Measurement of Trigonal Field Splitting of ${\mathrm{Fe}}^{2+}$ in Ge${\mathrm{Fe}}_2$${\mathrm{O}}_4$ by the Mössbauer Effect

Mössbauer absorption spectra in Ge${\mathrm{Fe}}_2$ ${\mathrm{O}}_4$ were measured, covering a temperature range from 77 to 1020°K. From a first-order perturbation calculation, the orbital eigenfunctions, as well as the quadrupole splitting as a function of temperature, were determined with the trigonal field splitting $\delta$ as a parameter. By fitting the theoretical expression for the temperature dependence of the quadrupole splitting to the experimental results, $\delta$ was found to be (1650±50)°K.