Effect of substitution on the structural and magnetic properties of Sm3+- doped / SmFeO3 in nickel-copper-zinc mixed ferrite nanoparticles

This study aimed to investigate the effect of the Sm3+ substitution/SmFeO3 phase in Ni0.2Cu0.2Zn0.6Fe2-xSmxO4 ferrite. The Ni0.2Cu0.2Zn0.6Fe2-xSmxO4 (x = 0, 0.02, 0.05, 0.08, and 0.1) ferrite compositions were prepared by a sol-gel auto-combustion route. These ferrite compositions were investigated by X-ray diffraction (XRD), Mossbauer spectra, scanning electron microscope (SEM), and magnetic hysteresis curve. The XRD results confirmed the presence of hematite Fe2O3 in Ni0.2Cu0.2Zn0.6Fe2-xSmxO4 calcined at 950 degrees C for 3 h and the SmFeO3 phase with the substituted limit of Sm3+ ions up to x = 0.05. The lattice parameter and average crystalline size depend on the synergistic effect of Sm(3+ )ion radius and compressive pressure of SmFeO3. The Fe-57 Mossbauer spectra at 295 K indicated the process of the transformation of SmFeO3 phase and the variation in Fe3+-O2--Fe3+ and Fe3+-O2--Sm3+ superexchange interaction, where the hyperfine parameters were determined with a ferromagnetic order at the critical content of x = 0.08. Furthermore, the Mossbauer spectra and magnetism measurement (coercive value close to zero) of the substituted specimens revealed the superparamagnetic phase. The saturation magnetization (M-s) inhibited the dependence of Sm3+ ion content with a maximum of 53.7 emu/g at x = 0.05 and then decreased rapidly.