Crystal-Field Studies of Fe2+ in FeNb2O6 by the Mössbauer Effect

Abstract

Mössbauer absorption spectra in Fe${\mathrm{Nb}}_2$ ${\mathrm{O}}_6$ were measured over a temperature range from 25 to 950°K. Assuming a certain orbital-level scheme, the effect of the spin-orbit interaction on the eigenfunctions and on the energy levels was calculated. The results obtained were used to calculate the temperature dependence of the quadrupole splitting of the Mössbauer line, with the crystal-field splitting $\delta$ as one parameter and the spin-orbit coupling $\lambda$ as another. By fitting the theoretical expression to the experimental results we get: $\delta =(520\mathrm{}\pm 20)$°K, $\lambda =(-90\mathrm{}\pm 10)$°K.