Patent ID: 7338566

Claim:
A method of producing a Sm—Co based magnet alloy consisting of an alloy represented by the formula RM with 32.5 to 35.5 wt % R and the balance of M, wherein R is Sm alone, or Sm in combination with at least one rare earth metal selected from the group consisting of Ce, Pr, Nd, and Gd, M is Co alone, or Co in combination with at least one transition metal, provided that R and M may include inevitable elements, wherein a ratio (B/A) of an X-ray diffraction intensity (B) corresponding to (119) plane of R 2 M 7 phase to an X-ray diffraction intensity (A) corresponding to (111) plane of RM 5 phase is not higher than 0.1, said method comprising cooling an alloy melt of 32.5 to 35.5 wt % raw material alloy for R and the balance of raw material alloy for M from a melting point of said alloy to 800° C. over 0.5 to 20 seconds, and from 800° C. to 200° C. over not less than 600 seconds.