The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 22, 2020

Filed:

Mar. 29, 2018
Applicant:

Tdk Corporation, Tokyo, JP;

Inventors:

Keiji Takeda, Tokyo, JP;

Shota Miyazaki, Tokyo, JP;

Assignee:

TDK CORPORATION, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F 1/057 (2006.01); H01F 7/02 (2006.01); B22F 3/10 (2006.01); C22C 38/00 (2006.01); C22C 38/10 (2006.01);
U.S. Cl.
CPC ...
H01F 1/057 (2013.01); C22C 38/005 (2013.01); C22C 38/10 (2013.01); H01F 1/0577 (2013.01); H01F 7/02 (2013.01); C22C 2202/02 (2013.01);
Abstract

An object of the present invention is to provide an R-T-B based permanent magnet having a low coercive force and a low magnetizing field, and having a high residual magnetic flux density and a high minor curve flatness even in the low magnetizing field. Provided is an R-T-B based permanent magnet including a main phase including a compound having an RTB type tetragonal structure and a grain boundary phase existing between the main phases, in which R is at least one rare earth element including scandium and yttrium, T is at least one transition metal element including iron, or at least two transition metal elements including iron and cobalt, the grain boundary includes an R-T-B—C based compound having a higher R concentration, B concentration and C concentration than that of the main phase and having a lower T concentration than that of the main phase.


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