Nec Corporation

Matsushita Electric Industrial Co., Ltd.

Tdk Corporation

Nippon Steel Corporation

Ube Industries, Inc.

Tosoh Corporation

Seisan Kaihatsu Kagaku Kenkyusho

Toyo Boseki Kabushiki Kaisha

Japan Energy Corporation

Kanegafuchi Chemical Industry Co., Ltd.

Nippon Mining Co., Ltd.

Hidefumi Yamamoto

Kazuhiko Hayashi

Kunihiko Ishihara

Jun-Ichi Fujikata

Masafumi Nakada

Toshio Takada

Teruya Shinjo

Junichi Fujikata

Toshihiko Anno

In a magnetoresistive element, an underlying metal layer is formed on a substrate, and a magnetoresistive layer is formed on the underlying metal layer. The underlying metal layer has a thickness of about 0.1 to 3.0 nm.

Magnetoresistive effect element having magnetoresistive layer and

The invention provides a magnetoresistance effects film including (a) at least two thin magnetic films deposited on a substrate, (b) at least one thin nonmagnetic film interposed between the thin magnetic films, and (c) a thin antiferromagnetic film disposed adjacent to one of the thin magnetic films between which the thin nonmagnetic film is interposed. A bias magnetic field of one of the thin magnetic films induced by the thin antiferromagnetic film has an intensity Hr greater than a coercivity H.sub.C2 of the other of the thin magnetic films which is remote from the thin antiferromagnetic film (Hr&gt;H.sub.C2). The thin antiferromagnetic film has a superlattice structure composed of at least two of NiO, Ni.sub.x Co.sub.1-x O(x=0.1-0.9) and CoO. A ratio of Ni relative to Co in the number of atoms in the superlattice structure is set equal to or greater than 1.0. The magnetoresistance effects film exhibits large linear change in resistance with the hysteresis being small even when a small external field is applied thereto.

Magnetoresistance effects film

A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc.sub.2 of the other ferromagnetic thin film.

Magnetoresistance effect film and production process thereof

Magnetic thin films 2 and 3 are stacked on a substrate 4 with a nonmagnetic thin film 1 interposed therebetween. An antiferromagnetic thin film 5 is arranged adjacent to one magnetic thin film 3. The inequality Hc.sub.2 &lt;Hr is satisfied between a bias magnetic field Hr of the antiferromagnetic thin film 5 and coercive force Hc.sub.2 of the other magnetic thin film 2. At least a part of the antiferromagnetic thin film 5 comprises NiMn of an fct structure. Alternatively, the antiferromagnetic thin film 5 comprises a two-layer structure composed of a CoO layer deposited on a NiO layer to a thickness between 10 and 40 angstroms.

Magnetoresistance effect film, a method of manufacturing the same, and

A magnetoresistive element includes a first magnetic layer; and laminations of a second magnetic layer, a non-magnetic layer and a third magnetic layer. The laminations are adjacent to the first magnetic layer. The second magnetic layer and the third magnetic layer have different coercive forces, wherein the first magnetic layer is selected from CoCrTa, NdFe, and alloys thereof.

Magnetoresistive element

The invention provides a magnetoresistance effects film including (a) at least two thin magnetic films deposited on a substrate, (b) at least one thin nonmagnetic film interposed between the thin magnetic films, and (c) a thin antiferromagnetic film disposed adjacent to one of the thin magnetic films between which the thin nonmagnetic film is interposed. A bias magnetic field of one of the thin magnetic films induced by the thin antiferromagnetic film has an intensity Hr greater than a coercivity H.sub.C2 of the other of the thin magnetic films which is remote from the thin antiferromagnetic film (Hr&gt;H.sub.C2). The thin antiferromagnetic film has a superlattice structure composed of at least two of NiO, Ni.sub.x Co.sub.1-x O (x=0.1-0.9) and CoO. A ratio of Ni relative to Co in the number of atoms in the superlattice structure is set equal to or greater than 1.0. The magnetoresistance effects film exhibits large linear change in resistance with the hysteresis being small even when a small external field is applied thereto.

