Abstract
The thermal diffusion phenomenon was applied to molten Sn-Zn alloys. The temperatures were 650° and 400° at the hot and the cold parts respectively and their gradients were held for the horizontal direction. The experimental apparatus and method were the same as the ones used, previously. The results obtained were as follows: (1) The relation between the concentration difference Δn and the concentration of zinc was of the maximum type as shown in Fig. 1. (2) The values of Soret coefficient at the various concentrations of the solute were calculated by using the equation (I). Their magnitudes were about I0−4. (3) The Soret coefficient depends little on the concentration of zinc. Its dependence is very complicated and cannot be shown in a simple formmer. The same fact found also with Sn-Pb alloy. (4) The rate of thermal diffusion could be represented as a type of first order reaction in the ordinary chemical changes. This relation was satisfactorily applied in the dilute solutions, especially at the earlier stages of the thermal diffusion. (5) The values of rate constants k were about I0−1∼I0−2 (hrs−1·unit). The relations between the rate constants and the concentrations of zinc were found to be of the minimum type.
