Tohoku University

Fuji Electric Co., Ltd.

Other

Alps Electric Co., Ltd.

Fuji Electric Device Technology Co., Ltd.

Osamu Kitakami

Yutaka Shimada

Satoshi Okamoto

Takehito Shimatsu

Hajime Aoi

Hiroyuki Uwazumi

Hideo Sato

Tadaaki Oikawa

Hiroyasu Kataoka

Kazuaki Fukamichi

Hiroaki Muraoka

Yoshihisa Nakamura

Naoya Hasegawa

Akihiro Makino

Yoshichika Otani

Hiroko Uyama

Kim Jek Jun

Tomoaki Sakurai

Valentyn Novosad

A perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate (), and at least a nonmagnetic underlayer (), a magnetic recording layer (), and a protective layer () formed in this order on the nonmagnetic substrate (), the magnetic recording layer () comprises a low Kregion () layer having a perpendicular magnetic anisotropy constant (Kvalue) of not more than 1&#xd7;10erg/cm, and a high Kregion () layer having a Kvalue of at least 1&#xd7;10erg/cm. Moreover, the magnetic recording layer () is made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.

Perpendicular magnetic recording medium

There is provided a perpendicular magnetic recording medium according to which both the thermal stability of the magnetization is good and writing with a magnetic head is easy, and moreover the SNR is improved. In the case of a perpendicular magnetic recording medium comprising a nonmagnetic substrate, and at least a nonmagnetic underlayer, a magnetic recording layerand a protective layerformed in this order on the nonmagnetic substrate, the magnetic recording layercomprises a low Kregionlayer having a perpendicular magnetic anisotropy constant (Kvalue) of not more than 1&#xd7;10erg/cm, and a high Kregionlayer having a Kvalue of at least 1&#xd7;10erg/cm. Moreover, the magnetic recording layeris made to have therein nonmagnetic grain boundaries that contain a nonmagnetic oxide and magnetically isolate crystal grains, which are made of a ferromagnetic metal, from one another.

Disclosed are a magnetic thin film capable of providing a high uniaxial magnetic anisotropy, Ku, while suppressing the saturation magnetization Ms thereof, and a method for forming the film; and also disclosed are various devices to which the magnetic thin film is applied. The magnetic thin film comprises a Co-M-Pt alloy having an L11-type ordered structure (wherein M represents one or more metal elements except Co and Pt). For example, the Co-M-Pt alloy is a Co&#x2014;Ni&#x2014;Pt alloy of which the composition comprises from 10 to 35 at. % of Co, from 20 to 55 at. % of Ni and a balance of Pt. The magnetic thin film is applicable to perpendicular magnetic recording media, tunnel magneto-resistance (TMR) devices, magnetoresistive random access memories (MRAM), microelectromechanical system (MEMS) devices, etc.

Magnetic thin film and method for forming the film, and magnetic thin film-applied device

The present invention relates to a magnetic thin film containing a L1type Co&#x2014;Pt&#x2014;C alloy in which atoms are orderly arranged, and can realize an order degree excellent in regard to the L1type Co&#x2014;Pt&#x2014;C alloy to achieve excellent magnetic anisotropy of the magnetic thin film. Therefore, in the various application devices using the magnetic thin film, it is possible to achieve a large capacity process and/or a high density process thereof in a high level.

Magnetic thin film and method of manufacturing the same, and various application devices using the same

A first thin film including at least one transition metal selected from the group consisting of Co, Fe and Ni, and a second thin film including at least one platinum group element selected from the group consisting of Pt and Pd are prepared. Then, a multilayered structure where said first thin film and said second thin film are stacked is formed. Then, the multilayered structure is heated at the same time or after the formation of said multilayered structure, thereby to counter-diffuse constituent elements of said first thin film and said second thin film and alloy said at least one transition metal and said platinum group element.

Method for fabricating a magnetic recording medium

A lattice shaped underlayer made of a ferroelectric material having a piezoelectric effect is formed on a substrate. On the crossing points of the underlayer magnetic films with a magnetoelastic effect are formed. By applying a voltage to the given column and row of the underlayer, the underlayer is stressed at the crossing point. Then the stress is transmitted to the magnetic film on the same crossing point making the magnetization reverse through the magnetoelastic effect, thus, carrying out writing to the MRAM.

Writing method for a magnetic immovable memory and a magnetic immovable memory

The present invention aims to provide an excellent exchange coupling thin film consisting of a completely novel material other than FeMn or NiMn and having excellent corrosion resistance and high resistivity, and a magnetoresistive element and a magnetic head each of which include the exchange coupling thin film. The exchange coupling thin film includes an antiferromagnetic film mainly composed of a crystal phase of a body-centered cubic structure and containing Cr and element M where element M contains at least one element of the 3B group elements in the Periodic Table, or Al, Ga or In, and a ferromagnetic film containing at least one of Fe, Ne, and Co, both films being laminated in contact with each other, wherein magnetic exchange coupling is generated in the interface between the antiferromagnetic film and the ferromagnetic film.

Exchange coupling thin film and magnetoresistive element comprising the

Growing community of inventors

Sendai, Japan

Osamu Kitakami