Phenomenological Interpretation of Positron Lifetimes in Metals

Publisher Website
Google Scholar
Abstract
Measurements are made of the angular correlation curves of positron annihilation and the positron lifetimes for fully annealed specimens of Mg, Zn, Cd, Al, In, Sn, Pb, Cu, Ag and Ni to clarify the relationship between Γv (annihilation rate of a positron with conduction electrons) and their density Γo. By use of the usual separation method of the total rate Γ into ΓV and ΓC (with core electrons), the experimental relationship between ΓV and ϱ0is obtained. It is found that (1) the metals are sorted into two groups (A and B groups) according to the dependence of ΓV on ϱ0 (2) A‐group metals (Li, Na, K, Rb, Cs and Mg) obey the theoretical relationship, and (3) however, B‐group metals (Zn, Cd, Al, In, Sn, Pb, Cu, Ag and Ni) do not obey. For this difference between both the groups, a possible explanation is presented and the origin of the difference is attributed to the existence of the spaces in the lattice large enough for a positron to become more or less correlated with a single electron in a quasi‐bound state at the low electronic density limit.

This publication has 14 references indexed in Scilit: