ADSORPTION OF ALKYLAMINES ON IRON - ENERGETICS OF ADSORPTION BY CONTACT-ANGLE METHOD

Current theories on solidification of pure metals calculate equilibrium surface roughness (i. e. faceted-non faceted transition) by use of an energetic parameter 0t, proportional to the entropy of fusion of pure metal. Present study, which makes use of a statistical thermodynamical treatment, bases the estimation of 0t on experimental values of interface tension; this results in a closer agreement of theory to experience, in particular in the case of semi-metals where precedent treatments failed. Values of a three times larger, in average, than corresponding values based on entropy of fusion have been obtained. For some metals the critical value above which faceting occurs is so nearly reached, explaining how even small additions of a second element to liquid phase may cause, as experience shows, faceted growth.