“…(27,29) There are many experimental results, either for a very limited range of zinc concentration or for temperatures higher or lower than the temperature of the experiments carried out, i.e. T = 903 K. (7,10,11,15,16,24,27,35) The experiments for the widest range of concentration of Zn and for temperatures near T = 903 K were carried out by Ptak (11) (for T = 950 K) and Mu¨ller (26) T = (723 to 973) K. The equation proposed by Ptak (11) is as follows:…”