The University of Tokyo

Dowa Electronics Materials Co., Ltd.

Fujifilm Corporation

Osaka University

Dowa Holdings Co., Ltd.

Hiroko Tokoro

Shin-ichi Ohkoshi

Asuka Namai

Kazuhito Hashimoto

Marie Yoshikiyo

Yoshihide Tsunobuchi

Fumiyoshi Hakoe

Takayuki Yoshida

Manabu Tanaka

Kenta Imoto

Waka Tarora

Kenji Sakane

Masashi Shirata

Kenji Naoi

Kenji Masada

Tetsuya Kawahito

Kazuhiro Yamaga

Tomoyuki Matsuda

Makoto Nakajima

Deepa Dey

Kosuke Nakagawa

Yasuto Miyamoto

Koji Nakabayashi

Yuki Mineyama

Tomomichi Nasu

A raw material solution containing trivalent iron ions, or trivalent iron ions and ions of a metal element that partially substitutes Fe sites, and an alkaline aqueous solution for neutralizing the raw material solution are added to a reaction system to adjust the pH of the reaction system from 1.0 to 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and the pH of the reaction system is then neutralized from 7.0 to 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide, followed by heating so as to form particles of ε-iron oxide in which Fe sites are partially substituted by other metal elements, and then, a slurry containing the particles is classified. The iron-based oxide magnetic powder has a particle shape close to a perfect sphere and is suitable for use in a magnetic recording medium.

Iron-based oxide magnetic powder and method for producing same

Provided is a recording device. The recording device includes: an external magnetic field application unit that is configured to apply an external magnetic field to a magnetic recording medium; a light irradiation unit that is configured to irradiate light; and a light focusing unit that is configured to focus the light from the light irradiation unit by resonating the light to generate an enhanced magnetic field in which a magnetic field of the light is enhanced, in which magnetization of the magnetic recording medium is inverted by applying the external magnetic field and the enhanced magnetic field to the magnetic recording medium.

Recording device and recording method

There are provided an oriented body such as a magnetic sheet in which a value of degree of orientation of magnetic particles is beyond 3.5, and a method for producing the same, and a device for producing the same, wherein the oriented body such as a magnetic sheet is produced through the steps of: mixing a mixed solution containing a solvent and a vehicle and &#x3b5;-iron oxide particles by shaking stirring, and dispersing the &#x3b5;-iron oxide particles in the mixed solution; providing a mixed solution in which the &#x3b5;-iron oxide particles are dispersed, on a predetermined substrate; and removing the solvent while applying a magnetic field to the substrate provided with the mixed solution, to obtain an oriented body.

Oriented body containing  e-iron oxide, method for producing the same, and device for producing the same

A magnetic &#x3c3;-form iron oxide nanopowder is a novel magnetic iron oxide nanopowder having magnetic polarization and spontaneous electric polarization and having physical properties similar to those of half-metals; and a process produces the magnetic nanopowder. The magnetic powder has a composition represented by FeOand has a crystal structure belonging to the monoclinic system.

Magnetic iron oxide nanopowder and process for producing the same

There is provided an iron oxide magnetic nanoparticle powder having a ferromagnetic property even if the particles have an average particle size of 15 nm or less, preferably 10 nm or less, and a method of producing the same, an iron oxide magnetic nanoparticle thin film containing the iron oxide magnetic nanoparticle powder and a method of producing the same, wherein the iron oxide magnetic nanoparticles having an &#x3b5;-FeOsingle phase, having the average particle size of 15 nm or less, and further 10 nm or less, are generated by using &#x3b2;-FeO(OH) (iron oxide hydroxide) nanoparticles as a starting material, and coating the (iron oxide hydroxide) nanoparticles with silicon oxide, and applying heat treatment thereto under an atmospheric air, and further the iron oxide magnetic nanoparticle thin film is obtained by using the iron oxide magnetic nanoparticles.

Iron oxide magnetic nanoparticle powder and method of producing the same, iron oxide magnetic nanoparticle thin film containing the iron oxide magnetic nanoparticle powder and method of producing the same

A titanium oxide particle that can develop non-conventional and novel physical properties, a method for manufacturing the same, and a magnetic memory, an optical information recording medium, and a charge accumulation type memory using the same are provided. A silica-coated titanium hydroxide compound particle is directly produced through a sol-gel technique and not through a reverse micelle technique, and the silica-coated titanium hydroxide compound particle is subjected to a calcination process. Hence, a titanium oxide particlecan be provided which can develop non-conventional and novel physical properties such that it does not perform phase transition at a room temperature and a TiOparticle body can always maintain the characteristic as a paramagnetic metal in all temperature ranges unlike conventional bulk bodies that perform phase transition between a non-magnetic semiconductor and a paramagnetic metal at a temperature near about 460 K.

Titanium oxide particles, process for producing same, magnetic memory, optical information recording medium, and charge accumulation type memory

A microstructure that can develop non-conventional and novel physical properties and a method for producing the same are provided. Ethanol is added to a mixture solution produced by adding a surfactant solution to a peroxotitanic acid aqueous solution to produce precipitates, and the precipitates collected from the mixture solution are let dried to produce precursor powders. The precursor powdersare calcined at a predetermined temperature. Accordingly, a microstructurecan be produced which is formed of monophasic TiOin nano size. The microstructureof monophasic TiOproduced in this fashion can be fine-grained in nano size unlike prior-art crystals.

Microstructure and manufacturing method therefor

There are provided titanium oxide particles capable of manifesting an unprecedented property, a manufacturing method thereof and a magnetic memory as well as a charge storage type memory employing the titanium oxide particles. Unlike-conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, provided are titanium oxide particlescapable of manifesting an unprecedented property that TiOparticles do not undergo phase transitions at room temperature and allow a paramagnetic metal property thereof to be consistently maintained in any temperature range.

Titanium oxide particles, manufacturing method thereof, magnetic memory, and charge storage type memory

There are provided a fine structural body capable of manifesting an unprecedented property; a manufacturing method thereof; and a magnetic memory, a charge storage memory and an optical information recording medium employing such fine structural body. Unlike conventional bulk bodies phase-transited between nonmagnetic semiconductors and paramagnetic metals around about 460K, there can be provided a fine structural bodycomprised of TiO, but capable of manifesting an unprecedented property in which a paramagnetic metal property thereof is consistently maintained in all temperature ranges without undergoing phase transition to a nonmagnetic semiconductor.

Fine structural body, method for manufacturing fine structural body, magnetic memory, charge storage memory and optical information recording medium

Growing community of inventors

Tokyo, Japan

Hiroko Tokoro