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

Patent metadata

Field	Value
Publication number	US-2022319746-A1
Application number	US-202217700954-A
Country	US
Kind code	A1
Filing date	Mar 22, 2022
Priority date	Mar 24, 2021
Publication date	Oct 6, 2022
Grant date	—

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≤ 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

• H02K1/02

  characterised by the magnetic material · CPC title

• C04B35/2641

  Compositions containing one or more ferrites of the group comprising rare earth metals and one or more ferrites of the group comprising alkali metals, alkaline earth metals or lead · CPC title

• C04B35/2633

  containing barium, strontium or calcium · CPC title

• C04B35/2658

  Other ferrites containing manganese or zinc, e.g. Mn-Zn ferrites · CPC title

• C04B35/2666

  Other ferrites containing nickel, copper or cobalt · CPC title