Mossbauer effect studies on ZnCr_xFe_2-xO₄

Abstract

Mossbauer spectra of 57Fe in the chromium-substituted Zn ferrite system are reported in the temperature range 295-823K. These ferrites have been obtained by replacing a part of Fe3+ ions in ZnFe2O4 by Cr3+ ions. Well resolved quadrupole doublets are obtained for the two compositions studied. The value of quadrupole splitting increases with increasing concentration of chromium. This is attributed to the change in the oxygen parameter of the spinel structure with the addition of chromium. No detectable variation in the value of quadrupole splitting with temperature is observed and hence it is evident that the quadrupole splitting is mainly of lattice origin. The Debye temperatures of both the compositions have been calculated from the temperature dependence of the second-order Doppler shift.