Electric field gradients in normal spinels

Abstract

Abstract The origin of the quadrupole splittings observed in the Mössbauer spectra of the normal spinels ZnFe2O4 and CdFe2O4 has been investigated using a point charge model. The magnitude of the electric field gradient at the octahedral sites is very sensitive to the value of u, the distortion parameter of the anion sub-lattice. Induced dipole moments on the O2- ions have a substantial effect on the magnitude of the quadrupole splitting. The calculations, combined with the experimental results, are used to deduce information about the relative amounts of distortion in the two compounds.