A comparative study of the diffusion processes in liquid binary alloys with a tendency to aggregation and segregation

In this contribution we report the results of a molecular dynamics study of diffusion processes in liquid potassium-caesium alloys which exhibit a wea k preference towards association. A comparison with the dynamic picture fou nd in alloys with demixing tendency, potassium-sodium, shows that the net d ynamic cross correlations in both systems of alloys are brought about by th e distinct velocity correlation function of the light component. Thermodyna mic and dynamic criteria of non-ideality both indicate a weak tendency towa rds aggregation for all three compositions of K-Cs alloys studied.