Localized moment in Mn-doped γ-TiAl alloys

For the γ-phase ${\mathrm{Ti}}_{50\mathrm{-}\mathit{x}}$${\mathrm{Mn}}_{\mathit{x}}$${\mathrm{Al}}_{50}$ alloys (x=0, 0.06, 0.77, 1.85, and 3.30), lattice parameters by x-ray diffraction and temperature dependence (5–300 K) of the magnetic susceptibility are measured. With Mn doping, the tetragonality of the L$1_0$ unit cell of γ-TiAl decreases and a localized moment μ≃2.31${\mathrm{\mu }}_{\mathit{B}}$/Mn atom appears. The results can be explained in terms of Mn substituting for Ti, although a theoretical understanding of the small magnitude of the moment is still lacking.