Tdk Corporation

Shogo Kadota

Kenichi Suzuki

Ryuji Hashimoto

Yuji Umeda

Keiji Takeda

Eiichiro Fukuchi

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&#x2264;C3/(C3+C4)&#x2264;0.5 where C3 denotes the number of trivalent Ce atoms and C4 denotes the number of tetravalent Ce atoms.

Rare-earth permanent magnet

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.

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Tokyo, Japan

Shogo Kadota