Abstract
Self-consistent equations are presented for the sedimentation of atoms or molecules in multicomponent condensed systems under an acceleration field. The theory is constructed on the basis of a mean-field approximation, the linear phenomenological matrix law with an expression of atom fluxes and the Nernst-Einstein relation. Accordingly, the effects of the self-interaction between the solutes, the density change, the chemical activity, etc., were consistently taken into account. For two- and three-component systems, the diffusion equations were rewritten in simple useful forms. The theory can immediately be used in the conventional ultracentrifuge as used in biochemistry. A numerical analysis at equilibrium of the sedimentation of atoms induced by a centrifugal field was performed for two- and three-component systems, and the final distributions of concentrations and density were given via the external energy under several atomic and chemical conditions in a wide external energy region. The effects of self-interaction between the solutes, the atomic weight or volume, the chemical activities, the cross effect in diffusion coefficients, etc., were discussed. In addition, the realization and potential of the ultracentrifuge science of condensed matter were considered in the light of the analyses. The changes in atomic concentration and density or the crystal chemical instability induced by a strong acceleration field is expected to be applied in fields such as metallurgy, materials science and solid-state chemistry, as well as in biochemistry.