Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Global Storage Technologies Japan, Ltd.

Kazusuke Yamanaka

Masaaki Futamoto

Nobuyuki Inaba

Tomoo Yamamoto

Yuzuru Hosoe

Yoshibumi Matsuda

Shinji Narishige

Kenji Furusawa

Yasutaro Uesaka

Masukazu Igarashi

Ichiro Tamai

Emi Mangyo

Atsushi Nakamura

Yoshiyuki Hirayama

Yukio Honda

Fumiyoshi Kirino

Kazuetsu Yoshida

Saburo Nonogaki

Akira Ishikawa

Akira Kawakami

Kenya Ito

Tsunemi Ohiwa

Toshikatsu Manabe

Kenichi Yokoyama

Toyoji Okuwaki

Shuichi Wada

Shouji Mochizuki

Hideo Kusada

A magnetic recording medium having a substrate, an under-layer formed on the substrate, a magnetic layer formed on the substrate and a protective layer formed on the magnetic layer. The magnetic layer comprises Co, Cr and Pt with a thickness being from 10 nm to 22 nm. Further, a coercivity of the magnetic layer is not less than 2000 Oe, and a fluctuation field of magnetic viscosity at a field strength equal to remanence coercivity or coercivity is not less than 30 Oe.

Magnetic recording medium and magnetic recording and reproducing apparatus

An ferromagnetic thin film is used to provide a magnetic recording medium whose noise is low and whose S/N value is high. The ferromagnetic thin film as the magnetic film of the magnetic recording medium is such that the fluctuation field of magnetic viscosity at 25&#xb0; C. at the field strength equal to remanence coercivity or coercivity is not less than 15 oersteds and the coercivity is not less than 2000 oersteds.

Magnetic recording medium possessing a fluctuation field of not less than 30 Oe

To obtain a large capacity magnetic recording medium capable of recording at a super high density of 3 Gbit or more per one square inch and a magnetic storage apparatus, a magnetic recording medium is prepared by disposing orientation control layers &prime; having at least a B2 (CsCl) structure on a substrate , disposing a first underlayer comprising Cr and a second underlayer containing at least one element selected from Cr, Nb, Mo, Ta, W and Ti and having a lattice constant greater than that of the first underlayer and then forming a magnetic layer comprising Co as the main ingredient. A magnetic storage apparatus is constituted by combining the magnetic recording medium, a magnetic head comprising a recording system and a read out system opposed to each of the surfaces of the magnetic recording medium, a unit for moving the magnetic head relative to the magnetic recording medium and a read/write signal processing system for waveform processing of input signals and output signals to and from the magnetic head.

Longitudinal magnetic recording media

A thin film magnetic recording medium including a magnetic layer having a fluctuation field defined as S/X , where S is magnetic viscosity and X is irreversible susceptibility X . The fluctuation field of the magnetic layer is not less than 15 oersteds.

Magnetic recording medium and magnetic recording and reproducing apparatus wherein the magnetic layer has a fluctuation of field; A or Hf of not less than 30 Oersteds

A magnetic recording medium has a magnetic recording film in which the magnitude of saturation magnetization Ms(T&equals;5&deg; K) at 5&deg; K and magnitude of saturation magnetization Ms(T&equals;300&deg; K) at 300&deg; K satisfy: Ms(T&equals;300&deg; K)/Ms(T&equals;5&deg; K)&gE;0.75. The recording medium enables the high-density recording, and a magnetic recording apparatus using this recording medium can yield a sufficiently high reproduction signal level within the operating temperature range of the apparatus.

Magnetic recording medium and magnetic recording apparatus

A ferromagnetic thin film is used to provide a magnetic recording medium whose noise is low and whose S/N is high. The ferromagnetic thin film as the magnetic film of the magnetic recording medium is such that the fluctuation field of magnetic viscosity at 25&deg; C. at the field strength equal to remanence coercivity or coercivity is not less than 15 oersteds and the coercivity is not less than 2000 oersteds.

Magnetic thin film magnetic recording medium

A magnetic recording system high in S/N and low in bit error rate, capable of carrying out writing and reading of high recording density of at least 1 gigabit per 1 square inch and high in reliability can be realized by making the magnetic layer of the magnetic recording medium from a mixture comprising at least one non-magnetic compound selected from the group consisting of oxides and nitrides and a magnetic material comprising Co and Pt as main components and specifying the molar ratio of Pt to Co in the magnetic layer, and employing a magnetoresistive read back magnetic recording head.

Magnetic recording system and magnetic recording medium used therefor

A perpendicular magnetic recording medium is provided by using a ferromagnetic polycrystalline thin film having main components of cobalt and chromium in which the coercivity is 1500 oersted or more and the fluctuation field of magnetic viscosity is 30 oersted or more; the film thickness is controlled within a range from 30 nm to 100 nm. A perpendicular magnetic recording medium with low noise and high output which is suited for high density recording can be obtained and a large capacity magnetic recording and reproducing apparatus can be provided by using this medium.

Perpendicular magnetic recording media and magnetic recording and

A magnetic recording medium having an improved S/N is provided by using a ferromagnetic metal thin film having a mean value of a fluctuation field of magnetic viscosithy measured at 25.degree. C. in a region in which an applied magnetic field strength is 0.8 to 1.2 times as large as a remanence coercivity, of between 15 Oersteads and 30 Oersteads, and preferably a coercivity of between 700 Oersteads and 2000 Oersteads.

Magnetic recording medium

An electrochromic display device which comprises a display electrode comprising a transparent substrate, a transparent electrode formed on an inner surface of the transparent substrate and an electrochromic material layer for display made of tungsten oxide and formed on the transparent electrode; a counter electrode comprising a substrate, a conductive layer formed on an inner surface of the substrate and an activated carbon fiber material; and a spacer provided between the display electrode and the counter electrode with their inner surfaces facing each other to define, between them, an electrolyte chamber, which is filled with an electrolyte comprising a lithium salt and at least one of the tertiary alkyl ammonium salts and quarternary alkyl ammonium slats dissolved in a non-aqueous medium containing a small amount of water, which device has increased original injected charge which can last for a long time.

Electrochromic display device

Disclosed is an electrochromic display element having a counter electrode comprised of a sintered material prepared by sintering an atomized material comprising as main components a powder of Sn[Fe(CN).sub.6 ], MnK[Fe(CN).sub.6 ], NiK[Fe(CN).sub.6 ], amorphous Fe.sub.2 (WO.sub.4).sub.3, amorphous FeWO.sub.4, amorphous Mn.sub.2 (WO.sub.4).sub.3 or amorphous MnWO.sub.4 and a powder of carbon. This electrochromic display element is characterized in that no substantial non-uniform brightness is observed among colored segments.

Growing community of inventors

Kanagawa, Japan

Kazusuke Yamanaka