National Institute for Materials Science

Samsung Electronics Co., Ltd.

Tdk Corporation

Kabushiki Kaisha Toshiba

Hiroaki Sukegawa

Kazuhiro Hono

Seiji Mitani

Tadakatsu Ohkubo

Koichiro Inomata

Jun Liu

Takao Furubayashi

Katsuyuki Nakada

Shinto Ichikawa

Yuya Sakuraba

Shinya Kasai

Thomas Scheike

Hwachol Lee

Wenhong Wang

Jiamin Chen

Jungwoo Koo

Jason Paul Hadorn

Zhenchao Wen

Kouichiro Inomata

Junichi Ito

Tadaomi Daibou

Naoharu Shimomura

Shigeki Takahashi

Yuuzo Kamiguchi

Yushi Kato

Yoshiaki Sonobe

Kwangseok Kim

Masafumi Shirai

Yoshio Miura

Masaya Kodzuka

Ikhtiar

Xiandong Xu

Mohamed Belmoubarik

Po-Han Cheng

Tomohiko Niizeki

Kazutaka Abe

Shingo Muramoto

Rong Shan

A magnetoresistive effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, wherein the non-magnetic layer includes a first layer and a second layer, and wherein a lattice constant &#x3b1; of the first layer and a lattice constant &#x3b2; of the second layer satisfy a relationship of &#x3b2;&#x2212;0.04&#xd7;&#x3b1;&#x2264;2&#xd7;&#x3b1;&#x2264;&#x3b2;+0.04&#xd7;&#x3b1;.

Magnetoresistive effect element containing two non-magnetic layers with different crystal structures

The present invention provides a perpendicularly magnetized film structure exhibiting high interface-induced magnetic anisotropy by utilizing a combination of an alloy comprising Fe as a main component and MgAlOas a basic configuration.

Precursor structure of perpendicularly magnetized film, perpendicularly magnetized film structure and method for manufacturing the same, perpendicular magnetization-type magnetic tunnel junction film in which said structure is used and method for manufacturing the same, and perpendicular magnetization-type magnetic tunnel junction element in which said structure or magnetic tunnel junction film is used

The object of the present invention is to attain an unconventionally high tunnel magnetoresistance (TMR) ratio by using a barrier layer made of an MgAlOtype insulator material with a spinel structure. The problem can be solved by a magnetic tunnel junction in which a barrier layer is made of a cubic nonmagnetic material having a spinel structure, and both of two ferromagnetic layers that are adjacently on and below the barrier layer are made of a CoFeAl Heusler alloy. Preferably, the nonmagnetic material is made of oxide of an MgAl(0&#x3c;x&#x2264;1) alloy, and exhibits tunnel magnetoresistance of 250% or more and 34000% or less at a room temperature.

Magnetic tunnel junction, magnetoresistive element and spintronics device in which said magnetic tunnel junction is used, and method of manufacturing magnetic tunnel junction

According to an embodiment, a magnetic tunnel junction includes a tunnel barrier layer provided between a first magnetic layer and a second magnetic layer. The tunnel barrier layer is a crystal body made of a stacked structure of a first insulating layer and a second insulating layer. The crystal body is oriented. The first insulating layer is made of an oxide of MgX(0&#x2264;x&#x2264;0.15). X includes at least one element selected from the group consisting of Al and Ti. The second insulating layer is made of an oxide of an alloy including at least two elements selected from the group consisting of Mg, Al, Zn, and Li. Both the first magnetic layer and the second magnetic layer are made of an alloy including B and at least one element selected from the group consisting of Co and Fe.

Magnetic tunnel junction, spintronics device using same, and method for manufacturing magnetic tunnel junction

Disclosed is a perpendicularly magnetized film structure using a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow, comprising a substrate of a cubic single crystal substrate having a (001) plane or a substrate having a cubic oriented film that grows to have the (001) plane; an underlayer formed on the substrate from a thin film of a metal having an hcp structure in which the [0001] direction of the thin metal film forms an angle in the range of 42&#xb0; to 54&#xb0; with respect to the &#x3c;001&#x3e; direction or the (001) orientation of the substrate; and a perpendicularly magnetized layer located on the metal underlayer and formed from a cubic material selected from a Co-based Heusler alloy and a cobalt-iron (CoFe) alloy having a bcc structure a constituent material, and grown to have the (001) plane.

Underlayer for perpendicularly magnetized film, perpendicularly magnetized film structure, perpendicular MTJ element, and perpendicular magnetic recording medium using the same

To provide a key monocrystalline magnetoresistance element necessary for accomplishing mass production and cost reduction for applying a monocrystalline giant magnetoresistance element using a Heusler alloy to practical devices. A monocrystalline magnetoresistance element of the present invention includes a silicon substrate, a base layerhaving a B2 structure laminated on the silicon substrate, a first non-magnetic layerlaminated on the base layerhaving a B2 structure, and a giant magnetoresistance effect layerhaving at least one laminate layer including a lower ferromagnetic layer, an upper ferromagnetic layer, and a second non-magnetic layerdisposed between the lower ferromagnetic layerand the upper ferromagnetic layer

Monocrystalline magneto resistance element, method for producing the same and method for using same

Provided is a magnetoresistance effect element in which a tunnel barrier layer stably has a cation disordered spinel structure. This magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. In addition, the tunnel barrier layer is an oxide of MgAl(0&#x2264;x&#x3c;1) and an amount of oxygen in the tunnel barrier layer is lower than an amount of oxygen in a fully oxidized state in which the oxide has an ordered spinel structure.

