The tracer diffusion coefficients of 54Mn in γ-TiAl containing 54.1at%Al were determined at 1095 to 1470K. The species exhibited a linear Arrhenius

behavior, as described by:

D(m2 /s) = 1.2  x  10−3 exp[-326( kJ/mol)/RT] 

It was concluded that impurity diffusion in γ-TiAl occurred by migration of thermal vacancies via nearest-neighbour or next-nearest neighbour jumps.

G.P.Tiwari, Y.Iijima, C.G.Lee, B.H.Koo: Philosophical Magazine, 2011, 91[5], 751-71