Ferrite sintered magnet

Patent metadata

Field	Value
Publication number	US-2021296030-A1
Application number	US-202117198542-A
Country	US
Kind code	A1
Filing date	Mar 11, 2021
Priority date	Mar 23, 2020
Publication date	Sep 23, 2021
Grant date	—

Abstract

A ferrite sintered magnet including 0.010 mass % or more and 0.090 mass % or less of Mg in terms of MgO.

First claim

What is claimed is:

1 . A ferrite sintered magnet comprising 0.010 mass % or more and 0.090 mass % or less of Mg in terms of MgO.

2 . The ferrite sintered magnet according to claim 1 comprising Ca, R, A, Fe and Co in an atomic ratio of Ca 1-w-x R w A x Fe z Co m , wherein
R includes La only or includes La and at least one selected from rare earth elements,
A is at least one selected from Ba and Sr,
0.364≤w≤0.495,
0.038≤x≤0.136,
8.280≤z≤10.45 and
0.257≤m≤0.338.

3 . The ferrite sintered magnet according to claim 1 comprising Ca, R, A, Fe and Co in an atomic ratio of Ca 1-w-x R w A x Fe z Co m , wherein
R includes La only or includes La and at least one selected from rare earth elements,
A is at least one selected from Ba and Sr,
0.459≤w≤0.474,
0.054≤x≤0.120,
9.837≤z≤9.934 and
0.293≤m≤0.311.

4 . The ferrite sintered magnet according to claim 1 , comprising Ca, R, A, Fe and Co, wherein
R includes La only or includes La and at least one selected from rare earth elements, A is at least one selected from Ba and Sr, Ca is 2.505 mass % or more and 2.951 mass % or less in terms of CaO, R is 8.028 mass % or more and 8.239 mass % or less in terms of R 2 O 3 , A is 0.666 mass % or more and 1.666 mass % or less in terms of AO, Fe is 84.564 mass % or more and 84.937 mass % or less in terms of Fe 2 O 3 , and Co is 2.341 mass % or more and 2.521 mass % or less in terms of CoO.

5 . The ferrite sintered magnet according to claim 1 , comprising 0.005 mass % or more and 0.058 mass % or less of B in terms of B 2 O 3 .

6 . The ferrite sintered magnet according to claim 1 , comprising 0.049 mass % or more and 0.065 mass % or less of Al in terms of Al 2 O 3 .

7 . The ferrite sintered magnet according to claim 1 , comprising 0.315 mass % or more and 0.353 mass % or less of Si in terms of SiO 2 .

8 . The ferrite sintered magnet according to claim 1 , comprising 0.288 mass % or more and 0.341 mass % or less of Mn in terms of MnO.

Assignees

• Tdk Corp

Inventors

• Morita Hiroyuki
• Ikeda Masanori
• Murakawa Yoshitaka
• Muroya Shogo

Classifications

• C01G49/0054

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

• H01F1/11 Primary

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

• C01G49/06

  Ferric oxide [Fe2O3] · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2004/60

  Particles characterised by their size · CPC title