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Ono, Masao; Huang, X.*; Kinoshita, Takahiro*; Ueno, Hideto*; Osakabe, Toyotaka; Mashimo, Tsutomu
Defect and Diffusion Forum, 237-240(2), p.1101 - 1104, 2005/00
Ultra-strong gravitational field can induce sedimentation of even atoms in condensed matter. We had realized sedimentation of substitutional solute atoms in some miscible alloys. How about in the other alloys? So, In this study, the ultra-centrifuge experiments were performed on an intermetallic compound of Bi-Pb system (Bi
Pb
) by changing time duration of experiment time (experimental conditions; maximum centrifugal force: 1.0
10
g level, temperature: 130-150 
C, duration: 30-150h, state: solid). Composition changes were observed in the centrifuged samples. And, it was found that the Bi phase appeared from starting state of BiPb around the weak gravitational field region of the sample. These results showed that sedimentation of substitutional solute atoms occurred, and induced the structure change in intermetallic compounds.
Mashimo, Tsutomu
Defect and Diffusion Forum, 237-240(1), p.30 - 37, 2005/00
Mega-gravity field realizes the sedimentation of even atoms, and is expected to create a nonequilibrium crystal-chemical state in condensed matter. We presented a self-consistent diffusion equation for sedimentation of atoms in condensed matter. Next, we developed an ultracentrifuge to generate strong acceleration field of over 1 million g, and, recently, succeeded in realization of the sedimentation of substitutional solute atoms in some alloys. The diffusion coefficients of sedimentation on Bi-Sb alloy were estimated to be much greater than those of conventional one. It is suggested that the sedimentation of substitutional atoms in solids or liquids can be included in a new type of diffusion, where the diffusion mechanism 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.