Tuning the magnetic properties of a ferrimagnet

Abstract

Magnetic properties of manganese ferrite doped with lanthanum and gadolinium having compositional formula MnRExFe2−xO4 (where RE = La3+, Gd3+ and x = 0.02, 0.04, 0.06, 0.08, 0.10) synthesized by co-precipitation method have been investigated. The compositional variation of the magnetic properties for each rare earth ion was studied individually first. Then, the variation of the magnetic properties with the substitution of the two different ion having different magnetic moments was compared. Saturation magnetization of non-magnetic ion (La3+) substituted MnFe2O4 was found to be superior to that of magnetic ion (Gd3+) substituted MnFe2O4. The observed result was explained in terms of Neel’s theory of ferrimagnetism, distribution of cations and magnetic moment of the associated cations. Law of approach to saturation (LAS) was adopted to investigate the dependency of magnetization on the applied field. A strong dependence of magnetic property on the distribution of cations which is specific to the particular rare earth ion was revealed in the present study.