Fluorination of the parent oxide, BaFeO3-delta, with polyvinylidine fluoride gives rise to a cubic compound with a = 4.0603(4) angstrom at 298 K. Fe-57 Mossbauer spectra confirmed that all the iron is present as Fe3+. Neutron diffraction data showed complete occupancy of the anion sites, indicating a composition BaFeO2F, with a large displacement of the iron off-site. The magnetic ordering temperature was determined as T-N=645 +/- 5 K. Neutron diffraction data at 4.2 K established G-type antiferromagnetism with a magnetic moment per Fe3+ ion of 3.95 mu(B). However, magnetisation measurements indicated the presence of a weak ferromagnetic moment that is assigned to the canting of the antiferromagnetic structure. Fe-57 Mossbauer spectra in the temperature range 10-300 K were fitted with a model of fluoride ion distribution that retains charge neutrality of the perovskite unit cell.
- oxide fluoride
- canted antiferromagnet