Magnetic materials and permanent magnets

  • US 4,770,723 A
  • Filed: 02/10/1987
  • Issued: 09/13/1988
  • Est. Priority Date: 08/21/1982
  • Status: Expired due to Term
First Claim
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1. An anisotropic magnetic material having a mean crystal grain size of at least about 1 micron, an intrinsic coercivity of at least 1 kOe and having a maximum energy product of at least 10 MGOe upon sintering, said material consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire material is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure.

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