COMMEMORATIVE LECTURE BY THE FORTY-SECOND GOLD MEDALIST OF THE JAPAN INSTITUTE OF METALS: On the Small Atomic Clusters Dispersed in Solids

摘要

Small dispersed clusters of forging atoms or a foreign structure in the mother phase, appearing as a precursor or a remnant of phase transformation, are treated by a statistical thermodynamic calculation. The entropy of mixing of the clusters and unclustered atoms is formulated and combined with the enthalpy change associated with the cluster froma- tion to find the equilibrium or quasi-equilibrium state of the dispersion of a small particles. It is applied to the cases of the medium range order structure in amorphous alloys, the precursory premartensitic structure, the early stage of aging and precipitation in alloys, etc.