Patents Represented by Law Firm Oblan, Spivak, McClelland, Maier & Neustadt, P.C.
  • Patent number: 5750044
    Abstract: A magnet consists essentially of 4-8 at % of R, 10-20 at % of N, 2-10 at % of M, and the balance of T wherein R is at least one rare earth element, Sm being present in R in a proportion of at least 50 at %, T is Fe or Fe and Co, M is Zr with or without partial replacement by at least one element of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C, and P. Contained in the magnet are a hard magnetic phase based on R, T, and N and containing at least one crystalline phase selected from TbCu.sub.7, Th.sub.2 Zn.sub.17, and Th.sub.2 Ni.sub.17 types and a soft magnetic phase consisting of a T phase having a bcc structure, the soft magnetic phase having a mean grain size of 5-60 nm and being present in a proportion of 10-60% by volume. This construction ensures high coercivity, high squareness ratio, and high maximum energy product.
    Type: Grant
    Filed: July 11, 1995
    Date of Patent: May 12, 1998
    Assignee: TDK Corporation
    Inventors: Tetsuhito Yoneyama, Tomomi Yamamoto, Tetsuya Hidaka, Akira Fukuno