Identification of defect sites in FeAl by Doppler spectroscopy of core electrons

Doppler spectroscopy of core electrons is used to identify defect sites in the intermetallic compound FeAl. Two-dimensional annihilation spectra were recorded both for elemental Al and Fe and for the intermetallic compound FeAl. Experimental data are compared with calculations based on density functional theory using the generalized gradient approximation (GGA) for the positron annihilation. In accordance with earlier work vacancies are found to be located on the Fe sublattice. The results show that the accuracy achieved, both experimentally and theoretically, is sufficient to distinguish clearly between vacancies on different sublattices. (orig.)