Magnetoresistance effect element and method for manufacturing the same

Embodiments of the inventive concepts provide a flat perpendicular magnetic layer having a low saturation magnetization and a perpendicular magnetization-type tunnel magnetoresistive element using the same. The perpendicular magnetic layer is a nitrogen-poor (MnGa)Nlayer (0&#x3c;x&#x2264;0.5 and 0&#x3c;y&#x3c;0.1) formed by providing nitrogen (N) into a MnGa alloy while adjusting a nitrogen amount. The perpendicular magnetic layer can be formed flat.

Perpendicular magnetic layer and magnetic device including the same

According to one embodiment, a magnetoresistive element includes a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer. The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The first nonmagnetic layer includes an oxide including an inverse-spinel structure.

Magnetoresistive element and magnetic memory device

Disclosed is a perpendicularly magnetized film structure that uses a highly heat resistant underlayer film on which a cubic or tetragonal perpendicularly magnetized film can grow with high quality, the structure comprising any one substrate () of a cubic single crystal substrate having a (001) plane, or a substrate having a cubic oriented film that grows to have the (001) plane; an underlayer () formed on the substrate () from a thin film of a metal having an hcp structure, such as Ru or Re, in which the [0001] direction of the thin metal film forms an angle in the range of 42&#xb0; to 54&#xb0; with respect to the &#x3c;001&#x3e; direction or the (001) orientation of the substrate (); and a perpendicularly magnetized layer () located on the metal underlayer () and formed from a cubic material selected from the group consisting of a Co-based Heusler alloy, a cobalt-iron (CoFe) alloy having a bcc structure, and the like, as a constituent material, and grown to have the (001) plane.

Provided is a structure having a perpendicular magnetization film which is an (MnGa)N(0&#x3c;x&#x2266;0.5, 0&#x3c;y&#x3c;1) thin film having a nitrogen-deficient composition which is formed by controlling and introducing nitrogen N into an MnGa alloy or a thin film containing at least one of Ge, Zn, Sb, Ni, Ag, Sn, Pt, and Rh, instead of Ga. The perpendicular magnetization film exhibits a Curie temperature sufficiently higher than room temperature, has saturation magnetization smaller than that of existing materials, and is capable of being fabricated as a very flat film.

Perpendicular magnetization film, perpendicular magnetization film structure, magnetoresistance element, and perpendicular magnetic recording medium

A ferromagnetic tunnel junction structure comprising a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer, wherein the tunnel barrier layer includes a crystalline non-magnetic material having constituent elements that are similar to those of an crystalline oxide that has spinel structure as a stable phase structure; the non-magnetic material has a cubic structure having a symmetry of space group Fm-3m or F-43m in which atomic arrangement in the spinel structure is disordered; and an effective lattice constant of the cubic structure is substantially half of the lattice constant of the oxide of the spinel structure.

Ferromagnetic tunnel junction structure and magnetoresistive effect device and spintronics device utilizing same

For the present ferromagnetic tunnel junction structure, employed is a means characterized by using an MgO barrier and using a CoFeAl full-Heusler alloy for any of the ferromagnetic layers therein. The ferromagnetic tunnel junction structure is characterized in that CoFeAl includes especially a B2 structure and one of the ferromagnetic layers is formed on a Cr buffer layer. The magnetoresistive element is characterized in that the ferromagnetic tunnel junction structure therein is any of the above-mentioned ferromagnetic tunnel junction structure. Accordingly, a large TMR, especially a TMR over 100% at room temperature can be attained, using CoFeAl having a smallest &#x3b1; though not a half-metal.

Ferromagnetic tunnel junction structure and magnetoresistive element using the same

Disclosed is a ferromagnetic tunnel junction structure which is characterized by having a tunnel barrier layer that comprises a non-magnetic material having a spinel structure. The ferromagnetic tunnel junction structure is also characterized in that the non-magnetic material is substantially MgAlO. The ferromagnetic tunnel junction is also characterized in that at least one of the ferromagnetic layers comprises a Co-based full Heusler alloy having an L2or B2 structure. The ferromagnetic tunnel junction structure is also characterized in that the Co-based full Heusler alloy comprises a substance represented by the following formula: CoFeAlSi(0&#x2266;x&#x2266;1). Also disclosed are a magnetoresistive element and a spintronics device, each of which utilizes the ferromagnetic tunnel junction structure and can achieve a high TMR value, that cannot be achieved by employing conventional tunnel barrier layers other than a MgO barrier.

Growing community of inventors

Ibaraki, Japan

Hiroaki Sukegawa