Isotope fluctuation in indium-lead alloy induced by solid centrifugation

Ono, Masao  ; Iguchi, Yusuke*; Okayasu, Satoru  ; Esaka, Fumitaka  ; Kobayashi, Katsura*; Hao, T.; Bagum, R.*; Osawa, Takahito  ; Fujii, Kimio; Nakamura, Eizo*; Mashimo, Tsutomu

The atomic-scale graded structure of In-Pb alloy was formed by an ultracentrifuge experiment under conditions that a gravitational field of 810,000 G for 100 hours at 150C (solid state) in our previous study. The isotope fluctuation on this sample was measured using secondary ion mass spectrometer (SIMS). The ratio both Pb/Pb and In/In changed with positive gradient in the direction of centrifugal force approximately 1.2%. These isotope fluctuations were larger than that of starting state of natural state (In0.2%, Pb0.1%). These show that the sedimentation of isotopes occurred by solid centrifugation in this alloy, although achieved concentration gradients were small.