J. Dryzek, DIFFUSION TRAPPING MODEL FOR POSITRONS TRAPPED AT RANDOMLY DISTRIBUTED THERMAL VACANCIES IN METAL, Physica status solidi. b, Basic research, 209(1), 1998, pp. 3-10
The paper presents the exact solution of the one-dimensional diffusion
trapping model (DTM) for trapping of positrons at vacancies. The expl
icit expressions are given for the positron lifetime spectrum and for
the mean positron lifetime within this model, which were applied to th
e description of the positron annihilation measurement with thermally
generated vacancies. The values for the vacancy formation energy obtai
ned from this model were equal to (0.51 +/- 0.005) eV for Pb and (0.48
+/- 0.016) eV for Cd. They are a bit smaller than those obtained for
the standard positron trapping model and correspond well to the values
obtained by other absolute methods.