Ferrite magnet

Patent metadata

Field	Value
Publication number	US-11417447-B2
Application number	US-201716302751-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	May 20, 2016
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A1-xRx(Fe12-yMey)z, (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) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. 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 ferrite phase having a magnetoplumbite structure and an orthoferrite phase, 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), and

0<m<28.0 is satisfied, where m is an orthoferrite-phase content by mol %.

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

• C04B2235/3208

  Calcium oxide or oxide-forming salts thereof, e.g. lime · CPC title

• C01G51/68

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

• C04B2235/3284

  Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof · 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