The role of local structure and preferential site occupancy on the saturation magnetization of the Y2.97Gd0.03Fe₅O₁₂ ferrite

Herein, we present a comprehensive crystallographic and magnetic study of the Gd 0.03 Y 2.97 Fe 5 O 12 ferrite, synthesized via the sol–gel method. Rietveld refinement and Raman spectrum confirmed the single-phase cubic structure formation. Furthermore, the atomic positions, the local structure distortion, lattice parameters (12.398(1) Å), volume (1905.6(4) Å 3 ), and the average crystallite size (68.3(9) nm) were also determined. Using a phenomenological model was confirmed that the Gd 3+ ions prefer to occupy the dodecahedral sites. The micrographic images obtained by scanning electron and transmission microscopies corroborated the agglomerated coral style of the particles. From the magnetic study, it was verified that the Gd 3+ ions induce a negative contribution to the net magnetic moment in the Gd 0.03 Y 2.97 Fe 5 O 12 ferrite. In addition, was demonstrated that the a - d super-exchange interaction weakening is not the main mechanism that determines the saturation magnetization for the studied compound. Instead, the negative contribution of the Gd 3+ ion’s magnetic moment in dodecahedral sites is the determining physical mechanism of saturation magnetization.