抄録
In this paper, the kinetic method was applied to explain quantitatively the thermal diffusion phenomena of molten alloys. The thermal diffusion flow of solute molecule in a binary system can be calculated from the difference of probabilities of migration in the hot and the cold parts respectively. Thus, the heat of transport ε* can be derived in the following formula: & ε^*=Soret coefficient ×RT^2........................ \labele1
& ε^*=ε_d-ε_h\
otagwhere εd and εh are the energy of inhibition at the original position and that of hole formation at the final position of the migrating molecule respectively. To calculate the value of ε*, the Soret coefficient must be determined from experiment. For a dilute solution it may be calculated by the equation Soret coefficient=\fracΔN_sN_oτ........................ \labele2as shown in the previous report by using temperature difference given to the system τ, initial concentration No, and concentration difference at Soret equilibrium ΔNs. If possible, it is desirable that the differential Soret coefficient is obtained. This value can be acquired by the interpolation method. As regards systems satisfying the equation of rate of first order reaction for that of thermal diffusion, the experimental determination becomes very easy. The value of ΔNs required for calculating the Soret coefficient can be represented in the following simple equation when the time ratio t2⁄t1 is chosen experimentally to be 2 in the primary stage regarded as first order reaction, ΔN_s=\frac(ΔN_1)^22ΔN_1-ΔN_2........................ \labele3where ΔN1 and ΔN2 are the concentration difference at time t1 and t2 respectively. As mentioned above, the heat of transport can be determined experimentally from Eq. (1), (2), and (3).
