NONEQUILIBRIUM PHASE-DIAGRAMS IN THE PBCL2-AGCL EUTECTIC SYSTEM

It is well-known that eutectics do not necessarily grow at the eutecti c temperature, or with the eutectic composition. Thus, the eutectic po int. can be shifted due to nonequilibrium conditions in the system. Th is fact was observed in many experiments. We try to explain this behav iour on base of the study of phase transformation kinetics. We constru ct the kinetic phase diagrams of PbCl2AgCl within the framework as of the nucleation theory as of the theory of growth on the phase interfac e. Our models are based on the molecular model of the difference of ch emical potential of components for the liquid and solid phases. The pr oposed model describes the position of the eutectic point very well an d is practically applied for the study of nonequilibrium directional g rowth in the PbCl2-AgCl system.