Moessbauer determination of cobalt substitution in iron-based intermetallics

A Moessbauer source technique has been used in studies of cobalt site preferences in the intermetallic compounds Er6Fe23 and Nd2Fe17. Data quality has been improved by the construction of a resonant conversion electron detector. This detector provides a tenfold increase in signal and allows measurements to be made with the source at reduced temperatures. Results for Er6Fe23 show a strong tendency for cobalt to occupy the f2 site and to avoid the f1 site. For Nd2Fe17, our results reveal that cobalt while it occupies preferentially the h and d sites, is almost completely absent from the c site, and it tends to avoid the f site