公开(公告)号：US10529474B2

公开(公告)日：2020-01-07

申请号：US15304193

申请日：2015-03-10

Applicant: TDK CORPORATION

Inventor： Shogo Kadota ,  Kenichi Suzuki ,  Yuji Umeda ,  Ryuji Hashimoto ,  Keiji Takeda

IPC: H01F1/055 ,  B22F3/16 ,  H01F1/058 ,  H01F1/059 ,  H01F1/057 ,  C22C38/00

Abstract: To provide a permanent magnet which uses Ce of an abundant resource and has a great magnetic anisotropy in rare earth permanent magnets. To obtain a permanent magnet having a high magnetic anisotropy due to the trivalent Ce state by setting the abundance ratio C3/(C3+C4) in the main phase grains to be 0.1≤C3/(C3+C4)≤0.5 where C3 denotes the number of trivalent Ce atoms and C4 denotes the number of tetravalent Ce atoms.

公开(公告)号：US10170225B2

公开(公告)日：2019-01-01

申请号：US15135337

申请日：2016-04-21

Applicant: TDK CORPORATION

Inventor： Kenichi Suzuki ,  Shogo Kadota ,  Eiichiro Fukuchi

IPC: H01F1/00 ,  H01F1/03 ,  H01F10/26 ,  H01F7/02 ,  H01F10/16 ,  C22C38/10 ,  H02K1/02 ,  H01F1/047 ,  H01F41/18

Abstract: A permanent magnet having a periodic structure with the concentrations of Fe and T (T is one or more transition metal elements with Co or Ni as necessity) changing alternately, wherein, the concentrations change with a period of 3.3 nm or less and the concentration difference of Fe in the concentration change is 5 at % or more. The permanent magnet has a high saturation magnetization Is and coercivity HcJ and can be prepared even without rare earth element(s) R.