Electronic, Structural, and Magnetic Properties of 57 Fe Atoms Created by 57 Co Electron Capture Decay in CoF 2 and in CoCl 2 − and FeCl 2 − Bispyridine Complexes

A comparative investigation of the 57 Fe absorption and emission spectroscopy data in hosts of CoF 2 , CoCl 2 2py, and FeCl 2 2py is reported in both the paramagnetic and antiferromagnetic phases of these compounds. The electron capture decay products are observed to coexist in the Fe 2+ and Fe 3+ ionic configurations in CoF 2 , while only the Fe 2+ charge state is stabilized inFeCl 2 2py and CoCl 2 2py hosts. Distributions of hyperfine interactions are observed in the complex ligand compounds FeCl 2 2py and CoCl 2 2py, whereas there is no indication for such effects in the monoatomic ligand compound CoF 2 . This indicates unique unperturbed substitutional rest sites in CoF 2 , whereas in the other hosts, part of the decay products are observed in a distribution of defect sites.