A Moessbauer study of the electric hyperfine interaction in K3Fe(CN)6 using polarized gamma radiation

The density matrix formalism is applied to the interpretation of Moessbauer spectra of single crystals of K3Fe(CN)6 taken with polarized γ-radiation to find the average electric hyperfine Hamiltonian of the Moessbauer nucleus. Experimental results are given for 57Fe nuclei in the monoclinic and orthorhombic polytypes. The hyperfine parameters and the orientations of the principal axes vary from one polytype to another. Both polytypes investigated show evidence for more than one inequivalent lattice site, although they are not energetically distinguishable, and an attempt is made in one case to resolve the sites. Some limitations and possible improvements of the accuracy are also discussed