Sedimentation of Substitutional Solute Atoms in Condensed Matter: New Type of Diffusion
Ultra-strong gravitational field (Mega-gravity field) causes the sedimentation of even atoms (diffusion), and is expected to create a nonequilibrium crystal-chemical state in multi-component condensed matter. However, the materials science research under mega-gravity field has now remained as an unexploited field, while the sedimentation of molecules or polymer had been used in biochemistory. We presented a self-consistent diffusion equation for sedimentation of atoms in condensed matter. Next, we developed an ultracentrifuge apparatus to generate strong acceleration field of over 1 million (1x106) g at temperature range up to 〜300 °C, and, recently, succeeded in realization of the sedimentation of substitutional solute atoms in some alloys of Bi-Sb, In-Pb, Bi-Pb systems, etc. The diffusion coefficients in sedimentation on Bi-Sb alloy were estimated to be much greater than those at normal conditions by a factor of >20. It is suggested that the sedimentation of substitutional atoms in solids or liquids can be explained in a new type of diffusion, where the diffusion mechanism for substitutional solute atoms was yet unknown. In this article, the recent progress in the investigation of sedimentation of atoms under mega-gravity field is reviewed, and the diffusion mechanism is discussed. The application of the mega-gravity field is also discussed.
M. Danielewski, R. Filipek, R. Kozubski, W. Kucza, P. Zieba, Z. Zurek
T. Mashimo "Sedimentation of Substitutional Solute Atoms in Condensed Matter: New Type of Diffusion", Defect and Diffusion Forum, Vols. 237-240, pp. 30-37, 2005