Cation distribution and susceptibility study of Cd-Co and Cr3+ substituted Cd-Co ferrites

Polycrystalline ferrites with general formula CdxCo1-xFe2-yCryO4 (x = 0, 0.25, 0.50, 0.75 and 1.0; y = 0, 0.15 and 0.30) were prepared by standard ceramic method. The compounds were characterized by X-ray, IR and SEM techniques. Cation distribution in these materials is proposed by calculating the Curie temperature using weighted magnetic interaction per formula unit. Further this theoretical model is modified for trivalent substitution (Cr3+). From the AC susceptibility measurements it was found that the cobalt ferrite without (y = 0) and with (y = 0.15 and 0.30) substitution of Cr3+ consist of SD particles. Further, it was observed for cobalt ferrite that with increase in Cr3+ concentration, the normalized susceptibility increases while the Curie temperature decreases. For all the ferrite compounds it was found that the SD nature of domains is lowered initially and then increased with increase in Cd content (x = 0.50). (C) 1998 Elsevier Science B.V. All rights reserved.