Patent ID: 7208097

Claim:
An iron-based rare earth alloy nanocomposite magnet having a composition represented by the general formula: (Fe 1-m T m ) 100-x-y-z Q x R y Ti z , where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; and R is at least one rare earth element including no La or Ce, the mole fractions x, y, z and m satisfying the inequalities of: 10 at %<x≦17 at %; 7 at %≦y<10 at %; 0.5 at %≦z≦6 at %; and 0≦m≦0.5, respectively; wherein crystal grains of an R 2 T 14 Q type compound have an average grain size of about 20 nm to about 200 nm; crystal grains of a ferromagnetic iron-based boride have an average crystal grain size smaller than the crystal grain size of the crystal grains of the R 2 T 14 Q type compound; and the ferromagnetic iron-based boride is a soft magnetic phase and is dispersed in the grain boundary or present in the form of a film over the grain boundary to cover at least partially the surfaces of the crystal grains of the R 2 T 14 Q type compound.