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.

公开(公告)号：US10886044B2

公开(公告)日：2021-01-05

申请号：US16292681

申请日：2019-03-05

Applicant: TDK CORPORATION

Inventor： Masashi Ito ,  Eiichiro Fukuchi

IPC: H01F1/058 ,  H01F1/053 ,  H01F1/055 ,  C22C38/00

Abstract: A rare earth permanent magnet that is high in residual magnetization and coercivity is obtained and includes R and T. A main phase of crystal grains having an Nd5Fe17 type crystal structure is included. In an X-ray diffraction profile drawn by performing an XRD measurement for a rare earth permanent magnet, peaks of detected intensity are present in specific ranges. In which the detected intensity of the peak with the highest detected intensity in the range of 41.60°

公开(公告)号：US11302465B2

公开(公告)日：2022-04-12

申请号：US16465412

申请日：2017-11-30

Applicant: TDK CORPORATION

Inventor： Ryuji Hashimoto ,  Masashi Ito ,  Eiichiro Fukuchi ,  Yuki Nagamine

IPC: H01F1/057 ,  C22C38/10

Abstract: To provide a rare earth permanent magnet having as a main phase a compound with a Nd5Fe17 crystalline structure having strong coercive force. A rare earth permanent magnet having as a main phase a compound with a Nd5Fe17 crystalline structure, wherein when the composition ratio of the rare earth permanent magnet is expressed as RaT(100-a-b)Cb, where R is one or more rare earth elements requiring Sm, and T is one or more transition metal elements requiring Fe or Fe and Co, a and b satisfy 18