Structural characterization study of nickel ferrite particles dispersed in a corrosion product deposit layer

Using X-ray absorption fine structure spectroscopy, both EXAFS and XANES, the cation distributions in NiFe2O4 particles dispersed in a corrosion product deposit layer have been studied. The specimen was obtained from a selected fuel rod used in a commercial boiling water reactor plant. EXAFS data allowed the quantitative determination of specific site distributions for all transition metal cations in Ni-ferrite deposits. The results show that the analyzed NiFe2O4 particles do not have a totally inverted spinel structure. The relative occupancy of iron and nickel cations in the tetrahedral and octahedral sites of the spinel lattice is determined from the measured data.