Diffusion of molybdenum in α-iron

Abstract Tracer diffusion coefficient of 99 Mo in α-iron has been determined in the temperature range between 833 and 1163 K by use of a serial sputter-microsectioning technique. The temperature dependence of the diffusion coefficient, D , in the whole temperature range of α-iron across the Curie temperature can be expressed by D= 1.48 +1.51 −0.75 ×10 −2 exp − 282.6±6.4 kJ mol −1 1+ 0.074±0.005 s 2 RT m 2 s − 1 where s is the ratio of spontaneous magnetization at T K to that at 0 K. The factor 0.074 in the above equation is smaller than 0.156 for self-diffusion in α-iron, showing that the influence of the magnetic transformation on the diffusion of molybdenum in α-iron is smaller than that on the self-diffusion as expected from the negative magnetic moment of molybdenum in the lattice of the ferromagnetic iron.