Ferrite sintered magnet, ferrite particle, bonded magnet and rotating electric machine

Patent metadata

Field	Value
Publication number	US-2020312497-A1
Application number	US-202016825290-A
Country	US
Kind code	A1
Filing date	Mar 20, 2020
Priority date	Mar 27, 2019
Publication date	Oct 1, 2020
Grant date	—

Abstract

Additionally, a content of B is 0.1 to 0.4% by mass in terms of B2O3, a content of Mn is 0.15 to 1.02% by mass in terms of MnO, and a content of Cr is 0.02 to 2.01% by mass in terms of Cr2O3.

First claim

What is claimed is:

1 . A ferrite sintered magnet comprising ferrite phases having a magnetoplumbite type crystal structure,
wherein the ferrite sintered magnet comprises an element R, an element M, Fe, Co, B, Mn and Cr, the element R is at least one element selected from rare earth elements including Y, the element M is at least one element selected from the group consisting of Ca, Sr and Ba, with Ca being an essential element, when an atomic composition of metallic elements is represented by R 1-x M x Fe m-y Co y , x, y and m satisfy formulae (1), (2) and (3):
0.2≤ x≤ 0.8  (1)

0.1≤ y≤ 0.65  (2)

3≤ m< 14  (3),

a content of B is 0.1 to 0.4% by mass in terms of B 2 O 3 , a content of Mn is 0.15 to 1.02% by mass in terms of MnO, and a content of Cr is 0.02 to 2.01% by mass in terms of Cr 2 O 3 .

2 . The ferrite sintered magnet according to claim 1 , wherein the ferrite sintered magnet satisfies formulae (4) and (5):
0.2≤ x≤ 0.55  (4)
7.5< m< 14  (5).

3 . A rotating electric machine comprising the ferrite sintered magnet according to claim 1 .

4 . Ferrite particles comprising ferrite phases having a magnetoplumbite type crystal structure,
wherein the ferrite particles comprise an element R, an element M, Fe, Co, B, Mn and Cr, the element R is at least one element selected from rare earth elements including Y, the element M is at least one element selected from the group consisting of Ca, Sr and Ba, with Ca being an essential element, when an atomic composition of metallic elements is represented by R 1-x M x Fe m-y Co y , x, y and m satisfy formulae (1), (2) and (3):
0.2≤ x≤ 0.8  (1)

0.1≤ y≤ 0.65  (2)

3≤ m< 14  (3),

a content of B is 0.1 to 0.4% by mass in terms of B 2 O 3 , a content of Mn is 0.15 to 1.02% by mass in terms of MnO, and a content of Cr is 0.02 to 2.01% by mass in terms of Cr 2 O 3 .

5 . The ferrite particles according to claim 4 , wherein the ferrite particles satisfy formulae (4) and (5):
0.2≤ x≤ 0.55  (4)
7.5< m< 14  (5).

6 . A bonded magnet comprising the ferrite particles according to claim 4 .

7 . A rotating electric machine comprising the bonded magnet according to claim 6 .

Assignees

• Tdk Corp

Inventors

• Muroya Shogo
• Murakawa Yoshitaka
• Morita Hiroyuki
• Ikeda Masanori

Classifications

• H01F1/11 Primary

  in the form of particles {(for magnetic record carriers G11B5/70626)} · CPC title

• C01P2002/54

  one element only · CPC title

• C01G51/68

  containing rare earths, e.g. (La0.3Sr0.7)CoO3 · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B2235/3262

  Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO · CPC title