Comparative Study Between Ni–Co Ferrite and Multi Rare Earth Element Doped Ni–Co Ferrite

This paper reports the synthesis and analysis of structural, spectral, dielectric and magnetic properties of nano sized multi rare earth (RE) element doped Ni0.5Co0.5Gd0.002Tb0.002Dy0.002Ho0.002Er0.002Fe1.99O4 (NCFR5). The structural and functional properties of this compound was compared with the parent Ni0.5Co0.5Fe2O4 (NCF). Ni0.5Co0.5Fe2O4 and Ni0.5Co0.5Gd0.002Tb0.002Dy0.002Ho0.002Er0.002Fe1.99O4 with five different heavy rare earth elements at octahedral B-site were successfully synthesized by sol-gel method. X-ray diffraction measurements supported the spinel ferrites' single-phase formation. With doping, the lattice parameter was increased from 8.218 Ao to 8.243 Ao. Evaluation of Rietveld refinement of NCF and NCFR5 samples was done. Scanning electron microscopy surface morphology studies revealed the existence of nanoscale grains for both compositions. The existence of five RE elements in NCFR5 was proved by ICP MS analysis. Room temperature UV Diffuse Reflectance Spectroscopy was performed on NCF and NCFR5, and it was discovered that NCFR5 had a greater direct bandgap than NCF. To comprehend the distribution of ions in A and B sites, Raman and Mossbauer spectroscopy were used. It was discovered that rare earth doping significantly affected the magnetic and dielectric characteristics. Multi RE element doping increased strain sensitivity in NCFR5.