative way opposite optical output (SO) and the ratio of the fields opposite pole (P) and opposite optical output (SO) is decreased.

Method of making an integrated magnetooptical read and write head

The invention relates to a magnetic bubble store. This store comprises a magnetic garnet layer (1), in which can be formed magnetic bubbles, which are respectively localized by cells. Each cell comprises a pair of localization windows (2, 3), respectively cut from conductive strips (4, 5) of a pair of conductive strips. These strips are insulated from one another and from the garnet and can be respectively traversed by currents (I.sub.1, I.sub.2) for displacing the bubble optionally located in the cell and means (21) for detecting each bubble. The memory is characterized in that the strips of each pair of strips have directions (X, Y) perpendicular to one another, the currents (I.sub.1 I.sub.2) in said strips being respectively parallel to said directions (X, Y).

Magnetic bubble store

A magnetic bubble memory is formed of a series of longitudinally oriented minor registers and at least one transversely oriented major access register, all of these registers having patterns with boundaries defined by ionically implanted zones of a magnetic garnet layer. The memory is formed also with a structure for transferring bubbles from one end of the minor register to the major register, and is further configured with layered material having a predetermined format for displacing the bubbles in each minor register upon application of a rotating magnetic field. The physical structure of the memory also permits a displacement of the bubbles of the major register by the circulation of currents in two electrically conductive sheets which are superimposed on the magnetic garnet layer. The sheets have windows facing the patterns of the register, with the windows being arranged with end portions thereof in registration with the pattern boundaries to enable the bubbles to circulate while remaining in contact with the boundaries of the major register pattern in implanted zones of the garnet.

Magnetic bubble memory

The invention relates to a magnetic bubble memory having a first layer of monocrystalline magnetic material with at least one crystallographic axis having the property of being aplanar easy magnetization axis, whereby the first layer has groups of unimplanted, contiguous and aligned motifs, called first motifs, permitting the propagation of the bubbles into a second magnetic layer, positioned below the first magnetic layer, the first motifs being shaped in such a way that two cavities are defined between two first adjacent motifs, wherein each group of first motifs has an axis such that the first motifs of the group are arranged symmetrically with respect to the axis, the groups being arranged parallel to the crystallographic axis of the first layer of material, and wherein it comprises, associated with each group, an electrical conductor, called the first conductor, permitting the duplication of the bubbles, each conductor being arranged perpendicular to the crystallographic axis of the first layer of material, the corresponding group of first motifs being traversed by the conductor.

Magnetic bubble memory with unimplanted motifs

A magnetic bubble store, using adjoining non-implanted motifs as bubble-propagating motifs, the store comprising 3n identical, electrically interconnected storage devices, n being a positive integer, which are produced on an identical circuit chip and each comprise minor loops for storing the bubbles, at least one major loop acting as an access loop for the minor loops, first electrical component enabling bubbles to be transferred from the minor loops to the major loop and vice versa, a second electrical component enabling bubbles to be produced on the major loop, and a third electrical component enabling the bubbles on the major loop to be detected, the third, identical component, each formed by an electric conductor for bubble extension and contraction and a magneto-resistive element, being disposed in directions making an angle of 120.degree. with one another.

Magnetic bubble store with non-implanted motifs and method for

A magnetic bubble store including at least two series of longitudinally oriented major shift registers and a rotating magnetic field for producing a displacement of the bubbles in the minor registers. The series of minor registers are respectively arranged on either side of a transverse boundary. The minor registers of each of the series are constituted by motifs defined by ion implantation in a magnetic garnet layer. On either side of the boundary, these motifs define complementary distributions of implanted areas and non-implanted area.

The invention relates to a process making it possible to obtain at least one homogeneous planar magnetization layer in a material constituted by a ferrimagnetic garnet film epitaxied on an amagnetic substrate. According to this process, at least one implantation of ions, with the exception of ions of gaseous elements and those of metallic elements occurring in the composition of the solvent is performed in the film at a high dose. The film and substrate are annealed in order to recrystallize in monocrystalline form that part of the film made amorphous by implantation. Application to the production of magnetic bubble memories.

Process for obtaining a homogeneous planar magnetization layer in a

A magnetic bubble store formed of a series of longitudinally oriented shift registers and at least one transversely oriented access contour register having a single access point corresponding to each access end of each longitudinally oriented shift register, wherein magnetic bubbles are displaced in the longitudinally oriented shift registers by applying a rotary magnetic field thereto, and wherein magnetic bubbles are displaced in the transversely oriented access contour register by applying an electric current thereto. The longitudinally oriented registers are formed of motifs defined by ion implantation in a magnetic garnet layer. Structure for applying the electrical current to the access contour register includes two conductive sheets superimposed on the magnetic garnet layer in the vicinity of the access ends of the longitudinally oriented registers, wherein the sheets are insulated from one another and from the magetic garnet and include openings arranged in the vicinity of respective access ends of the longitudinally oriented shift registers. Other openings are positioned so as to forward the bubbles which have obtained access to the longitudinally oriented shift registers to an access station or to other longitudinally oriented shift registers.

The easy direction of magnetization of an amorphous magnetic film is brought in the plane of the film by annealing this film in an oxygen-free atmosphere composed of a gas selected from the group comprising argon, neon, krypton and xenon at a temperature below the temperature of crystallization of the alloy which constitutes the film. The depth of penetration of the rare gas into the film is adjusted by modifying the parameters of annealing temperature and time in order to modify the easy direction of magnetization to a greater or lesser depth within the film.

Growing community of inventors

Biviers, France

Hubert Jouve