Positron lifetime measurement on centrifuged BiPb intermetallic compound

Ono, Masao; Huang, X. S.*; Shibata, Yasuhiro*; Iguchi, Yusuke*; Sakai, Seiji; Maekawa, Masaki; Chen, Z. Q.*; Osakabe, Toyotaka; Kawasuso, Atsuo; Naramoto, Hiroshi*; et al.

Proceedings of 1st International Conference on Diffusion in Solids and Liquids (DSL 2005), p.531 - 533, 2005/07

Recently, we formed atomic-scale graded structures in some miscible alloys and observed the decomposition in BiPb intermetallic compound by sedimentation of atoms under strong gravitational field. In this study, we measured positron lifetime of centrifuged BiPb, to which the composition change was very small as it was treated at low temperature. It was found that the positron lifetime became longer than that of starting state. This indicated that the point defects (vacancy or divacancy) increased in the sample by centrifugal treatment. We are now investigating the relationship between increase in point defects and sedimentation of atoms.