Rare Earth Nd3+ Doping Cobalt-Cadmium Nanoferrites Structural, Optical, and Magnetic Properties and Applications

Nanoscale particles of neodymium-substituted cobalt-cadmium generic formula for nanoferrite Co0.4Cd0.6NdxFe2−xO4 samples at X = 0.000, 0.003, 0.005, 0.007, 0.009, and 0.011 were studied. The prepared powders were synthesised at low temperatures using citrate gel auto-combustion process. The synthesised powders were calcined at 500 °C for four hours. The morphological properties of the sintered powders were investigated, and their crystal structure was determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD peaks confirmed the spinel ferrite structure. The lattice parameter was calculated from the XRD and showed decreasing trends with 8.442 to 8.308. SEM revealed an irregularly-shaped grain morphology with a homogeneous distribution. Raman spectroscopy analysis showed slight frequency changes in the Raman modes in doped samples, attributed to variations in the cation distribution. The peaks are located at 191, 291, 461, 591, and 671 cm−1. UV spectroscopy studies showed that the energy band gap values decrease with increasing Nd3+ concentration. Direct optical band gap values obtained were 1.238, 1.248, 1.199, 1.135, 1.134, and 1.101 eV with increasing Nd doping. The magnetic hysteresis properties were determined using a SQUID-VSM magnetometer. The hysteresis curves of Co0.4Cd0.6NdxFe2−xO4 nanoparticles show an increase in coercivity with increasing doping concentration. This enhancement is attributed to the multi-domain behaviour.