Ferrite sintered magnet, ferrite particles, bonded magnet, and rotating electrical machine

Patent metadata

Field	Value
Publication number	US-11699540-B2
Application number	US-202217700954-A
Country	US
Kind code	B2
Filing date	Mar 22, 2022
Priority date	Mar 24, 2021
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

The magnet is a ferrite sintered magnet containing a ferrite phase having a magnetoplumbite-type crystal structure. The ferrite sintered magnet contains at least Ca, a metal element A, a metal element R, Bi, Fe, and a metal element M. The metal element A is at least one kind of element selected from the group consisting of Sr, Ba, and Pb, the metal element R is at least one kind of element selected from the group consisting of rare-earth elements including Y and essentially includes La, the metal element M is at least one kind of element selected from the group consisting of Co, Ni, Zn, Al, Cu, and Cr, and essentially includes Co, and when an atonic ratio of the metal elements is expressed by Formula (1), c, a, r, b, f, and m in Formula (1) satisfy the following Expressions (2) to (8).

First claim

What is claimed is:

1. A ferrite sintered magnet containing a ferrite phase having a magnetoplumbite-type crystal structure, containing:
at least Ca, a metal element A, a metal element R, Bi, Fe, and a metal element M,
wherein the metal element A is at least one kind of element selected from the group consisting of Sr, Ba, and Pb,
the metal element R is at least one kind of element selected from the group consisting of rare-earth elements including Y and essentially includes La,
the metal element M is at least one kind of element selected from the group consisting of Co, Ni, Zn, Al, Cu, and Cr, and essentially includes Co, and
when an atomic ratio of the metal elements is expressed by Formula (1), c, a, r, b, f, and m in Formula (1) satisfy the following Expressions (2) to (8),
Ca c A a R r Bi b Fe f M m   (1)

0.15 ≤c ≤0.5  (2)

0.01 ≤a ≤0.1  (3)

0.45 <r ≤0.80  (4)

0.01 ≤b <0.1  (5)

9.35 <f <11.90  (6)

0.1 ≤m ≤0.50  (7)

c+a+r+b =1  (8)

2. The ferrite sintered magnet according to claim 1 , further satisfying the following Expressions (3-1), (5-1), (6-1), and (7-1),
0.03≤ a ≤0.05  (3-1)

0.01 ≤b ≤0.05  (5-1)

9.35 <f ≤11.25  (6-1)

0.25:5 ≤m ≤0.45  (7-1)

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

4. A rotating electrical machine comprising:
the ferrite sintered magnet according to claim 2 .

5. Ferrite particles containing a ferrite phase having a magnetoplumbite-type crystal structure, containing:
at least Ca, a metal element A, a metal element R, Bi, Fe, and a metal element M,
wherein the metal element A is at least one kind of element selected from the group consisting of Sr, Ba, and Pb,
the metal element R is at least one kind of element selected from the group consisting of rare-earth elements including Y and essentially includes La,
the metal element M is at least one kind of element selected from the group consisting of Co, Ni, Zn, Al, Cu, and Cr, and essentially includes Co, and
when an atomic ratio of the metal elements is expressed by Formula (1), c, a, r, b, f, and m in Formula (1) satisfy the following Expressions (2) to (8),
Ca c A a R r Bi b Fe f M m   (1)

0.15 ≤c <0.5  (2)

0.01≤ a ≤0.1  (3)

0.45 <r ≤0.80  (4)

0.01 ≤b <0.1  (5)

9.35 <f <11.90  (6)

0.1 ≤m ≤0.50  (7)

c+a+r+b =1  (8)

6. A bonded magnet containing:
the ferrite particles according to claim 5 ; and
a resin.

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

Assignees

• Tdk Corp

Inventors

• Ohmura Masashi

Classifications

• H01F1/113 Primary

  in a bonding agent · CPC title

• C01G51/70

  containing rare earths, e.g. LaCoO3  (C01G51/68 takes precedence) · CPC title

• C08K2003/2289

  of cobalt · CPC title

• C08K2201/01

  Magnetic additives · CPC title

• C08K3/22

  of metals · CPC title