公开(公告)号：US20220157498A1

公开(公告)日：2022-05-19

申请号：US17598508

申请日：2020-03-27

Applicant: TDK Corporation

Inventor： Masashi OHMURA ,  Junichi NAGAOKA ,  Shogo MUROYA ,  Takuma ABE ,  Jo SATO

IPC: H01F1/11 ,  C01G49/00 ,  C04B35/26

Abstract: A ferrite sintered magnet has a ferrite phase having a magnetoplumbite-type crystal structure, and contains at least a metal element A, a metal element R, Fe, Co, Zn, and B. The element A is at least one kind of element selected from the group consisting of Sr, Ba, Ca, and Pb, and essentially includes Ca. The element R is at least one kind of element selected from the group consisting of Bi and rare-earth elements including Y, and essentially includes La. Atomic ratios of the metal elements satisfy the following expressions. A1-rRrFexCoyZnz  (1) 0.40≤r≤0.70  (2) 8.20≤x≤9.34  (3) 0.05

公开(公告)号：US20240177896A1

公开(公告)日：2024-05-30

申请号：US18283739

申请日：2022-03-24

Applicant: TDK CORPORATION

Inventor： Shogo MUROYA ,  Yoshitaka MURAKAWA ,  Hiroyuki MORITA ,  Masanori IKEDA ,  Takuma ABE

IPC: H01F1/03 ,  H01F1/11

CPC classification number: H01F1/0315 ,  H01F1/11

Abstract: A ferrite sintered magnet represented by A1−xRx(Fe12−yCoy)zO19 in terms of atomic number ratio. A is at least one selected from a group made of Sr, Ba and Pb. R is La only or La and at least one selected from a group made of Bi and rare earth elements. 0.14≤x≤0.22, 11.60≤(12−y)×z≤11.99, and 0.13≤y×z≤0.17 are satisfied. 0.500≤Mc≤0.710 is satisfied in which Mc is CaO content in mass % converted from a content of Ca included in the ferrite sintered magnet. 0.410≤Ms≤0.485 is satisfied in which Ms is SiO2 content in mass % converted from a content of Si included in the ferrite sintered magnet.