INVESTIGATION OF NANOCRYSTALLINE FEF2 BY MOSSBAUER-SPECTROSCOPY

The structure of nanocrystalline FeF2 specimens (average crystal size 10 nm, produced by inert gas condensation) was studied by Mössbauer spectroscopy. The spectrum shows a quadrupole distribution. With the assumption of an average value for Q.S. distribution, two doublets were identified having nearly equal isomer shift. One doublet corresponds to bulk FeF2. The second doublet exhibits a broad distribution of quadrupole splittings with an average value of 1.97 mm s-1 and it is suggested to originate from the atoms in the grain boundaries. A similar distribution was noticed in the hyperfine field of nanocrystalline αFe suggesting the non-lattice arrangement of atoms in the grain boundaries of metallic as well as ionic nanocrystalline materials. © 1990.