Interfacial reaction rates and free energy of cubic clusters

Joel Lepinoux (1)

1 LTPCM - Laboratoire de thermodynamique et physico-chimie métallurgiques

A new formulation of interfacial reaction rates for clusters in binary alloys is presented. It accounts for the matrix structure and the topological properties of cluster at the atomic scale. It is shown that the probabilities per unit time that a solute atom be captured or released by a cluster are functions of the partition function but also of a transition function. The principles of calculation of these functions are general but only the case of cubic clusters is treated here (results can be used for L12 clusters in f.c.c. matrices). Calculations has been done exactly for small clusters (size<10), then following a Monte Carlo sampling method at intermediate size as a function of temperature and the interaction energy (a material characteristic). Finally, it is shown that generic results can be extrapolated at higher cluster size in a large range of temperature and / or interaction energy.

Mots clés: Physical Sciences

Joel Lepinoux. Interfacial reaction rates and free energy of cubic clusters. Philosophical Magazine, 2004, 85 (30), pp.3585. ⟨10.1080/14786430500228648⟩. ⟨hal-00513559⟩