Magnetization and Temperature Dependence of the Mössbauer Spectrum Shift for an Insulator

Abstract

The results of a M\"ossbauer-effect study of HoFe${\mathrm{O}}_{3}$ in the temperature range 99-875\ifmmode^\circ\else\textdegree\fi{}K are presented. Special attention is paid to the shift of the center of the spectrum and its temperature dependence both above and below the N\'eel point ${T}_{N}$. Although no discontinuity is found at the N\'eel temperature, the total shift has a different temperature dependence for $T<{T}_{N}$ and for $T>{T}_{N}$. The experimental results are compared with theoretical predictions based on a magnetization-dependent Debye model. Also, a theoretical model based on the supertransferred process is presented which gives rise to a magnetization-dependent isomer shift, although the calculated effect is almost two orders of magnitude too small.