Effect of transition metal (TM = Mn, Co, Ni) doping on the structural, magnetic, and shielding properties of nano Er₂O₃

The current work aims to explore the effect of the transition metal doping on the structural, magnetic, and shielding properties of nano Er₂O₃. Nano Er_1.95TM_0.05O₃ (TM = Mn, Co, Ni) samples were synthesized using the sol-gel technique. An analysis of the crystal structure and microstructure of all specimens was carried out utilizing Rietveld full pattern fitting of XRD measurements. Upon doping, all TM cations were found to be integrated into the Er₂O₃ lattice substitutionally for Er ions, preferring the 8b crystallographic sites of the cubic bixbyite structure. Also, the lattice parameter expands, the average crystallite size reduced, and the microstrain highly enlarged by TM doping. The application of the Curie–Weiss law aided in establishing the influence of different dopants on the magnetic behavior of the Er_1.95TM_0.05O₃ samples at low temperatures under a magnetic field of 200 Oe. The inclusion of Co or Ni ions in the Er₂O₃ matrix enhances the super exchange interaction, resulting in stronger antiferromagnetic coupling between the Er ions. The Phy-X/PSD software was used to calculate the radiation shielding parameters for the samples under investigation, covering a broad energy range from 15 KeV to 15 MeV. The effect of transition metal doping of Er₂O₃ on the different radiation parameters were explored. Er_1.95Mn_0.05O₃ sample has excellent neutron shielding capabilities.