公开(公告)号：US20190318856A1

公开(公告)日：2019-10-17

申请号：US16469833

申请日：2017-12-22

Applicant: TDK Corporation

Inventor： Junnichi NAGAOKA ,  Hitoshi TAGUCHI ,  Yuichi SUGAWARA ,  Jo SATO

IPC: H01F1/11 ,  H02K1/02 ,  C04B35/26 ,  C04B35/626 ,  C04B35/64

Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2≤x≤0.8  (1) 0.1≤y≤0.65  (2) 3≤m

公开(公告)号：US20190267167A1

公开(公告)日：2019-08-29

申请号：US16282466

申请日：2019-02-22

Applicant: TDK Corporation

Inventor： Junnichi NAGAOKA ,  Hiroyuki ONO ,  Yuichi SUGAWARA

IPC: H01F1/11 ,  H01F41/02 ,  C04B35/26

Abstract: A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.

公开(公告)号：US20230290547A1

公开(公告)日：2023-09-14

申请号：US18199721

申请日：2023-05-19

Applicant: TDK Corporation

Inventor： Junnichi NAGAOKA ,  Hitoshi TAGUCHI ,  Yuichi SUGAWARA ,  Jo SATO

IPC: H01F1/11 ,  C04B35/26 ,  C04B35/626 ,  C04B35/64 ,  H02K1/02 ,  H01F1/113 ,  H01F1/10

CPC classification number: H01F1/11 ,  C04B35/2633 ,  C04B35/6262 ,  C04B35/62625 ,  C04B35/64 ,  H02K1/02 ,  H01F1/113 ,  H01F1/10 ,  C04B2235/3274 ,  C04B2235/3409 ,  C04B2235/3418 ,  C04B2235/605 ,  C04B2235/606 ,  C04B2235/6567 ,  C04B2235/76

Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3.


0.2≤x≤0.8  (1)



0.1≤y≤0.65  (2)



3≤m≤14  (3)

公开(公告)号：US20190267168A1

公开(公告)日：2019-08-29

申请号：US16282619

申请日：2019-03-29

Applicant: TDK Corporation

Inventor： Junnichi NAGAOKA ,  Hiroyuki ONO ,  Yuichi SUGAWARA

IPC: H01F1/11 ,  C04B35/26 ,  C04B35/64

Abstract: Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.