Investigation of structural, optical, magnetic, and electrochemical properties of La1 − xAgxFe0.5Mn0.5O3−δ perovskites

In this work, La_{1 - x}Ag_xFe_0.5Mn_0.5O_3-δ (where x = 0.10, 0.15, and 0.20) perovskite samples were prepared by sol-gel method. Rietveld refinement of XRD data revealed the single phase rhombohedral (R3c) structure at x = 0.10, 0.15 while at x = 0.20 revealed the existence of the rhombohedral (R3c) and cubic structure of Ag (space group Fm3m). TEM images of these samples showed that the aggregation of particles decreased with increasing Ag upto 0.15 then increased with increasing Ag (x = 0.20). The optical studies showed that the La_{1 - x}Ag_xFe_0.5Mn_0.5O_3-δ samples have low band gap energy values. Mössbauer spectroscopy of these samples showed that the Fe ions are present in the Fe³⁺ and Fe⁴⁺ oxidation states with oxygen vacancies (δ). XPS of the La_{1 - x}Ag_xFe_0.5Mn_0.5O_3-δ samples revealed the presence of mixed valence states of Mn and Fe ions. Magnetic hysteresis loops M (H) of the La_{1 - x}Ag_xFe_0.5Mn_0.5O_3-δ samples revealed the presence of mainly antiferromagnetic with a small amount of ferromagnetic. The electrochemical properties of the La_{1 - x}Ag_xFe_0.5Mn_0.5O_3-δ samples were enhanced with increasing Ag upto 0.15 then decreased with increasing Ag (x = 0.20). The obtained results can be used to develop perovskite materials for optical, magnetic, and energy storage applications.