Magnetic‐, Dielectric‐, and Redox‐Behavior‐Induced Energy Storage in Citrate Sol–Gel‐Derived Nanosized Sm ₂ NiFeO ₆

The present work investigates novel nanosize Sm 2 NiFeO 6 double perovskite synthesized via citrate sol–gel route. Rietveld refinement of the X‐ray diffraction pattern confirmed the formation of orthorhombic (Pbnm) structure, while Raman spectroscopy revealed characteristic vibrational modes. The surface oxidation states investigated through the high‐resolution X‐ray photoelectron spectra analysis showed the presence of Ni/Fe in +2/+3 oxidation states. The short range weak ferromagnetic/ferrimagnetic behavior with antiferromagnetic domains has been observed in Sm 2 NiFeO 6 . Further, the conduction mechanism is governed by electron hopping between Ni 2+ and Fe 3+ ions with the activation energies of ≈0.21 eV, which has effectively contributed toward enhanced energy storage performance. The specific capacitance of 65.3 F/g has been achieved at current density of 1.5 A/g with the cyclic stability of ≈97% at 7 A/g after 1000 charging/discharging cycles.