A magnetoresistive element generally includes consecutively an antiferromagnetic layer, a first ferromagnetic layer, a non-mangetic layer, and a second ferromagnetic layer. Instead of the non-magnetic layer, the magnetoresistive element may include a combination of a Co layer, a non-magnetic layer, and a Co layer. The antiferromagnetic layer is made of nickel oxide, a mixture of nickel oxide and cobalt oxide, or a laminate of nickel oxide and cobalt oxide. The ferromagnetic layer has a thickness of 1 to 10 nm, and the element has a height of 0.1 to 1 um. The non-magnetic layer has a thickness of 2 to 3 nm, and the antiferromagnetic layer has a thickness of 5 to 30 nm. The magnetoresistive element has an appropriate cross point, outputs an excellent reproduced signal, and has a desirable half-width with respect to the output signal.

Magnetoresistive element and sensor having optimal cross point

The magnetoresistive effect element in accordance with the invention has several aspects. For instance, the magnetoresistive effect element includes an artificial lattice multilayered structure composed of a thin magnetic layer and a non-magnetic layer at least once successively deposited, and a bias field applying device for applying a bias magnetic field to the artificial lattice multilayered structure so that an orientation of residual magnetization of one of the thin magnetic layers having a greater coercive force than that of an adjacent thin magnetic layer, is the same as an orientation of a bias magnetic field to be applied to the artificial lattice multilayered structure. The magnetoresistive effect element provides enhanced regenerated outputs and also improves the symmetry of regenerated waveforms.

Magnetoresistive effect element

A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc2 of the other ferromagnetic thin film.

In an artificial superlattice magnetoresistance effect element in which two or more of magnetic thin film layers having different coercive forces are stacked with intervening of a non-magnetic film layer and resistance changes depending on directions of magnetization in adjacent magnetic thin film layers by utilizing differences in the coercive forces, an anisotropy magnetic field Hk is increased by reducing a thickness of a soft magnetic layer, anisotropy in the magnetic thin film layer is obtained by forming the magnetic thin film layer in a magnetic field to thus increase the Hk, a material having large Hk is used as a soft magnetic material for the soft magnetic layer, and further the anisotropy is obtained by reducing a pattern width into 1-30 .mu.m to thus increase the Hk, whereby the resistance change is achieved in the neighborhood of a zero magnetic field and thus no bias mechanism is required.

Magnetoresistance effect elements and method of fabricating the same

The invention relates to a magnetoresistance material, i.e. a conductive material that exhibits magnetoresistance, which is an inhomogeneous system consisting of a nonmagnetic matrix and ultrafine particles of a ferromagnetic material such as Co or Ni--Fe--Co dispersed in the nonmagnetic matrix. With the aim of reducing deterioration of the magnetoresistance effect, an alloy or mixture of at least two metal elements selected from Cu, Ag, Au and Pt is used as the material of the nonmagnetic matrix. Optionally, the nonmagnetic matrix may contain a limited quantity of a supplementary element selected from Al, Cr, In, Mn, Mo, Nb, Pd, Ta, Ti, W, V, Zr and Ir. A film of the magnetoresistance material can be formed on a substrate, and it is optional to interpose a buffer layer between the film and the substrate and/or cover the film with a protective layer.

Magnetoresistance film which is a matrix of at least two specified

A magnetoresistance effect element having a substrate, a buffer layer of a metal selected from the group consisting of chromium, tungsten, titanium, vanadium, manganese and their alloys which is formed on the substrate, and at least two magnetic thin layers which are laminated with interposing a non-magnetic thin layer therebetween on the metal thin layer, wherein adjacent magnetic thin layers through the non-magnetic thin layer have different coercive forces. This magnetoresistance effect element has an increased magnetoresistance ratio.

Magnetoresistance effect element

There is provided a magnetoresistance effect element comprising a substrate and at least two magnetic thin layers which are laminated with interposing a non-magnetic thin layer therebetween on said substrate, wherein adjacent magnetic thin layers through the non-magnetic thin layer have different coercive forces, characterized in that a metal thin film is provided in an interface between at least one of the magnetic layers and the non-magnetic layer which is adjacent thereto, and the metal thin film is made of a substance which is different from that of the adjacent non-magnetic layer.

Growing community of inventors

Tokyo, Japan

Hidefumi Yamamoto