Kabushiki Kaisha Toshiba

Satoshi Yanagi

Shiho Nakamura

Hirofumi Morise

Daisuke Saida

Yuichi Ohsawa

Akira Kikitsu

Hiroaki Yoda

Masahiko Nakayama

Minoru Amano

Eiji Kitagawa

Naoharu Shimomura

Hisanori Aikawa

Jyunichi Ozeki

Tatsuya Kishi

Masatoshi Yoshikawa

Tadashi Kai

Junichi Ito

Toshiro Hiraoka

Shigeki Takahashi

Sumio Ikegawa

Yoshinari Kurosaki

Saori Kashiwada

Tomotaka Ariga

An example magnetic recording device includes a magnetic recording section and a magnetization oscillator and a first nonmagnetic layer disposed between the magnetic recording section and the magnetization oscillator. The magnetic recording section includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; and a second nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization oscillator includes a third ferromagnetic layer with a variable magnetization direction; a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction; and a third nonmagnetic layer disposed between the third ferromagnetic layer and the fourth ferromagnetic layer.

Magnetic recording device and magnetic recording apparatus

An example magnetic recording device includes a laminated body. The laminated body includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer with a variable magnetization direction; and a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction, wherein at least one of the first and second direction is generally perpendicular to the film plane. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by passing the current in a direction generally perpendicular to the film plane of the layers of the laminated body and the magnetization of the third ferromagnetic layer is able to undergo precession by passing the current.

According to one embodiment, a magnetic memory includes at least one memory cell including a magnetoresistive element, and first and second electrodes. The element includes a first magnetic layer, a tunnel barrier layer, a second magnetic layer, and a third magnetic layer provided on the second magnetic layer and having a magnetization antiparallel to the magnetization direction of the second magnetic layer. A diameter of an upper surface of the first magnetic layer is smaller than that of a lower surface of the tunnel barrier layer. A diameter of a lower surface of the second magnetic layer is not more than that of an upper surface of the tunnel barrier layer.

Magnetic memory

A magnetic memory includes a magnetoresistive element. The magnetoresistive element includes a reference layer having an invariable magnetization direction, a storage layer having a variable magnetization direction, and a spacer layer provided between the reference layer and the storage layer. The storage layer has a multilayered structure including first and second magnetic layers, the second magnetic layer is provided between the first magnetic layer and the spacer layer and has a magnetic anisotropy energy lower than that of the first magnetic layer, and an exchange coupling constant Jex between the first magnetic layer and the second magnetic layer is not more than 5 erg/cm.

Magnetic memory including a magnetoresistive element

A method of forming a concave-convex pattern according to an embodiment includes: forming a guide pattern on a base material, the guide pattern having a convex portion; forming a formative layer on the guide pattern, the formative layer including a stacked structure formed by stacking a first layer and a second layer, the first layer including at least one element selected from a first metal element and a metalloid element, the second layer including a second metal element different from the first metal element; selectively leaving the formative layer only at side faces of the convex portions by performing etching on the formative layer; removing the guide pattern; and forming the concave-convex pattern in the base material by performing etching on the base material, with the remaining formative layer being used as a mask.

Concave-convex pattern forming method and magnetic tunnel junction element forming method

A magnetic recording device includes: a laminated body including: a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; a first nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer; and a third ferromagnetic layer with a variable magnetization direction. The magnetization direction of the second ferromagnetic layer is determinable in response to the orientation of a current, by allowing electrons spin-polarized by passing a current in a direction generally perpendicular to the film plane of the layers of the laminated body to act on the second ferromagnetic layer, and by allowing a magnetic field generated by precession of the magnetization of the third ferromagnetic layer to act on the second ferromagnetic layer.

A magnetic memory is provided with a memory cell. The memory cell includes a magnetic recording element, an interconnection to generate a radio-frequency current-induced magnetic field and a ground line. The magnetic recording element is provided with a first magnetic layer whose magnetization direction is substantially fixed, a magnetic recording layer whose magnetization direction is substantially reversed by spin-polarized electrons passing through the magnetic recording layer and a first nonmagnetic layer provided between the first magnetic layer and the magnetic recording layer. The interconnection is provided above the magnetic recording element to generate a radio-frequency current-induced magnetic field acting in a direction substantially perpendicular to a magnetization easy axis of the magnetic recording layer. The ground line is provided on a side opposite to the magnetic recording element with respect to the interconnection.

A magnetic recording element includes a multilayer having a surface and a pair of electrodes. The multilayer has a first magnetic fixed layer whose magnetization is substantially fixed in a first direction substantially perpendicular to the surface. The multilayer also has a second magnetic fixed layer whose magnetization is substantially fixed in a second direction opposite to the first direction substantially perpendicular to the surface. A third magnetic layer is provided between the first and second magnetic layers. The direction of magnetization of the third ferromagnetic layer is variable. A first intermediate layer is provided between the first and the third magnetic layers. A second intermediate layer is provided between the second and the third magnetic layers. The pair of electrodes is capable of supplying an electric current flowing in a direction substantially perpendicular to the surface to the multilayer. The sectional area taken parallel to the surface at a thickness midpoint of the first magnetic layer is larger than that of the second magnetic layer.

Magnetic recording element

A magnetic memory element is provided with first and second ferromagnetic fixed layers, a ferromagnetic memory layer, nonmagnetic first and second intermediate layers. The memory layer is disposed between the first and second fixed layers, and has a variable magnetization direction. In order to cancel asymmetry of a write-in current of the element, the element is provided so that the memory layer receives a larger perpendicular stray field from the first fixed layer than from the second fixed layer, and then a magnetization direction of a portion of the memory layer being nearest to the first intermediate layer and the magnetization direction of the first fixed layer are antiparallel to each other whenever a magnetization direction of a portion of the memory layer being nearest to the second intermediate layer and the magnetization direction of the second fixed layer are parallel to each other, and vice versa.

Magnetic memory element and magnetic memory apparatus

A magnetic memory element includes a laminated construction of an electrode, a first pinned layer, a first intermediate layer, a first memory layer, a second intermediate layer, a second memory layer, a third intermediate layer, a second pinned layer and electrode. The magnetization direction of the first memory layer takes a first and a second directions and that of the second memory layer takes a third and a fourth directions corresponding to a value and polarity of a current between the electrodes. In response to the current, the second intermediate layer has an electric resistance higher than the first intermediate layer and than the third intermediate layer.

Growing community of inventors

Kanagawa-ken, Japan

Satoshi Yanagi