Effects of ZnO-doping on structural and magnetic properties of CdFe2O4

The solid-solid interaction between Fe2O3 and CdO-yielding CdFe2O4 has been monitored using an XRD and a vibrating sample magnetometer. The effect of sintering temperature and dopant concentration on the bulk density of CdO/Fe2O3 was investigated using the usual ceramic method. The results showed that the solid-solid interaction between the CdO and Fe2O3 took place at a temperature >= 600 degrees C yielding CdFe2O4 of moderate degree of crystallinity. This reaction was much stimulated in presence of ZnO and also by increasing the calcination temperature within 700-900 degrees C. On the basis of magnetic measurements the possibility of formation of CdFe2O4 was evidenced at a lower temperature (500 degrees C). These measurements also showed the stimulation effect of ZnO towards ferrite formation. The activation energy of the formation of CdFe2O4 was calculated from XRD measurements and found to be 102, 75, 66, 60 and 53 kJ mol(-1) for pure samples and those doped with 0.75, 1.5, 3 and 6 mol/% ZnO, respectively. The addition of ZnO (0-1.5 mol%) increased the bulk density of the investigated system which suffered a significant decrease upon increasing the dopant concentration above 1.5 mol% ZnO due to the formation of cadmium ferrite even for solids calcined at 500 degrees C.