Kabushiki Kaisha Toshiba

National Institute of Advanced Industrial Science and Technology

Tohoku University

Japan Science and Technology Agency

Taro Nagahama

Shinji Yuasa

Hiroaki Yoda

Tadashi Kai

Tadaomi Daibou

Koji Ando

Akio Fukushima

Hitoshi Kubota

Kay Yakushiji

Toshihiko Nagase

Eiji Kitagawa

Katsuya Nishiyama

Makoto Nagamine

Minoru Amano

Junichi Ito

Shigemi Mizukami

Terunobu Miyazaki

Takahide Kubota

Masatoshi Yoshikawa

Masahiko Nakayama

Naoharu Shimomura

Koji Ueda

Yoshishige Suzuki

Kei Yakushiji

Yutaka Hashimoto

Masaru Tokou

A magnetoresistive element according to an embodiment includes: a base layer; a first magnetic layer formed on the base layer, and including a first magnetic film having an axis of easy magnetization in a direction perpendicular to a film plane, the first magnetic film including MnGa(45&#x2266;x&#x3c;64 atomic %); a first nonmagnetic layer formed on the first magnetic layer; and a second magnetic layer formed on the first nonmagnetic layer, and including a second magnetic film having an axis of easy magnetization in a direction perpendicular to a film plane, the second magnetic film including MnGa(45&#x2266;y&#x3c;64 atomic %). The first and second magnetic layers include different Mn composition rates from each other, a magnetization direction of the first magnetic layer is changeable by a current flowing between the first magnetic layer and the second magnetic layer via the first nonmagnetic layer.

Magnetoresistive element and magnetic memory

A magnetoresistive element according to an embodiment includes: a first and second magnetic layers having an easy axis of magnetization in a direction perpendicular to a film plane; and a first nonmagnetic layer interposed between the first and second magnetic layers, at least one of the first and second magnetic layers including a structure formed by stacking a first and second magnetic films, the second magnetic film being located closer to the first nonmagnetic layer, the second magnetic film including a structure formed by repeating stacking of a magnetic material layer and a nonmagnetic material layer at least twice, the nonmagnetic material layers of the second magnetic film containing at least one element selected from the group consisting of Ta, W, Hf, Zr, Nb, Mo, Ti, V, and Cr, one of the first and second magnetic layers having a magnetization direction that is changed by applying a current.

According to one embodiment, a magnetoresistive effect element includes a first magnetic layer including perpendicular anisotropy to a film surface and an invariable magnetization direction, the first magnetic layer having a magnetic film including an element selected from a first group including Tb, Gd, and Dy and an element selected from a second group including Co and Fe, a second magnetic layer including perpendicular magnetic anisotropy to the film surface and a variable magnetization direction, and a nonmagnetic layer between the first magnetic layer and the second magnetic layer. The magnetic film includes amorphous phases and crystals whose particle sizes are 0.5 nm or more.

Magnetoresistive effect element, magnetic memory

According to one embodiment, a magnetoresistive element includes a first magnetic layer with a variable magnetization and an easy-axis in a perpendicular direction to a film surface, a second magnetic layer with an invariable magnetization and an easy-axis in the perpendicular direction, and a first nonmagnetic layer between the first and second magnetic layers. The first magnetic layer comprises a ferromagnetic material including an alloy in which Co and Pd, or Co and Pt are alternately laminated on an atomically close-packed plane thereof. The first magnetic layer has C-axis directing the perpendicular direction. And a magnetization direction of the first magnetic layer is changed by a current flowing through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer.

By varying only the thickness of a known material having superior magnetic characteristics to increase spin polarization without changing the chemical composition, a tunnel magnetoresistive element capable of producing a larger magnetoresistive effect is provided. The tunnel magnetoresistive element includes an underlayer (nonmagnetic or antiferromagnetic metal film); an ultrathin ferromagnetic layer disposed on the underlayer; an insulating layer disposed on the ultrathin ferromagnetic layer; and a ferromagnetic electrode disposed on the insulating layer.

Tunnel magnetoresistance element having a double underlayer of amorphous MgO and crystalline MgO(001)

Tunnel magnetoresistance element

Growing community of inventors

Tsukuba, Japan

Taro Nagahama