Ferrite magnet

Patent metadata

Field	Value
Publication number	US-2019122792-A1
Application number	US-201716302704-A
Country	US
Kind code	A1
Filing date	May 19, 2017
Priority date	May 20, 2016
Publication date	Apr 25, 2019
Grant date	—

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) A 1-x R x (Fe 12-y Me y ) z , the Fe 2+ 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

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):
0.60≤ x≤ 0.84  (2);

0.30≤ y≤ 0.60  (3);

0.80≤ z< 1.10  (4);

1.60≤ x/yz< 4.00  (5), and

a Fe 2+ content of the ferrite magnet is more than 0.1 mass % and less than 5.4 mass %.

2 . The ferrite magnet according to claim 1 , further comprising Si, wherein a Si content is more than 0.002 mass % and less than 0.15 mass % in terms of SiO 2 .

Assignees

• Tdk Corp

Inventors

• Nagaoka Junnichi
• Taguchi Hitoshi

Classifications

• H01F1/11 Primary

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

• C04B35/26

  based on ferrites · CPC title

• H01F1/0315

  Ferrites · CPC title

• C01G49/0018

  Mixed oxides or hydroxides, (C01G49/0009 takes precedence) · CPC title

• C01G49/0054 Primary

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