Preparation of Zn_{(1−<i>x</i>)}Cd_<i>x</i>Fe₂O₄(<i>x</i>= 0.0, 0.1, 0.3, 0.5, 0.7 and 1.0) ferrite samples and their characterization by Mössbauer and positron annihilation techniques

Abstract

Single phase Zn(1?x)CdxFe2O4 (x = 0.0, 0.1, 0.3, 0.5, 0.7 and 1.0) ferrite samples have been prepared by the solid state reaction method. The room temperature M?ssbauer spectra for all the samples indicate the paramagnetic nature of the prepared samples. M?ssbauer spectra have been deconvoluted separately for the tetrahedral 'A' site and the octahedral 'B' site to identify the variations of the M?ssbauer parameters, i.e.?isomer shift, quadrupole splitting and linewidth, with the concentration of Cd doping, x, for the tetrahedral 'A' site and octahedral 'B' site. Changes of these parameters with concentration, x, confirm that the Cd2+ ions prefer to go to the tetrahedral 'A' site compared to the octahedral 'B' site in this Zn(1?x)CdxFe2O4 cubic spinel ferrite system. To study the changes in the electron momentum distributions, coincidence Doppler broadening of the electron positron annihilation ?-radiation measurement technique has been employed. The results indicate that positrons are annihilating less with the oxygen 2p electrons and other core electrons in the case of mixed (Zn(1?x)CdxFe2O4) ferrites than ZnFe2O4 or CdFe2O4 ferrites.