International Business Machines Corporation

Thomas S Plaskett

Thomas R McGuire

Richard Joseph Gambino

James M Harper

James M Brownlow

Erik Klokholm

Michael W McElfresh

A method for forming a giant magnetoresistance sensor and method for making is described incorporating an oriented granular layer wherein the layer has a copper matrix with magnetic particles of a nickel cobalt alloy wherein the magnetic particles have a magnetocrystalline anisotropy constant K.sub.1 in the range from 0 to 3.times.10.sup.4 ergs/cm.sup.3. Alternatively, a silver or gold matrix may be used with magnetic particles of a nickel-iron alloy. The granular layer preferably has a (100) texture to provide the magnetic particles with their easy axes in the plane of the layer. The magnetic particles have their largest dimension in the range from 40 to 400 angstroms. The invention overcomes the problem of requiring a large magnetic field to obtain the saturation .DELTA.R/R. By providing a granular film with magnetic particles of low anisotropy, the saturation field to obtain .DELTA.R/R may be as low as 10 to 20 Oe.

Method of forming a giant magnetoresistance sensor

An amorphous alloy containing uranium and a member selected from the group of N, P, As, Sb, Bi, S, Se, Te, Po and mixtures thereof; and use thereof for storage medium, light modulator or optical isolator.

Amorphous uranium alloy and use thereof

A giant magnetoresistance sensor incorporating an orientated granular layer wherein the layer has a copper matrix with magnetic particles of a nickel cobalt alloy wherein the magnetic particles have a magnetocrystalline anisotropy constant K.sub.1 in the range from 0 to 3.times.10.sup.4 ergs/cm.sup.3. Alternatively, a silver or gold matrix may be used with magnetic particles of a nickel-ion alloy. The granular layer preferably has a (100) texture to provide the magnetic particles with their easy axes in the plane of the layer. The magnetic particles have their largest dimension in the range from 40 to 400 angstroms. The invention overcomes the problem of requiring a large magnetic field to obtain the saturation .DELTA.R/R. By providing a granular film with magnetic particles of low anisotropy, the saturation field to obtain .DELTA.R/R may be as low as 10 to 20 Oe.

Oriented granular giant magnetoresistance sensor

A magnetoresistive device is described for detecting magnetic fields incorporating a sandwich structure of four layers, two of which are ferromagnetic and which are separated by a non-ferromagnetic metallic layer and where one ferromagnetic layer is adjacent a fourth antiferromagnetic layer and exhibiting exchange anisotropy with the adjacent ferromagnetic layer. The invention overcomes the problem of small changes in magnetoresistance and in controlling the magnetization response of the magnetoresistive device.

Four layer magnetoresistance device and method for making a four layer

The bonding of an external metal taken from the group of Cu, Ni, Fe, Ti, Mo and alloys thereof to an oxide ceramic substrate is accomplished through the use of an ionic diffusion accommodating metal oxide where the ionic diffusion oxide metal is taken from the group of Fe, Mn, Ti and the combination 33 Ni 67 V. The bond adhesion and processing parameters can be enhanced by addition of Li, Ni, Cu, Co and Mo and the ceramic can be at least one member of the group of glass, pyrex, Al.sub.2 O.sub.3 and SiO.sub.2 glass.

Bonding metal to ceramic like materials

A process is described for the sintering and densification of ceramic materials containing hydrocarbon materials to produce ceramic bodies substantially free from carbonaceous residues of such hydrocarbon materials by compacting ceramic particles and a binder containing a pyrolysis catalyst selected from the group consisting of nickel and palladium ions, heating in a low oxygen atmosphere to a temperature in the range of 350.degree. to 780.degree. C. to remove the carbonaceous residue and further heating the material to produce a sintered, dense ceramic body.

Process for the removal of carbon residues during sintering of ceramics

Bubble domain devices using conventionally known elements for providing a plurality of bubble domain functions, including writing, storage and reading, are provided using a magnetic medium of garnet structure characterized by the presence of a single rare earth ion present in all available dodecahedral lattice sites. These devices operate well over room temperature ranges. This material has sufficiently high anisotropy (of the order 10.sup.5 ergs/cm.sup.3) to support stable magnetic bubble domains in the material. The anisotropy is growth induced and cannot be explained by conventionally accepted theories of anisotropy in garnet bubble domain materials. In preferred embodiments, these rare earth iron garnet films are deposited on suitable substances, which can be any non-magnetic materials having suitable lattice constants to provide substantial lattice match with the magnetic garnet films. Examples are Eu.sub.3 Fe.sub.5 O.sub.12 on Nd.sub.3 Ga.sub.5 O.sub.12 or (Pr,Sm).sub.3 Ga.sub.5 O.sub.12 substrates; and Sm.sub.3 Fe.sub.5 O.sub.12 on (Pr,Nd).sub.3 Ga.sub.5 O.sub.12 substrates.

Growing community of inventors

Katonah, NY, United States of America

Thomas S Plaskett