Ferrite magnet

Patent metadata

Field	Value
Publication number	US-11569013-B2
Application number	US-201716302704-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	May 20, 2016
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A1-xRx(Fe12-yMey)z, the Fe2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.

First claim

The invention claimed is:

1. A ferrite magnet comprising a magnetoplumbite structure, wherein
a constitutional proportion of metal elements of A, R, Fe, and Me is represented by a formula (1) of A 1-x R x (Fe 12-y Me y ) z , where A is at least one element selected from Sr, Ba, Ca, and Pb, R is at least one element selected from rare earth elements (including Y) and Bi and R at least includes La, and Me is Co or Co and Zn,
x, y, and z of the formula (1) satisfy the following formulae (2), (3), (4), and (5):
0.71≤ x≤ 0.84  (2);

0.30≤ y≤ 0.60  (3);

0.80≤ z≤ 1.10  (4);

1.60< x/yz< 4.00  (5),

a Fe 2+ content of the ferrite magnet is more than 0.1 mass % and less than 5.4 mass %,
a residual magnetic flux density (Br) of the ferrite magnet is 4.7 (kG) or more, and
the ferrite magnet further comprises Si, wherein a Si content is more than 0.03 mass % and less than 0.11 mass % in terms of SiO 2 .

2. The ferrite magnet according to claim 1 , wherein A is at least Sr.

3. The ferrite magnet according to claim 1 , wherein 0.76≤x≤0.84.

4. The ferrite magnet according to claim 1 , wherein 0.76≤x≤0.81.

5. The ferrite magnet according to claim 1 , wherein 0.30≤y≤0.55.

6. The ferrite magnet according to claim 1 , wherein 0.30≤y≤0.51.

7. The ferrite magnet according to claim 1 , wherein 0.34≤y≤0.51.

8. The ferrite magnet according to claim 1 , wherein 0.80≤z≤1.04.

9. The ferrite magnet according to claim 1 , wherein 0.84≤z≤1.04.

10. The ferrite magnet according to claim 1 , wherein 0.84≤z≤1.00.

11. The ferrite magnet according to claim 1 , wherein 1.62≤x/yz≤2.97.

12. The ferrite magnet according to claim 1 , wherein 1.75≤x/yz≤2.97.

13. The ferrite magnet according to claim 1 , wherein 1.75≤x/yz≤2.62.

14. The ferrite magnet according to claim 1 , wherein Fe 2+ content is 0.5 to 5.0 mass %.

15. The ferrite magnet according to claim 1 , wherein Fe 2+ content is 0.5 to 4.4 mass %.

16. The ferrite magnet according to claim 1 , wherein Fe 2+ content is 1.4 to 4.4 mass %.

17. The ferrite magnet according to claim 1 , wherein Si content is 0.03 to 0.09%, in terms of SiO 2 .

Assignees

• Tdk Corp

Inventors

• Nagaoka Junnichi
• Taguchi Hitoshi

Classifications

• C04B2235/604

  Pressing at temperatures other than sintering temperatures · CPC title

• C04B35/62645

  Thermal treatment of powders or mixtures thereof other than sintering · CPC title

• C04B2235/3298

  Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate · CPC title

• C04B2235/3296

  Lead oxides, plumbates or oxide forming salts thereof, e.g. silver plumbate · CPC title

• C01G49/0054 Primary

  containing one rare earth metal, yttrium or scandium · CPC title