Patent ID: 7569115

Claim:
Assemblages of particles of a magnetic alloy represented by the formula [T X M 1-X ] containing T and M in a composition ratio where X in the formula is in the range from 0.3 or greater to 0.7 or less, where T is one or two members of the group consisting of Fe and Co and M is one or two members of the group consisting of Pt and Pd, and metallic elements other than T and M that constitute no more than 30 at. % (including 0 at. %) of (T+M) as a percentage of atoms, and the remainder consists of impurities that are unavoidable from a production standpoint, wherein: said assemblages of magnetic alloy particles are such that: A. the face-centered tetragonal fraction is 10-100%, B. the average grain size as measured by TEM observation (D TEM ) is in the range from 5-30 nm, C. the x-ray crystal grain size derived by x-ray diffraction (D X ) is no less than 4 nm, D. the particles of the size D TEM above are dispersed from each other at a distance, and E. 95 or more out of 100 particles satisfy the conditions of Equation (1) below, and Equation (2) is also satisfied; 0.90 X av ≦X 1 , X 2 , . . . X 100 ≦1.10 X av (1) standard deviation sigma of X 1 , X 2 , . . . X 100 20% (2) here, X av represents the value of X in the composition formula [T X M 1-X ] as actually measured in the assemblage of particles (the value of X in the average composition of the particle assemblage), and X 1 , X 2 , . . . X 100 represent the values of X in the composition formula measured in individual particles in TEM-EDX measurement of the assemblages, for each of 100 particles X n selected arbitrarily when 1000 particles are in the field of view of measurement, wherein each particle has fluidity in the state of being dispersed at a distance from each other.