公开(公告)号：EP2031607A1

公开(公告)日：2009-03-04

申请号：EP07745321.5

申请日：2007-06-08

申请人： DOWA Electronics Materials Co., Ltd.

发明人： ISHIKAWA, Yuzo ,  MASADA, Kenji

IPC分类号： H01F1/09 ,  B22F1/00 ,  C01B21/06 ,  G11B5/712 ,  G11B5/714 ,  H01F1/06

CPC分类号： G11B5/70626 ,  B82Y30/00 ,  C01B21/0622 ,  C01P2004/64 ,  C01P2004/80 ,  C01P2006/42 ,  G11B5/712 ,  G11B5/714 ,  H01F1/065 ,  H01F1/09

摘要： Provided is an iron nitride-based magnetic powder that comprises magnetic particles having a mean particle size of at most 20 nm. The magnetic particle has a core of a main phase of Fe 16 N 2 and has, on the outer side of the core, an oxide phase derived from a metal Fe phase formed by reduction of iron nitride. In relation to the weatherability index Δσs and the saturation magnetization σs thereof, the magnetic powder satisfies Δσs ≤ 0.8 x σs - 30. In this, Δσs = (σs - σs 1 )/σs x 100. σs 1 means the saturation magnetization of the magnetic powder kept in an atmosphere of 60°C and 90 % RH for 1 week. The powder can be obtained by exposing powder particles having a main phase of Fe 16 N 2 to a reducing gas to partly reduce the region of the surface of the particles into a metal Fe phase (gradual reduction) followed by exposing them to an oxidizing gas to oxidize a part of the surface of the metal Fe phase into an oxide phase (gradual oxidation).

摘要翻译： 本发明提供一种含有平均粒径为20nm以下的磁性粒子的氮化铁系磁性粉末。 该磁性颗粒具有Fe 16 N 2主相的芯，并且在芯的外侧具有衍生自通过还原氮化铁形成的金属Fe相的氧化物相。 关于耐候性指数“Ãs和饱和磁化强度”，磁粉满足“ɤ0.8 xâ30”。在这里，“Ãs=（Ãs - Ãs1）/Ãsx 100.Ãs1表示 磁粉的饱和磁化强度保持在60℃，90％RH的气氛中1周。 可以通过将具有Fe 16 N 2主相的粉末颗粒暴露于还原气体来部分地将颗粒表面的区域还原为金属Fe相（逐渐还原），然后将其暴露于氧化气体 以将金属Fe相的一部分表面氧化成氧化物相（逐渐氧化）。

公开(公告)号：EP3385951A1

公开(公告)日：2018-10-10

申请号：EP16870689.3

申请日：2016-11-30

申请人： The University Of Tokyo ,  Dowa Electronics Materials Co., Ltd.

发明人： OHKOSHI, Shin-ichi ,  IMOTO, Kenta ,  ANAN, Shizuka ,  NAMAI, Asuka ,  MASADA, Kenji

IPC分类号： G11B5/706 ,  C01G49/00 ,  C01G55/00 ,  G11B5/02 ,  G11B5/852 ,  H01F1/11

CPC分类号： G11B5/70605 ,  C01G49/00 ,  C01G55/00 ,  C01G55/002 ,  C01P2002/54 ,  C01P2006/42 ,  G11B5/02 ,  G11B5/706 ,  G11B5/852 ,  G11B2005/0024 ,  H01F1/11

摘要： There is provided an oriented body containing platinum group-substituted-ε 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.

公开(公告)号：EP3671778A1

公开(公告)日：2020-06-24

申请号：EP20155615.6

申请日：2016-01-18

申请人： The University of Tokyo ,  DOWA ELECTRONICS MATERIALS CO., LTD.

发明人： OHKOSHI, Shin-ichi ,  TOKORO, Hiroko ,  NAKABAYASHI, Koji ,  NAMAI, Asuka ,  IMOTO, Kenta ,  MASADA, Kenji

IPC分类号： H01F41/16 ,  H01F1/113 ,  C01G49/06 ,  G11B5/706 ,  G11B5/845 ,  H01F1/11

摘要： The present invention relates to a method for producing an oriented body containing ε iron oxide.

公开(公告)号：EP2031607B1

公开(公告)日：2012-03-07

申请号：EP07745321.5

申请日：2007-06-08

申请人： DOWA Electronics Materials Co., Ltd.

发明人： ISHIKAWA, Yuzo ,  MASADA, Kenji

IPC分类号： H01F1/09 ,  B22F1/00 ,  C01B21/06 ,  G11B5/712 ,  G11B5/714 ,  H01F1/06

CPC分类号： G11B5/70626 ,  B82Y30/00 ,  C01B21/0622 ,  C01P2004/64 ,  C01P2004/80 ,  C01P2006/42 ,  G11B5/712 ,  G11B5/714 ,  H01F1/065 ,  H01F1/09

摘要： An iron nitride-based magnetic powder comprising magnetic particles which each has a core consisting mainly of an Fe16N2 phase and further has, outside the core, an oxide phase derived from an iron metal phase resulting from reduction of the iron nitride and which have an average particle diameter of 20 nm or smaller. The iron nitride-based magnetic powder has a weatherability index Δσs and a saturation magnetization σs which satisfy the relationship Δσs≤0.8×σs-30. In the relationship, Δσs is (σs-σs1)/σs×100, provided that σs1 represents the saturation magnetization of the magnetic powder as measured after one-week standing in an atmosphere of 60°C and 90 %RH. This powder can be obtained by exposing powder particles consisting mainly of an Fe16N2 phase to a reducing gas to convert a surface region of each particle to an iron metal phase (gradual reduction treatment) and then exposing them to an oxidizing gas to convert a surface region of the iron metal phase to an oxide phase (gradual oxidation treatment).