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公开(公告)号：US20220081319A1
公开(公告)日：2022-03-17
申请号：US17419346
申请日：2020-02-04
发明人： Shin-ichi OHKOSHI , Asuka NAMAI , Marie YOSHIKIYO , Daisuke KODAMA , Shiho OBATA , Masahiro GOTOH
摘要： An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ε-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.
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公开(公告)号：US20210300779A1
公开(公告)日：2021-09-30
申请号：US16979241
申请日：2019-03-26
发明人： Shin-ichi OHKOSHI , Asuka NAMAI , Kenji SAKANE , Tetsuya KAWAHITO
摘要： [Problem] To provide a method for producing iron based oxide magnetic powder that has a narrow particle size distribution and a small content of fine particles that do not contribute to the magnetic recording characteristics, and consequently has a narrow coercive force distribution and is suitable for the enhancement of the recording density of the magnetic recording medium. [Solution] ε-Type iron based oxide magnetic powder is obtained by a wet method, then a tetraalkylammonium salt as a surface modifier is added to a slurry containing the magnetic powder to make a concentration of 0.009 mol/kg or more and 1.0 mol/kg or less, and simultaneously to make pH of 11 or more and 14 or less, and the slurry is subjected to a dispersion treatment and then classified, so as to provide iron based oxide magnetic powder having a narrow particle size distribution and a narrow coercive force distribution.
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13.发明申请公开(公告)号：US20210012936A1
公开(公告)日：2021-01-14
申请号：US16969839
申请日：2019-02-14
发明人： Shin-ichi OHKOSHI , Asuka NAMAI , Marie YOSHIKIYO , Masahiro GOTOH , Toshihiko UEYAMA , Takayuki YOSHIDA
摘要： There is provided a magnetic material that has an excellent electromagnetic wave absorption performance in a wide frequency range even under low temperature and high temperature environments and that ensures the absorption performance, and provided a magnetic material as a mixture of a magnetic material having positive slope of change in coercive force dependent on temperature, and a magnetic material having negative slope of change in coercive force dependent on temperature.
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14.发明申请公开(公告)号：US20180170767A1
公开(公告)日：2018-06-21
申请号：US15735410
申请日：2016-06-13
发明人： Shin-ichi OHKOSHI , Syunsuke OKA , Asuka NAMAI , Kenji MASADA
摘要： An epsilon iron oxide has an average particle size of 10 to 18 nm, a part of the iron element being substituted with a substitutional element and has a coercive force of 14 kOe or less, wherein a coefficient of variation of the particle size is 40% or less. A method for producing the same, a magnetic coating material and a magnetic recording medium using the epsilon iron oxide, includes depositing a metal compound of a substitutional element on iron oxide hydroxide to thereby obtain iron oxide hydroxide on which the metal compound is deposited; coating the iron oxide hydroxide on which the metal compound is deposited, with silicon oxide to thereby obtain iron oxide hydroxide coated with the silicon oxide; and applying heat treatment to the silicon oxide-coated iron oxide hydroxide in an oxidizing atmosphere, wherein a part of an iron element is substituted with the substitutional element.
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公开(公告)号：US20220375663A1
公开(公告)日：2022-11-24
申请号：US17764229
申请日：2020-09-29
发明人： Shin-ichi OHKOSHI , Asuka NAMAl , Hiroko TOKORO , Marie YOSHIKIYO , Kazuhiro YAMAGA , Yasuto MIYAMOTO , Yuki MINEYAMA , Kenji SAKANE , Tetsuya KAWAHITO
摘要： 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.
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公开(公告)号：US20210151895A1
公开(公告)日：2021-05-20
申请号：US16626181
申请日：2018-06-25
摘要： A radio wave absorber includes a base member, and a radio wave absorption film formed on the base member. The radio wave absorption film includes at least MTC-substituted ε-Fe2O3 and black titanium oxide. The MTC-substituted ε-Fe2O3 is a crystal belonging to the same space group as an ε-Fe2O3 crystal and expressed by ε-MxTiyCoyFe2−2y−xO3 where M is at least one element selected from the group consisting of Ga, In, Al, and Rh, 0
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17.发明申请公开(公告)号：US20180366151A1
公开(公告)日：2018-12-20
申请号：US15780057
申请日：2016-11-30
发明人： Shin-ichi OHKOSHI , Kenta IMOTO , Shizuka ANAN , Asuka NAMAI , Kenji MASADA
摘要： There is provided an oriented body containing platinum group-substituted-6 iron oxide particles typified by Rh-substituted ϵ-iron oxide or Ru-substituted ϵ-iron oxide applicable to MAMR, MIMR, or F-MIMR system, and a technique related thereto, containing platinum group element-substituted ϵ-iron oxide particles in which a part of ϵ-iron oxide is substituted with at least one element of platinum group elements, as magnetic particles wherein the degree of orientation of the magnetic particles defined by the degree of orientation=SQ (direction of magnetization easy-axes)/SQ (direction of magnetization hard-axes) exceeds 5.0, and a coercive force exceeds 31 kOe.
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18.发明申请METHOD FOR IMPROVING COERCIVE FORCE OF EPSILON-TYPE IRON OXIDE, AND EPSILON-TYPE IRON OXIDE 审中-公开改善EPSILON型氧化铁和EPSILON型氧化铁的强化力的方法公开(公告)号：US20160343484A1
公开(公告)日：2016-11-24
申请号：US15231122
申请日：2016-08-08
发明人： Shin-ichi OHKOSHI , Shunsuke SAKURAI , Asuka NAMAI , Sayaka UMEDA , Hiroshi HACHIYA , Kazuyuki MATSUMOTO , Takashi GOTOH
CPC分类号： H01F1/047 , C01G49/0018 , C01G49/06 , C01P2002/50 , C01P2002/52 , C01P2006/42 , C04B35/26 , C04B35/62826 , C04B2235/3217 , C04B2235/3286 , C04B2235/3289 , C04B2235/3418 , C04B2235/761 , H01F1/10
摘要： An epsilon-type iron oxide having an Fe-site that is substituted with a platinum group element, provided that Fe of a D-site of the epsilon-type iron oxide is not substituted with the platinum group element.
摘要翻译： 具有被铂族元素取代的Fe部位的ε型氧化铁，只要ε型氧化铁的D位的Fe未被铂族元素取代。
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公开(公告)号：US20210375314A1
公开(公告)日：2021-12-02
申请号：US17401326
申请日：2021-08-13
发明人： Shin-ichi OHKOSHI , Marie YOSHIKIYO , Kenta IMOTO , Kosuke NAKAGAWA , Asuka NAMAI , Hiroko TOKORO , Makoto NAKAJIMA , Masashi SHIRATA , Kenji NAOI
IPC分类号： G11B11/105 , G11B5/706
摘要： 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.
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公开(公告)号：US20210027806A1
公开(公告)日：2021-01-28
申请号：US17035077
申请日：2020-09-28
摘要： The present invention provides a recording method and a recording device in which information can be easily recorded even in a magnetic recording medium using epsilon iron oxide particles having a high coercive force as a magnetic recording material. A recording device of the invention applies an external magnetic field H0 that inclines magnetization of epsilon iron oxide particles to a particle dispersion element containing epsilon iron oxide particles, and irradiates the particle dispersion element with light that excites the magnetization. Accordingly, the recording device is capable of inverting magnetization that is not capable of being inverted only by the external magnetic field, in accordance with a synergetic effect between the inclination of the magnetization and the light excitation of the magnetization.
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