Low background measurements of 1D momentum spectra of the positron annihilation radiation by the coincidence Doppler broadening method were currently used to obtain the quantitative chemical analysis of the environment of vacancy-like defects in supersaturated solid solution of metals. Fractional concentrations were obtained by fitting the coincidence Doppler broadening spectra with linear combination of reference spectra. Examples regarding Al-based alloys were presented to show the quality of the fitting and the consistency of the coincidence Doppler broadening analysis with positron lifetime measurements. The appropriate choice of the references was considered a key factor for reducing systematic errors. Nevertheless the method still required theoretical validation. Preliminary first-principles calculations regarding Cu-decorated vacancies in Al were presented.

Quantitative Chemical Analysis of Vacancy-Solute Complexes in Metallic Solid Solutions by Coincidence Doppler Broadening Spectroscopy. P.Folegati, A.Dupasquier, R.Ferragut, M.M.Iglesias, I.Makkonen, M.J.Puska: Physica Status Solidi C, 2007, 4[10], 3493-6