Structural,electrical and magnetic properties of cobalt ferrite with Nd^(3+) doping

A systematic study on the influence of Nd^(3+) substitution on structural,magnetic and electrical properties of cobalt ferrite nanopowders obtained by sol–gel auto-combustion routewas reported.The formation of spinel phasewas confirmed by X-ray diffraction(XRD)data,and percolation limit ofNd3?into the spinel lattice was also observed.Fourier transform infrared spectroscopy(FTIR)bands observed ≈580 and ≈390 cm^(-1 ) support the presence of Fe^(3+) at A andBsites in the spinel lattice.The variation in microstructure was investigated by scanning electronmicroscopy(SEM),and the average grain size varies from 5.3 to 3.3 lm.The substitution of Nd^(3+) significantly affects the formation of pores and grain size of cobalt ferrite.Room-temperature saturation magnetization and coercivity decrease from 60 to 30 mA·m^(2)·g^(-1) and 19.9–17.8 mT,respectively,with Nd^(3+) substitution increasing.These decreases in magnetic properties are explained based on the presence of non-magnetic nature of Nd^(3+) concentration and the dilution of super-exchange interaction in the spinel lattice.The room-temperature direct-current electrical resistivity increases with Nd^(3+) concentration increasing,which is due to the unavailability of Fe^(2+) at octahedral B sites.