Influence of manganese substitution on structural and magnetic properties of CoFe2O4 nanoparticles

Nanocrystalline ferrites with general formula of Co1−xMnxFe2O4 (0 ⩽ x ⩽ 1) have been synthesized via wet chemical coprecipitation technique. Structural and magnetic investigations were performed at room temperature. The results revealed the formation of single phase Mn-substituted CoFe2O4 nanoparticles with crystallite sizes in the range 12–15 nm. An increase in lattice parameter and decrease in X-ray density were observed with increasing Mn concentration in CoFe2O4. FTIR results showed two (vibrational) frequency bands (υ1 and υ2) for tetrahedral and octahedral sites confirming the formation of spinel ferrite. Magnetic measurements showed increasing behavior of both coercivity and saturation magnetization of cobalt ferrite up to 20–30% manganese concentration followed by a monotonic decrease in these parameters for higher Mn concentrations.