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Title:
RARE EARTH SINTERED MAGNET
Document Type and Number:
Japanese Patent JP2009016403
Kind Code:
A
Abstract:

To provide a rare earth sintered magnet which has high mechanical strength and is not apt to chip.

The rare earth sintered magnet has a surface portion and a center portion enclosed with the surface portion and contains, as a main phase, particles containing an R2T14B-based compound (wherein R includes at least one kind of rare earth element and T represents Fe alone or both Fe and Co), the rare earth sintered magnet being characterized in that when the distance from the surface to the center of gravity of the particles during two-dimensional observation is considered to be 100%, the surface part is a part up to 20% of the distance from the surface toward the center of gravity and when the ratio of the lattice constants of a (c) axis to an (a) axis of the R2T14B-based compound is denoted as c/a, 20% of particles which are 0.5 to 1.4% smaller in c/a at the surface portion than the center portion are contained in all particles sampled during the two-dimensional observation.


Inventors:
HIDAKA TETSUYA
KATO EIJI
Application Number:
JP2007173547A
Publication Date:
January 22, 2009
Filing Date:
June 29, 2007
Export Citation:
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Assignee:
TDK CORP
International Classes:
H01F1/053; H01F1/08
Domestic Patent References:
JP2006210450A2006-08-10
JPH04155902A1992-05-28
Foreign References:
WO2005001856A12005-01-06
WO2006098204A12006-09-21
Attorney, Agent or Firm:
Yoshiki Hasegawa
Shiro Terasaki
Hiroaki Aoki