Identification of vacancies in the ordered intermetallic compound
Click to view
(Color online) (a) Coincident Doppler broadening spectra normalized to the total number of counts of : () after fast cooling from (A), and () after additional annealing at for and slow cooling to room temperature (B). The spectra of pure (dashed line) and of pure, defect free (solid line) are also shown as reference. (b) Ratio curves for (A and B) and to pure, defect-free of the electron momentum distribution derived from the Doppler broadening spectra shown in (a). In the momentum range from 20 to which originates from positron annihilation with core electrons the slope has been emphasized by linear fits through the data. The horizontal slope of in case of high vacancy concentration (A) is a strong indication for an dominated vacancy which is also supported by the coincident Doppler broadening ratio curve additionally shown for with vacancies, measured at (Ref. 13). In case B, the influence from atoms due to partial annihilation in an -environment in the delocalized state is visible from the slightly positive slope.
Click to view
Positron lifetime components with intensities of two specimens with different heat treatments: after fast cooling from ; (A) and after additional annealing at for and slow cooling to room temperature (B). A positron lifetime for the defect-free state is derived from case B.
Article metrics loading...
Full text loading...