Analysis of electronic configuration and spin state driving to magnetic properties of La_2xBa_0.5-xSr_0.5-xFe_0.9Ni_0.1O_3-δ (x = 0, 0.25)

Materials possessing composition La_2xBa_0.5-xSr_0.5-xFe_0.9Ni_0.1O_3-δ (x = 0, 0.25) have been successfully synthesized through self-combustion technique followed by calcination at 850 °C for 6 h and sintering at 1100 °C for 6 h. It was characterized and analyzed that the cubic structure formed in which Fe and Ni are well suited inside octahedron, and their oxidation state verified to be Fe³⁺/Fe ⁴⁺ and Ni⁴⁺/Ni⁵⁺. Furthermore, the electronic shell arrangement 3d⁴, 3d⁵, and 3d⁶ are a high spin state configuration of both Fe and Ni in Ba_0.5Sr_0.5Fe_0.9Ni_0.1O_3-δ. When La substituted Ba/Sr in La_0.5Ba_0.25Sr_0.25Fe_0.9Ni_0.1O_3-δ, the electronic configuration becomes a low spin state. The ferromagnetic hysteresis curves showed a soft magnetic hysteresis possessing M_FM^S = 0.05 emu/gr for BSFN. However, LBSFN displays a soft magnetic hysteresis suggested to present multiple magnetic phases or domain structures having M_FM^S = 0.02 emu/gr.