	US 11,810,699 B2
	Ferrite sintered magnet, ferrite particles, bonded magnet, motor, and generator
Junnichi Nagaoka, Tokyo (JP); Hitoshi Taguchi, Tokyo (JP); Yuichi Sugawara, Tokyo (JP); and Jo Sato, Tokyo (JP)
Assigned to TDK Corporation, Tokyo (JP)
Appl. No. 16/469,833
Filed by TDK Corporation, Tokyo (JP)
PCT Filed Dec. 22, 2017, PCT No. PCT/JP2017/046220 § 371(c)(1), (2) Date Jun. 14, 2019, PCT Pub. No. WO2018/117261, PCT Pub. Date Jun. 28, 2018.
Claims priority of application No. 2016-249675 (JP), filed on Dec. 22, 2016.
Prior Publication US 2019/0318856 A1, Oct. 17, 2019
Int. Cl. H01F 1/11 (2006.01); C04B 35/26 (2006.01); C04B 35/626 (2006.01); C04B 35/64 (2006.01); H02K 1/02 (2006.01); H01F 1/113 (2006.01); H01F 1/10 (2006.01)

CPC H01F 1/11 (2013.01) [C04B 35/2633 (2013.01); C04B 35/6262 (2013.01); C04B 35/62625 (2013.01); C04B 35/64 (2013.01); H01F 1/10 (2013.01); H01F 1/113 (2013.01); H02K 1/02 (2013.01); C04B 2235/3274 (2013.01); C04B 2235/3409 (2013.01); C04B 2235/3418 (2013.01); C04B 2235/605 (2013.01); C04B 2235/606 (2013.01); C04B 2235/6567 (2013.01); C04B 2235/76 (2013.01)]

4 Claims

1. A ferrite sintered magnet comprising a ferrite phase having a magnetoplumbite-type crystal structure, wherein

x1, x2, y, and m satisfy the following Equations (6), (7), (8) and (9) when composition of the ferrite sintered magnet is represented by R_1-x1-x2Ca_x1Sr_x2Fe_m-yCo_y, where R denotes at least one kind of element selected from rare earth elements including Y:

0.2≤x1≤0.5 (6)

0≤x2≤0.1 (7)

0.2≤y≤0.4 (8)

6.5≤m≤9.5 (9),

a content of B is from 0.2% to 0.4% by mass or less in terms of B₂O₃, and a content of Si is less than 0.3% by mass when Si is converted into SiO₂, and

wherein a coercive force of the ferrite sintered magnet at 20° C. is 652 Oe or more.